Human Papilloma virus
Human papillomaviruses ( HPV ) are common viruses that can do warts. There are more than 100 types of HPV. Most are harmless, but about 30 types put you at hazard for malignant neoplastic disease. More than 40 HPV types can be sexually transmitted, and these HPVs spread really easy through venereal contact. These types affect the genitalias and you get them through sexual contact with an septic spouse. They are classified as either low-risk or bad. Low-risk HPV can do venereal warts. Bad HPV can take to malignant neoplastic diseases of the neck, vulva, vagina, and anus in adult females. In work forces, it can take to malignant neoplastic diseases of the anus and phallus.
( hypertext transfer protocol: //www.nlm.nih.gov/medlineplus/hpv.html ) , ( Division of STD bar study, 1999 )
The Food and Drug Administration has approved two vaccinums, Gardasil and Cervarix, that are extremely effectual in forestalling relentless infections with the two HPV types that cause most cervical and anal malignant neoplastic diseases. Gardasil besides prevents infection with the two HPV types that cause most venereal warts.
( hypertext transfer protocol: //www.cancer.gov/cancertopics/factsheet/Risk/HPV )
2.1.1 Human villoma virus and its structural belongingss
HPVs cause a diverse scope of epithelial lesions. Over 100 different HPV types have been identii¬?ed based on DNA sequence analysis ( Bernard, 2005 ) , with each being associated with infection at specii¬?c epithelial sites ( Villiers de, 2001 ) . At an evolutionary degree, HPVs autumn into a figure of distinguishable groups or genera and the lesions they cause have different features. The two chief HPV genera are the Alpha and Beta papillomaviruses, with approx. 90 % of presently characterized HPVs belonging to one or other of these groups. Beta papillomaviruses are typically associated with in evident cutaneal infections in worlds but, in immunocompromised persons and in patients enduring from the familial disease EV ( epidermodys plasia verruciformis ) , these viruses can distribute unbridled and go associated with the development of non- melanoma tegument malignant neoplastic disease ( Harwood et al. , 2002, Pi¬?ster 2003 ) .
2.1.2 Virus types and its function in malignant neoplastic diseases
The Human villoma virus and their subtypes are associated with cutaneal mucosal and anogenital diseases ( Table 2.1.1 ) . HPV DNA likely found in 99.7 % of all cervical carcinomas, with HPV types 16, 18, 45 and 31 being the most frequent. ( Walboomers et al. , 1999, Koutsky et al. , 2002 ) Based on these observations, the anogenital HPVs have been divided into two groups: the first is associated with a high hazard for cervical malignant neoplastic disease development – the HR HPVs ( 16, 18, 26, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, 68, 73 and 82 ) , and the 2nd group with a low carcinogenic potency – the low-risk ( LR ) HPVs ( 6, 11, 40, 42, 43, 44, 54, 61, 72 and 81 ) ( Munoz et al, 2003 ) . It has now been proven beyond sensible uncertainty that infection with an HR HPV is a necessary requirement for the development of cervical malignant neoplastic disease, and the World Health Organization ( WHO ) has recognized HPV 16 and HPV 18 as carcinogenic agents for worlds.
More than 90 types of HPV ( infective and non-pathogenic ) have been identified. The most common 1s associated with cervical malignant neoplastic disease are types 16, and 18, which have been reported in 70 % of the instances. The deduction of the importance of pathological human Papillomavirus has non been studied in the Middle East where the incidence of malignant neoplastic disease of neck is high ( Mortazavi et al. , 2000 ) .
Persistent HPV infections are now recognized as the cause of basically all cervical malignant neoplastic diseases, every bit good as most instances of anal malignant neoplastic disease. In 2011, more than 12,000 adult females in the United States are expected to be diagnosed with cervical malignant neoplastic disease and more than 4,000 are expected to decease from it. ( American Cancer Society, Cancer Facts and Figures 2011 ) . Cervical malignant neoplastic disease is diagnosed in about half a million adult females each twelvemonth worldwide, claiming a one-fourth of a million lives yearly.
Although anal malignant neoplastic disease is uncommon, more than 5,000 work forces and adult females in the United States are expected to be diagnosed with the disease in 2011, and 770 people are expected die from it.
Genital HPV infection besides causes some malignant neoplastic diseases of the vulva, vagina, and phallus ( Parkin, 2002 ) . In add-on, unwritten HPV infection causes some malignant neoplastic diseases of the oropharynx ( the in-between portion of the pharynx, including the soft roof of the mouth, the base of the lingua, and the tonsils ) ( Parkin, 2002, D’Souza et al. , 2007 ) .
It has been estimated that HPV infection histories for about 5 per centum of all malignant neoplastic diseases worldwide ( Parkin, 2002 ) .
