An association between human papillomavirus 16/18 deoxyribonucleic acid in peripheral blood with p16 protein expression in neoplastic cervical lesions

BACKGROUND: Human papillomavirus (HPV) infection plays a crucial role in cervical carcinogenesis. Apart from the detection of p16 protein in cervical tissues, the feasibility of the presence of HPV DNA in peripheral blood being an auxiliary marker of cervical lesions was examined. METHODS: Peripheral blood samples and cervical tissues, from 36 cervical tissues from high-grade squamous intraepithelial lesions (HSIL) and 31 early invasive cervical cancers (EICC), were analyzed for HPV 16/18 DNA and HPV 16/18 E7 mRNA expression, as well as the in situ expressions of p16 and pRb to investigate the in-between associations. RESULTS: The prevalence of HPV 16/18 DNA in patients with EICC was relatively higher than those of HSIL, in both of cervical tissues and peripheral blood. The presence of HPV 16/18 DNA in peripheral blood was positively correlated with that in cervical tissue, as well as with p16 overexpression in cervical tissues together with a significant correlation between E7 mRNA and pRb and p16 protein expressions. DISCUSSION: A positive correlation between the presence of HPV 16 or 18 DNA in peripheral blood and p16 overexpression in tissues of patients with cervical lesions was confirmed. Together with p16 immunostaining in cervical tissues, the detection of high-risk HPV 16 or 18 DNA in peripheral blood may act as an auxiliary biomarker for HPV-associated neoplastic cervical lesions.     

The Association of Molecular Biomarkers in the Diagnosis of Cervical Pre-Cancer and Cancer and Risk Factors in Senegalese

Background: Cervical intraepithelial neoplasia (CIN) grading is subjective and affected by substantial rates of discordance among pathologists. Although recent studies have suggested that p16INK4a may be a useful surrogate biomarker of cervical neoplasia, Ki-67 and human papillomavirus testing have also been shown to be useful in detecting neoplasia. The purpose of this study was to determine the expression of p16INK4a and Ki-67 in cervical neoplasia and its correlations with cofactors. Methods: The study involved 69 patients with and without cervical neoplasia who underwent colposcopic directed biopsy. On each patient, two samples were taken; the first was used for immunohistochemistry and the second for molecular testing, using HPV16and18 genotyping Real-Time PCR Kit. Results: The study revealed the expression level of p16INK4a and Ki-67 in a descending order, from invasive squamous cell carcinoma (SCC), CIN2/3, CIN1 and non-dysplastic lesions. Correlations showed an association between the staining of p16NK4a and Ki-67 with the increase of age (OR: 1.79 (95%IC: 0.49 – 6.55), p = 0.037) and marital status (OR: 0.17 (95%IC: 0.04 – 0.68), p = 0.003). We found that the expressions of p16INK4a and Ki-67 were significantly different between invasive SCC vs non-dysplasia (OR: 44.57 (95%IC: 4.91 – 403.91), p <0.0001). The study showed significant correlation between HPV 16and18 infection with p16 INK4a and Ki-67 expression (OR: 0.13 (95%IC: 0.03 – 0.52), p <0.0001). Strong expression of p16INK4a and Ki-67 were observed in invasive squamous cell carcinoma, moderate staining was found in CIN2/3, weak staining in CIN1 and normal histology. Conclusion: Our findings indicate that p16INK4a and Ki-67 expressions associated strongly with cervical pathology. Therefore, p16/Ki-67 could be considered as a suitable biomarker for cervical cancer screening, particularly in HPV-based screening programs.     

子宫颈鳞状细胞癌中人乳头瘤病毒感染与Rb相关基因蛋白的表达及其意义

 目的　探讨子宫颈浸润性鳞状细胞癌（ISCC）中高危型人乳头瘤病毒（HPV）16／18、31／33感染与Rb相关基因蛋白p16ink4a、CyclinD1、CDK4、Rb、E2F-1和Ki-67的表达情况并分析HPV及Rb相关蛋白与ISCC临床病理参数的相关性。方法　收集73例ISCC、30例高级别鳞状上皮内病变（HSIL）、32例低级别鳞状上皮内病变（LSIL）和21例正常子宫颈鳞状上皮（NCE）。采用原位杂交法检测HPV16／18、31／33DNA的表达;免疫组织化学二步法检测上述蛋白的表达。统计分析HPV、上述蛋白及临床病理参数的关系。结果　HPV16／18、31／33在四组总体间表达差异有统计学意义（P＜0.01）,HPV16／18阳性表达与脉管内瘤栓正相关（OR＝3.875）,HPV31／33阳性表达与临床分期正相关（OR＝3.5）;p16ink4a、CyclinD1、CDK4、Rb、E2F-1和Ki-67在四组总体间差异有统计学意义（P＜0.01）。Rb与Ki-67正相关（rs=0.250）;p16ink4a阳性表达与组织分级负相关（OR＝0.942）;CDK4阳性表达与组织分级正相关（OR＝1.033）;年龄与临床分期正相关（OR＝1.063）。结论　HPV16／18、31／33感染与ISCC的发生、发展密切相关;CDK4、Ki-67可作为子宫颈病变程度的客观参考指标;Rb在ISCC中的详细作用机制还需进一步探讨。     