Nongenital Cutaneous Disease
Common warts ( verrucae vulgaris )
1, 2, 4, 26, 27, 29, 41, 57, 65
Plantar warts ( Myrmecia )
1, 2, 4, 63
Flat warts ( verrucae plana )
3, 10, 27, 28, 38, 41, 49
Butcher ‘s warts ( common warts of people who handle meat, domestic fowl, and fish )
1, 2, 3, 4, 7, 10, 28
2, 27, 57
Ungual squamous cell carcinoma
Epidermodysplasia verruciformis ( benign )
2, 3, 10, 12, 15, 19, 36, 46, 47, 50
Epidermodysplasia verruciformis ( malignant or benign )
5, 8, 9, 10, 14, 17, 20, 21, 22, 23, 24, 25, 37, 38
Nonwarty tegument lesions
Nongenital Mucosal Disease
Squamous cell carcinoma of the lung
6, 11, 16, 18
6, 11, 30
Maxillary fistula villoma
Squamous cell carcinoma of the fistulas
Oral focal epithelial hyperplasia ( Heck disease )
Squamous cell carcinoma of the gorge
6, 11, 30, 42, 43, 44, 45, 51, 52, 54
16, 18, 34, 39, 42, 45
16, 18, 31, 34
Giant condylomata ( Buschke-Lowenstein tumours )
Unspecified intraepithelial neoplasia
30, 34, 39, 40, 53, 57, 59, 61, 62, 64, 66, 67, 68, 69
Low-grade intraepithelial neoplasia
6, 11, 43
Intermediate intraepithelial neoplasia
31, 33, 35, 42, 44, 45, 51, 52
High-grade intraepithelial neoplasia
16, 18, 56, 58
Carcinoma of vulva
6, 11, 16, 18
Carcinoma of vagina
Carcinoma of neck
16, 18, 31
Carcinoma of anus
16, 31, 32, 33
Carcinoma in situ of phallus ( erythroplasia of Queyrat )
Carcinoma of phallus
16, 18Table 2.1.1: Diseases and Associated HPV Subtypes
2.2 Human Papilloma virus Pathogenesis
2.2.1 Pathogenesis of virus in malignant neoplastic diseases
Papillomaviruses have icosahedral symmetricalness and are non-enveloped. Seventy-two capsomeres surround the genome. A major and minor mirid bug protein comprises the outer protein coat of the virus. Approximately 8000 base braces comprise the closed, dual stranded- round HPV genome.
Fig. 2.1: Chart I – HPV Gene Coding Regions
Coding information for HPV exists on one strand ; it is believed that written text occurs in a clockwise way from a individual booster part ( P97 ) . Three major parts comprise the HPV genome. The early part ( E1-8 ) consists of cistrons responsible for written text, plasmid reproduction, and transmutation. The late part codifications for the major ( L1 ) and minor ( L2 ) mirid bug proteins and the control part contains the regulative elements for written text and reproduction.
HPV infection occurs at the basal epithelial tissue. Although the incidence of infection is high, most infections resolve spontaneously. A little proportion of septic individuals become persistently infected ; relentless infection is the most of import hazard factor for the development of cervical malignant neoplastic disease precursor lesions.
The most common clinically important manifestation of relentless venereal HPV infection is cervical intraepithelial neoplasia, or CIN. Within a few old ages of infection, low-grade CIN called CIN-1 may develop, which may spontaneously decide and the infection clear.
Fig. 2.2 Natural History of HPV Infection
Persistent HPV infection, nevertheless, may come on straight to top-quality CIN, called CIN2 or CIN3. High-grade abnormalcies are at hazard of patterned advance to malignant neoplastic disease and so are considered malignant neoplastic disease precursors. A little proportion of top-quality abnormalcies spontaneously regress. If left undetected and untreated, old ages or decennaries subsequently CIN2 or 3 can come on to cervical malignant neoplastic disease.
Infection with one type of HPV does non forestall infection with another type. Of individuals infected with mucosal HPV 5 % to 30 % are infected with multiple types of the virus.
It is believed that the HPV virus enters the organic structure after little injury to the epithelial tissue and needs terminally differentiated epithelial cells for reproduction. Late-region cistrons are expressed in the differentiated cells near the epithelial tissue ‘s surface supplying an easy manner of viral transmittal. Early part cistrons are expressed in the basal cells of the epithelial tissue but are unable to bring forth virus since these cells do non do the mirid bug proteins encoded by the late cistrons.
All types of HPV replicate merely within the host cell ‘s karyon, but the mechanism by which HPV types transform cells is ill-defined. Most surveies focus on HPV-16 and HPV-18, the viruses most often associated with anogenital carcinomas. The HPV genome replicates as an excess chromosomal episome or plasmid in benign HPV-associated lesions. However, the viral DNA is frequently integrated into the host ‘s chromosome in malignant HPV associated lesions. E6 and E7 cistrons are strongly associated HPV-mediated carcinogenesis.
Another survey bespeaking a positive association between HPV 16 and high class lesions, suggests that extra cofactors, such as coffin nail smoke, may be required as a carcinogen to progress HPV-infected cells toward neoplastic patterned advance. All HPVs infect the mucose membranes of the tegument. However, the assorted signifiers of HPVs will set up themselves in distinguishable cell types. Therefore, HPVs are divided into three classs: venereal mucosal and nongenital cutaneal types and types specific for epidermodysplais verruciformis. Furthermore, people who have seeable venereal warts can be infected with multiple HPV types at the same time.
Most HPV infections are symptomless. However lesions can develop anyplace in a clip frame between three hebdomads and eight months after infection, with most developing 3 months after infection. Of the HPVs characterized with an oncogenic consequence, it is shown that carcinoma seldom develops instantly after infection.
HPV-6 and HPV-11 are most normally associated with venereal warts. While the most common presentation is warts, or condylomata, many infections are detected merely by Pap smear cytological grounds. In contrast to the strong association between cervical intraepithelial neoplasia and HPV, the relationship between HPV and squamous epithelial lesions is less clear. One survey ‘s findings support the hypothesis that HPV may be associated in the development of ovarian squamous intraepithelial neoplasia.
2.2.2 Pathogenesis of human villoma virus in unwritten malignant neoplastic diseases
Human papillomaviruses infection is known to be a necessary component for the development of cervical malignant neoplastic disease in adult females and is besides a hazard factor for the development of anal, penial, and vulvar malignant neoplastic diseases. The site that is largely associated with HPV infection in the caput and neck country is the oropharynx, peculiarly the tonsils and tongue base. It is non clear why the oropharynx is more susceptible to HPV transmutation.
The mechanism of Human papillomaviruses carcinogenesis was first characterized in cervical malignant neoplastic disease, where more than 90 % of instances are related to HPV infection. Human papillomaviruses have been categorized by their genotypes into low-risk and bad types harmonizing to the hazard of that virus doing squamous cell carcinoma of the uterine neck ( Steben et al. , 2007 ) . Infection of the uterine neck with any human papillomavirus ( HPV ) genotype is associated with bad sexual behavior, peculiarly if started at a younger age ; and relentless infection of the uterine neck with bad HPV genotypes, particularly HPV-16 and HPV-18, is indispensable for the development of squamous cell carcinoma ( SCC ) ( Walboomers et al. , 1999, Monk et al. , 2007 ) .
Recent grounds besides incriminates bad HPV-genotypes in the pathogenesis of unwritten and oropharyngeal SCC ( Miller et al. , 2001, Mork et al. , 2001, Syrjanen et al. , 2003, Gillison et al. , 2004, Syrjanen S, 2005, Licitra et al. , 2006, D’Souza et al. , 2007, Haddad RI, 2008 ) . HPV infection of the oral cavity and of the oropharynx like HPV infection of the uterine neck, is associated with bad sexual behavior, in peculiar with oro venereal sex ; and bad HPV genotypes, in peculiar HPV-16, are present in many unwritten and oropharyngeal SCC where in some instances they likely play an indispensable aetiological function ( D’Souza et al. , 2007 ) . Persons with oropharyngeal SCC in which HPV can be detected intracellularly have a better forecast than individuals with HPV-cytonegative oropharyngeal SCC ( Gillison et al, 2000, Licitra et Al. , 2006 ) .
The presentation of HPV DNA, even of bad HPV transforming genes in squamous cell carcinoma is non in itself sufficient grounds of oncogenesis by the HPV in that context. HPV may good hold been either present but a non-participant during the oncogenesis, or have been superimposed upon the malignance. On the other manus, absence of HPV DNA from any carcinoma does non except the theoretical possibility of its holding played some function in the induction of the malignance since HPV infections are often transeunt ( Mork et al, 2006 ) . In such a ‘hit and run ‘ state of affairs, HPV may motivate initial transmutation in cells that later lose their HPV DNA sequences during carcinogenesis ( Syrjanen, 2003 ) . However, this is extremely unlikely since continuity of oncoproteins E6, E7 of the bad HPV genotypes appears to be necessary for the prolongation of HPV-associated malignance, as is apparent from the presence of HPV DNA in the cells of SSC of the uterine neck.
Acquisition of unwritten and oropharyngeal HPV infection
Both unwritten and oropharyngeal HPV infection and unwritten and oropharyngeal SCC are associated with the pattern of orogenital sex and with the bad sexual behavior of live togethering with many spouses, peculiarly when started at a younger age ( Mork et al. , 2001, Gilson et al. , 2004, Syrjanen. , 2007, D’Souza. , 2007, Kreimer et al. , 2004 ) . In a survey chiefly aimed at vulvogenital HPV infection, baccy smoke and increasing age were found to be risk factors associated with increased frequence of relentless unwritten HPV infections in adult females. This appears to be because tobacco-mediated and age-related local familial and immune deregulating renders the tissues more susceptible to HPV infection ( D’Souza et al. , 2007 ) .
Although unwritten and oropharyngeal HPV infections are chiefly sexually acquired, oral cavity to talk contact between spouses and between household members, autoinoculation, and perpendicular birth-transmission are besides routes whereby HPV infection of unwritten and oropharyngeal sites can be established ( Fakhry et al. , 2006 ) . As unwritten and oropharyngeal subclinical HPV infection is non uncommon, it is possible that the epithelial tissue may function as a reservoir of the virus and when activated the virus may play a function in HPV-associated unwritten and oropharyngeal SCC.
HPV in unwritten and oropharyngeal squamous cell carcinoma
The HPV E6 and E7 transforming genes, which encode proteins dwelling of 151 and 98 amino acids, severally, are mostly responsible for the oncoming and continuity of the malignant procedure in both anogenital and caput and cervix malignant neoplastic diseases. E6 and E7 are best known for their ability to adhere and demobilize the tumour suppressers p53 and pRb, and these several belongingss have been associated with their oncogenic potency. The E6 protein contains zinc-binding motives and can organize a complex with the p53 tumour suppresser protein of the host cell, bring oning p53 debasement. The E7 protein signifiers complexes with retinoblastoma cistron household proteins, which are negative regulators of cell growing. This consequences in the release of the E2F written text factors in the cell. The free E2F activates the look of several host cistrons involved in the cell rhythm patterned advance, and the E6/E7-inactivated p53 and pRb-related proteins permit the cell to get away normal cheque points, with subsequent loss of DNA reproduction. The coincident effects of loss of both p53 and pRb map may take to the malignant transmutation of epithelial cells.
This absence of familial or epigenetic changes in the p53 and pRb tracts in HPV-positive SCCHN is in crisp contrast to what is observed in HPV-negative disease. Typically, p53 mutants are often observed in the HPV-negative squamous cell carcinomas. By contrast, HPV-positive carcinomas normally do non incorporate any p53 mutants, and occur preponderantly in patients with no inordinate baccy and/or intoxicant ingestion history. These differentiations imply that HPV-positive and HPV-negative carcinomas of the caput and cervix represent distinguishable entities. Furthermore, it has been suggested that the forecast of patients with HPV-positive tumours is better than that of patients with a smoke related, HPV negative tumour. The association between HPV infection and other tumour suppresser cistrons, such as p16, is besides of involvement. The p16 protein maps as a tumour suppresser by adhering to the cyclin D1 CDK4/CDK6 composite, forestalling phosphorylation of the Rb protein. Overexpression of p16 protein has been reported repeatedly in HPV-associated malignant neoplastic diseases, and one of survey, merely the HPV-positive/p16 expressing tumours near to 25 % of tumours analyzed were the 1s associated with favourable forecast.
In epidemiological surveies, SCC of the caput and cervix is often treated as a homogenous group, and the assorted constituent carcinomata ( unwritten, oropharyngeal, laryngeal, nasopharyngeal, hypopharyngeal etc. ) are non frequently separated out statistically. The reported rates of sensing of HPV DNA in caput and cervix SCC scope from 0 to 100 % ( Syrjanen et al. , 2007, Ha et al. , 2004 ] . This utmost fluctuation in reported prevalence may be owing to chunking together of basically different lesions ; to little sample Numberss ; and to differences in the sampling techniques ; in the ethno-geographic beginnings of the topics examined ; and in the HPV sensing methods applied.
2.2.3 Pathogenesis of human villoma virus in cervical malignant neoplastic diseases
As long ago as 1995 the causative association between HPV and SCC was recognised ( International Agency for Research on Cancer, 1995 ) . The HPV household of viruses contains more than 100 types ; some HPVs cause benign tegument warts, or villoma, for which the virus household is named. Approximately 40 HPV types affect the venereal country. They can be sub-divided into those that are low hazard for cervical malignant neoplastic disease ( such as HPV-6 and HPV-11, which are responsible for doing venereal warts ) and those which are high hazard for cervical malignant neoplastic disease. The high hazard types happening most often in cervical malignant neoplastic disease include HPV-16 and HPV-18 ; together these history for over 70 % of SCCs ( Munoz, 2004 ) . HPV-18 is besides thought to account for about 50 % of all glandular cancer.
At least 15 human papillomavirus ( HPV ) types are human carcinogens that play a cardinal function in the pathogenesis of cervical malignant neoplastic disease and other less common malignant neoplastic diseases, including vaginal, vulvar, anal, penial, and upper aerodigestive piece of land malignant neoplastic diseases ( Munoz N et al. , 2003, Gillison ML et al. , 2003 ) Worldwide, cervical malignant neoplastic disease is the 2nd most common malignant neoplastic disease in adult females, with the bulk of instances ( ~80 % ) happening in developing states ( Parkin DM et al. , 2001 ) . In the US and other developed states, cervical malignant neoplastic disease is no longer a taking cause of cancer-related mortality ( Rieslag et al. , 2002 ) because adult females undergo everyday Pap showing and are treated if cervical intraepithelial neoplasia ( CIN ) is diagnosed. CIN, nevertheless, continues to do important psychological and physical morbidity.
The association between certain strains of HPV and cervical malignant neoplastic disease is good known. In the West, cervical malignant neoplastic disease is the 4th most common malignant neoplastic disease in adult females. In developing states though, it is the most common malignant neoplastic disease, with 1/2 million new instances per twelvemonth. Overall, it is the most common virus associated malignant neoplastic disease worldwide, followed by hepatocellular carcinoma, NPC and Burkitt ‘s lymphoma. There is now compelling grounds for an aetiological function of HPV in cervical and other malignant neoplastic diseases.
A ) Epidemiologic Evidence:
It has been known for a long clip that the incidence of cervical Cancer. is related to sexual activity. Promiscuous adult females are far more likely to develop cervical malignant neoplastic disease. Nuns seldom acquire cervical malignant neoplastic disease. Several sexually transmitted agents have been implicated including Herpes Simplex. It is now just to state that grounds of a function for HSV is really slender and now really much discounted.
B ) Virological Evidence:
It has now been proven that certain precancerous conditions for cervical and vulvar malignant neoplastic disease, viz. CIN and VIN, are caused by HPV. Normal human epithelial tissue from the neck and epithelial tissue purposefully exposed to HPV 16 were transplanted to nude mice. ( Immunologically immature mice which are non able to reject the transplant ) . Weeks subsequently, lesions that resemble CIN histologically were detected in the epithelial tissue which was infected by HPV.
HPV genomes can be detected in 90 – 95 % of tumour cell lines. HPV genomes can be found at a lower frequence in pre cancerous province such as CIN1, CIN2 and CIN3. HPV 16 and 18 are the most normally found. However, other strains may be present, particularly in the less dysplastic lesions. Types 6 and 11 are normally present in the less dysplastic lesions but non in the more dysplastic 1s.
HPV DNA persists in an episomal signifier in normal septic cells but is integrated in the host cell chromosome in malignant cells. The integrating of HPV DNA appears to be random. It is thought that as integrating occurs, the breakage ever occurs in the E1 part. One of the maps of the E1 part is to negatively command the look of the E6 and E6 cistrons. Therefore, it is thought that as a consequence of the integrating, the E1 map is lost and the E6 and E7 cistrons are derepressed. This leads to an overrun of the E6 and E7 cistron merchandises. E6 is shown to demobilize p53 and E7 the Rb proteins.
HPV DNA is biologically active in vitro. It is able to transform human fibroblasts and keratinocytes. It has effects on epithelial cell distinction and induces DNA reproduction in the fibroblast. All the above effects can be nailed down to the E7 reading frame. The changeless look of the E7 and possibly the E6 reading frames merchandises are indispensable for the care of transmutation.
Antibodies to HPV are more prevailing in patients with CIN or invasive Ca. Gissman et Al. looked at the prevalence of antibodies to the E7 and E4 HPV proteins in normal people and those with cervix malignant neoplastic disease. Although the prevalence of Abs to E4 and E7 were increased in patients with Cervix malignant neoplastic disease compared to the controls. The prevalence of Ab to E7 was much higher ; There was merely a 2 fold difference in the prevalence of Ab to E4 between the malignant neoplastic disease patients and the normal controls. However there was a 7-fold difference in the prevalence of Ab to E7. This suggests that there may be a function for proving for Ab to the E7 protein in hereafter for usage as a marker in supervising the effectivity of intervention. However, it is really of import to hold the right protein antigen of the peculiar strain of HPV involved.
It must be born in head that other factors are involved in the tumourigenesis of cervical malignant neoplastic disease
The existent site in the organic structure
The HPV type
The immune position of the patient ; immunocompromised patients have a much higher hazard of developing cervix malignant neoplastic disease.
Vitamin A lack
3. Association with tumors in immunocompromised persons
10 % of the general population have warts at any one clip but warts and tegument malignant neoplastic diseases are much more common and of a greater job in immunocompromised patients, in peculiar nephritic grafts and people with AIDs. The existent Numberss of people undergoing nephritic graft operations have increased bit by bit in the last 20 old ages. As survival times increased, it became evident that many of them are developing serious jobs with warts and tegument malignant neoplastic diseases. The job seems to be related to the care immunosuppressive therapy, which is prescribed to patients as long-run therapy after their operation. Prednisolone and Azothiaprine are the 2 most common immunosuppressors given.
Many nephritic graft patients appeared with horrific intractable warts in all parts of the organic structure. The warts could non be controlled by any methods but may react to the backdown of the immunosuppressive therapy. Some of these patients with warts progressed onwards to malignancy in many parts of the organic structure at one time. Several factors are known to lend to malignance:
Oncogenic effects of the drugs given
Chronic antigenic stimulation
The longer the transplant survives, the more likely that patient will develop warts and tegument malignant neoplastic diseases.
Table 2.2 Graft endurance in different phases
Age of Patients
& lt ; 5 old ages
& gt ; 5 old ages
The widespread visual aspect of warts in nephritic graft patients resembles those found in the status Epidermaldysplasia Verruciformis ( EV ) . EV is a rare autosomal recessionary status characterized by the visual aspect of widespread warts on the surface of the organic structure and 30 % of the development of squamous cell carcinomas ( SCC ) . Over 20 types of HPV are associated with EV and the HPV DNA exists chiefly in the episomal signifier in the lesions of these patients. In nephritic transplant subsisters the ratio of basal cell carcinoma to SCC is 1:15 compared to a ratio of 1:5 for a normal population. The female nephritic graft patients are besides at a much higher hazard of developing cervical Ca. , CIN and VIN than the normal population. The precise function of HPV in the causing of tegument malignant neoplastic diseases in the renal-transplant patients is non known. The skin lesions do resemble those of EV on visual aspect and the Deoxyribonucleic acid of HPV 5 and 8 ( the HPV strains normally isolated from patients with EV ) are found in 50 % of SCC of the nephritic graft patients. HPV 5 and 8 may move as inducing agents for the development of tegument tumors. In a recent survey, it was claimed that the prevalence of anti-HPV 8 Ab is increased in patients with skin tumors:
Table 2.3: Percentage of prevalence of anti HPV Antibody in patients
Basal Cell Carcinoma
Squamous Cell Carcinoma
If the above can be substantiated, so HPV may hold a far more baleful function in human malignant neoplastic diseases than antecedently thought. It may hold a function in bring oning the development of tegument and other epithelial malignant neoplastic diseases. It is non clear whether a backdown of immunosuppressive therapy will hold a good consequence on tegument malignant neoplastic diseases. Although some patients with intractable malignant neoplastic disease jobs have been offered a backdown of immunosuppressive therapy. There have been no instances of metastasis from a SCC arising in an ex-renal graft patient to day of the month. A
4. Continuity of HPV infection
There is circumstantial grounds that HPVs may prevail in the squamous epithelial tissue, without bring forthing recognizable lesions, in a manner similar to the continuity of polyomaviruses in the kidney. Up to 42 % of homograft receivers develops cutaneal lesions within a twelvemonth after graft. This suggests that transplanted patients see either new infections or reactivation of latent virus. HPV DNA sequences have been found in biopsies of normal countries of the voice box of persons who have had perennial episodes of laryngeal villoma.
2.2.4 Structure belongingss of marks
Infection with oncogenic human papillomavirus ( HPV ) , most frequentlyHPV16, is the most signii¬?cant hazard factor in the aetiology of cervical malignant neoplastic disease, as shown by the highly high frequence ( 99.7 % ) of HPV DNA detected in cervical malignances ( Walboomers et al. , 1999 ) . Both in vitro and in vivo surveies show that the maps of the E6 and E7 proteins of the ‘high-risk ‘ HPVs are indispensable for cellular transmutation. The viral oncoproteins E6 and E7 from ‘high-risk ‘ HPVs have been shown to change tracts involved in cell-cycle control, interacting with and neutralizing two of import tumor suppressers, p53 and Rb ( Vousden et al. , 1988 ) . The loss of activity of these two tumors suppressers consequences in an uncontrolled uninterrupted cellular proliferation taking to cell transformation.HPV16 E6 ( 16E6 ) is a little protein composed of 151 or 158 aa, depending on the induction codon used. 16E6 contains two zinc-binding spheres and a C-terminal PDZ-binding sphere ( Mantovani & A ; Banks, 2001 ) . With the aid of the cellular ubiquitinligase E6AP, 16E6 mediates the debasement of p53 ( Scheffner et al. , 1990 ) . So far, the parts of E6 involved in adhering to either p53 or E6AP have largely been investigated by executing point mutants or omissions of E6 ( Cooper et al. , 2003 ; Fosteret al. , 1994 ; Gewin & A ; Galloway, 2001 ) . The E7 protein binds to the sodium thiosulphate phosphorylated signifier of Rb, ensuing in the break of Rb/E2F composites and reversal of the G1/S cell-cycle checkpoint. The E6 and E7 proteins inactivate tumour suppressers p53 and retinoblastoma ( Rb ) severally and render the dislocation of cell rhythm ordinance. Hence, bad HPV-infected cells develop genomic instability, which can take to the patterned advance of malignant neoplastic disease.
2.2.5 Genomic organisation of marks proteins
Human papillomaviruses ( HPVs ) belong to the Papillomaviridae household and are little, nonenveloped, icosahedral DNA viruses. The viral atoms are 55 to 60 nanometers in diameter and consist of a individual molecule of a double-stranded covalently closed round DNA genome of about 7900 bp. The genomic organisation of all papillomaviruses is unusually similar ( Fig 2.3 ) . Viral DNA is associated with cellular histones to organize a chromatin-like composite. All cryptography sequences are located on one Deoxyribonucleic acid strand merely. Most papillomaviruses contain six early ORFs and two late ORFs. There is a part with no ORFs which is designated the long control part ( LCR ) , the upstream regulative part ( URR ) , or the noncoding part ( NCR ) .
Fig.2.3 Genomic organisation of HPV-16
ORFs deduced from the Deoxyribonucleic acid sequence are designated E1 to E7, L1, and L2, indicated in Grey boxes. A non-coding part ( NCR ) is indicated by a black box. Main maps of cistrons are listed.
The HPV E6 and E7 proteins are the lone two viral cistrons expressed in virtually all HPV-positive cervical carcinomas, and many lines of experiments have shown that these are concerted viral oncoproteins ( Munger et al, 2004 ) . The activities of E6 and E7 that are most clearly linked to carcinogenesis are their abilities to demobilize the p53 and the retinoblastoma ( pRb ) tumour suppressers, severally. Bad HPV E6 proteins adhere straight to E6AP, a cellular lar ubiquitin ligase encoded by the UBE3A cistron, doing its substrate specificity to be altered so that it stably associates with and polyubiquitylates p53, ensuing in debasement of p53 by the 26S proteasome.
Therefore E6 Acts of the Apostless ( at least in portion ) as an oncoprotein by exciting the devastation of possibly the most of import tumour suppresser proteins in human malignant neoplastic disease. The E7 protein besides promotes the proteasome dependent debasement of pRb.
2.3 Material and Methods
2.3.1 Human Papilloma virus and powerful marks for unwritten and cervial malignant neoplastic diseases
The HPV is a member of the papovaviridae household and contains a double-stranded DNA virus. The papillomaviruses are a diverse group and have been detected in a broad assortment of animate beings every bit good as in worlds. The virus contains a double-stranded, round DNA genome incorporating 7800~7900 base brace, a non enveloped virion, and an icosahedral mirid bug. Because of the clinical importance, human papillomaviruses have been extensively studied, and at present about 118 different subtypes with limited DNA homologies have been identified.
In epidemiological surveies, SCC of the caput and cervix is often treated as a homogenous group, and the assorted constituent carcinomata ( unwritten, oropharyngeal, laryngeal, nasopharyngeal, hypopharyngeal etc. ) are non frequently separated out statistically. The reported rates of sensing of HPV DNA in caput and cervix SCC scope from 0 to 100 % ( Syrjanen S. , 2007, Ha PK et Al, 2004 ) . In a meta analysis of informations from 94 surveies of a sum of 4580 specimens, Miller and Johnston ( 2001 ) determined that the prevalence of HPV in normal unwritten mucous membrane and in unwritten SCC is likely to be 10 % and 46.5 % , severally ( Miller SC et al. , 2001 ) .
Serum antibodies against L1, E6 and E7 proteins of HPV-16 were detected in good over 60 % of individuals with oropharyngeal SCC ( D’Souza et al, 2007 ) . Since antibodies to HPV-16 mirid bug protein L1 are strongly associated with unwritten and oropharyngeal SCC, and since these antibodies are grounds of long-run exposure to HPV-16, it is possible, so likely, that exposure to HPV-16 precedes the development of oropharyngeal SCC by several old ages ( Mork J et al. , 2001, Syrjanen S. , 2007, D’Souza et Al, 2007 ) . However, this observation must be interpreted with cautiousness since other HPV infections, for case anogenital and unwritten warts will increase HPV antibody titers, and this can confuse the ascertained association between serum HPV antibody degrees and unwritten and oropharyngeal SCC ( Mork J et al. , 2001 ) . As is the instance with the virus itself, HPV-16 seropositivity is strongly associated with increased hazard of developing HPV-cytopositive oropharyngeal SCC, but there is merely a weak association for unwritten SCC ( Pintos J et Al.,2008, Furnis CS, 2007 ) .
HPV-associated and non HPV-associated ( tobacco/alcohol related, idiopathic ) unwritten and oropharyngeal SCC are different in cytogenetic profiles, clinical features and classs of the disease ( Gillison et al, 2000, Gillison et al. , 2000 ) . While HPV-associated cytopositive viva voce and oropharyngeal SCC is thought to be initiated and maintained by bad HPV E6/E7 oncoprotein-induced dysregulation of cell rhythm control mechanisms, taking to genomic instability ( Gillison et al.,2000, D’Souza et Al, 2007 ) , HPV-cytonegative unwritten and oropharyngeal SCC frequently show mutant of p53 tumour-suppressor cistron frequent loss of heterozygosity ( LoH ) at chromosomal venue 3p, 9p and 17p, normal or increased degrees of pRb, and reduced degrees of p16INK4A [ Braakhuis BJ et Al,2004 ] . HPV-associated and non-HPV-associated infective mechanisms result in clearly different cellular molecular features ( Gillison ML, et al 2004, Haddad RI et Al, 2008 ) .
A function for HPV in oropharyngeal tumours is farther substantiated by distinguishable molecular familial changes in HPV-positive versus HPV negative tumours. As for many malignant neoplastic diseases, inactivation of the p53 and pRb tracts is a common event in the molecular patterned advance of HNSCC. However, inactivation occurs by different mechanisms in HPV-positive and -negative tumours. In HPV-positive HNSCC, familial changes are rei¬‚ective of viral transforming gene map. For case, HPV-positive tumours tend to hold wild-type p53, because p53 is functionally inactivated by viral E6 oncoprotein ( Gillison ML et al. , 2000, Wiest T et al. , 2002, Hafkamp HC et Al, 2003. , Balz V et Al, 2003, Haraf DJ et Al, 1996. , Lindel K et Al, 2001, 39. Brachman DG et Al, 1992, Chiba I et al, 1996 ) . By contrast, HPV-negative tumours have specii¬?c p53 mutants demonstrated to be induced by carcinogens in baccy fume ( Gillison ML et al. , 2000, Wiest T et al. , 2002, Hafkamp HC et Al, 2003. , Balz V et Al, 2003, Haraf DJ et Al, 1996. , Lindel K et Al, 2001, 39. Brachman DG et Al, 1992, Chiba I etal, 1996 ) .
As another illustration, pRb map is inactivated by viral E7 protein in the HPV-positive tumour, but in HPV-negative tumours, the pRb tract is altered by other mechanisms, including amplii¬?cation of cyclin D and inactivation of p16. More complex differences in parts of chromosomal loss and addition have been demonstrated in HPV-positive versus-negative tumours through techniques such as comparative genomic hybridisation and microsatellite analysis.
2.3.2 Resources for the ligands readying:
The undermentioned resources were usage for the ligands 3 dimensional and PDB ( Protein databank ) file format for Insilco target- ligand interactions.
National Center for Biotechnology Information ( NCBI ) : This is one of American authorities resource for the for molecular biological science information, NCBI ‘s mission is to make new information engineerings to assist in the apprehension of cardinal molecular and familial procedures that control wellness and disease. The NCBI has been exciting with making automated systems for hive awaying and analysing understanding about molecular biological science, biochemistry, and genetic sciences ; easing the usage of such databases and package by the research and medical community ; organizing attempts to garner biotechnology information both nationally and internationally ; and executing research into advanced methods of computer-based information processing for analysing the construction and map of biologically of import molecules.
( hypertext transfer protocol: //www.ncbi.nlm.nih.gov/ )
Pubchem Compound Database for aggregation of chemical construction of ligands:
PubChem database was released in 2004. This database provides information on the biological activities of little molecules. PubChem is constructed which governs the three linked databases within the NCBI ‘s Entrez information retrieval system. These are PubChem Substance, PubChem Compound, and PubChem BioAssay. PubChem besides provides a fast chemical construction similarity hunt tool. Information related to utilize each constituent database may be found utilizing the links in the home page of this database through NCBI place page ( hypertext transfer protocol: //pubchem.ncbi.nlm.nih.gov/ ) .
The links from PubChem ‘s chemical construction records to other Entrez databases provide information on biological belongingss. These include links to PubMed scientific literature and NCBI’sprotein 3D construction resource in this database. This has been used to obtain the 3-D constructions of ligands for the insilico interaction survey of compounds.
ChemDraw Pro 13.0 for the ligands structures coevals: ChemDraw is the pulling tool of pick for chemists to construct publication-ready, scientifically intelligent drawings for usage in databases and publications. The tools besides can be usage for questioning chemical databases.
This is of import set of tools to manage substructural question types ( such as variable points of fond regard, ring/chain size, R groups, atom/bond/ring types, and generic atoms ) ensures that compounds are rapidly and accurately located by hunts, no affair how they are stored in commercial, public or in-house databases.
( hypertext transfer protocol: //www.cambridgesoft.com/Ensemble_for_Chemistry/ChemDraw/ )
2.4 Consequences and Discussion
Cancers arise by an evolutionary procedure as bodily cells mutate and get away the restraints that usually rein in their indecent enlargement. Consequently, multiple mechanisms have arisen to prevent uncontrolled cell division. Some of these are devices within the cell, such as those that limit cell-cycle patterned advance, whereas others are societal signals that prompt a cell to stay within its supportive microenvironment. In combination, these tumour stamp downing mechanisms are unusually effectual and can know apart between neoplastic ( abnormally turning ) and normal cellular provinces and expeditiously squelch the former without stamp downing the latter. It is interesting to observe that many, possibly all, webs that thrust cell proliferation seaport intrinsic growth-suppressive belongingss. Such unconditioned inhibitory maps obscure any immediate selective advantage that mutants in such tracts might otherwise confabulate. Because no individual tract confers a net growing advantage, any proto-cancer cell geting any individual oncogenic mutant is efficaciously trapped in an evolutionary cul-de-sac. By contrast in normal cells, coordinated extra-cellular cues activate multiple tracts in concert. In this manner the built-in growth-suppressive activity of each tract is gated by another, thereby unlocking the cell ‘s proliferative potency. However, deregulating of one or more of these activities may finally take to malignant neoplastic disease.
Table-2.5.1 Selected Anticancer Ligands for unwritten and cervical malignant neoplastic diseases marks based on Ayurveda
No. of Ligands
Ligands with CID
( Compound Identifier No )
Structure of Ligands
Bis Demethoxy curcumin
( CID_5315472 )
( CID_689043 )
( CID_1548943 )
( CID_10460395 )
( CID_10054109 )
( CID _1794427 )
( CID_969516 )
Curcumin di piporyl ester
( CID_ 6441419 )
( CID _5354238 )
( CID_5324476 )
Di benzoyl methane
( CID_8433 )
Pdb construction generated
Pdb construction generated
Pdb construction generated
( CID_3314 )
( CID_445858 )
( 1,3Diarylpropenones )
Pdb construction generated
( CID_853433 )
( CID_5370536 )
( Flavnoids )
( CID_5280343 )
( CID_133145 )
Pdb construction generated
( CID_31211 )
Turmeric has been used for 1000s of old ages in Ayurvedic and traditional Chinese medical specialty. In modern times, curcumin, the xanthous pigment of the spice Curcuma longa, continues to be used as an alternate medicative agent in many parts of South East Asia for the intervention of common complaints such as gastric disturbance, flatulency, icterus, arthritis, sprains, lesions and skin infections among many others. Curcumin is a constituent of Curcuma longa ; the xanthous spice derived from the roots ( rootstocks ) of the works Curcuma longa. Curcuma longa is a short-stemmed perennial, which grows to about 100 centimeters in tallness. It has curved foliages and oblong, ovate or cylindrical rootstocks. Curcuma longa grows of course throughout the Indian subcontinent and in tropical states, peculiarly South East Asia. A traditional redress in “ Ayurvedic medical specialty ” and ancient Indian healing system that dates back over 5,000 old ages, Curcuma longa has been used through the ages as an “ herbal acetylsalicylic acid ” and “ herbal Cortone Acetate ” to alleviate uncomfortableness and redness associated with an extraordinary spectrum of infective and autoimmune diseases ( Sharma et al. , 2005 ) .
Curcumin, chemically it is known as diferuloylmethane ( C21H20O6 ) , has been the topic of 100s of published documents over the past three decennaries, analyzing its antioxidant, anti-toxic, anti-inflammatory, malignant neoplastic disease chemopreventive and potentially chemotherapeutic belongingss ( Campbell et al. , 2005, Sharma et al. , 2005 ) . The pharmacological medicine and putative anticancer belongingss of curcumin have been the topic of several reappraisal articles published since 1991, which predate a figure of clinical surveies of curcumin which have been completed and published within the last few old ages ( Ammon et al. , 1991 ) .The anticancer compounds taken for the insilico interaction surveies for unwritten and cervical malignant neoplastic disease are listed ( Table-2.5.1 ) .