宫颈鳞癌HPV16感染及其与c-myc p53表达的关系

目的：探讨HPV16在宫颈鳞癌发生发展中的作用及其与c-myc、p53表达产物之间的关系。方法：采用原位杂交和免疫组化方法检测了18例慢性宫颈炎、28例CIN、4例宫颈浸润性腺鳞癌和55例宫颈浸润性鳞癌HPV16 E6 DNA及其蛋白和c-myc、p53蛋白的表达情况。结果：浸润性宫颈癌。HPV16 E6 DNA及其蛋白、p53蛋白阳性率明显高于慢性宫颈炎组，c-myc蛋白阳性率则明显低于慢性宫颈炎组。p53蛋白阳性率与HPV16 E6 DNA的检出率之间无负相关关系。结论：宫颈鳞癌的发生发展可能与HPV16 E6 DNA的检出及c-myc、p53蛋白的表达异常相关。     

The role of cyclins and cyclins inhibitors in the multistep process of HPV-associated cervical carcinoma

BACKGROUND: Human papillomavirus (HPV) types 16 and 18 are associated with cervical carcinogenesis. This is possibly achieved through an interaction between HPV oncogenic proteins and some cell cycle regulatory genes. However, the exact pathogenetic mechanisms are not well defined yet. METHODS: We investigated 110 subjects (43 invasive squamous cell carcinoma (ISCC), 38 CIN III, 11 CIN II, 18 CIN I) confirmed to be positive for HPV16 and/or 18 as well as 20 normal cervical tissue (NCT) samples for abnormal expression of cyclin D1, cyclin E, CDK4, cyclin inhibitors (p21 (waf), p27, p16 (INK4A)) and Ki-67 using immunohistochemistry and differential PCR techniques. RESULTS: There was a significant increase in the expression of Ki-67, cyclin E, CDK4, p16 (INK4A) (p=0.003, 0.001, 0.001) and a significant decrease in p27 (Kip1) from NCT to ISCC (p=0.003). There was a significant correlation between altered expression of p27 (KIP1) and p16(INK4A) (p<0.001), cyclin D1 and CDK4 (p=0.001), cyclin E and p27 (Kip1) (p=0.011) in all studied groups. In ISCC, there was significant relationship between standard clinicopathological prognostic factors and high Ki-67 index , increased cyclin D1 and cyclin E, reduced p27 (Kip1) and p21 (waf). CONCLUSION: 1) Aberrations involving p27 (KIP1), cyclin E, CDK4 and p16 (INK4A) are considered early events in HPV 16 and 18-associated cervical carcinogenesis (CINI & II), whereas cyclin D1 aberrations are late events (CINIII & ISCC) 2) Immunohistochemical tests for p16 (INK4A) and cyclin E could help in early diagnosis of cervical carcinoma 3) Only FIGO stage, cyclin D1, p27 (Kip1) and Ki-67 are independent prognostic factors that might help in predicting outcome of cervical cancer patients.     

p63、CD44v6及HPV16/18在子宫颈癌及癌前病变中的表达及意义

  目的　探讨p63、CD44v6及HPV16/18在不同子宫颈组织病变中的表达及临床病理意义。方法　制作包含有60例子宫颈癌,55例子宫颈上皮内瘤变（CIN）,30例健康人子宫颈上皮的组织芯片,采用免疫组织化学及原位杂交方法检测p63、CD44v6及HPV16／18 在145 例子宫颈病变组织中的表达情况。结果　p63、CD44v6及HPV16／18在子宫颈癌中的表达与CIN和对照组比较差别均有统计学意义（P＜0.05）;HPV16／18在CIN组随着级别增高阳性表达率升高（27.3 %,43.8 %,70.6 %）;p63主要在鳞状细胞癌中表达,在腺癌中不表达;p63阳性率与鳞状细胞癌的分级、临床分期有关;CD44v6的阳性率与肿瘤的病理分级和临床分期有关,并且淋巴结转移病例的阳性率明显高于无转移的病例（P＜0.05）。HPV16／18与p63表达程度相关（P＜0.05）,Cp值为0.49。结论　HPV16／18参与子宫颈鳞状细胞癌的发生和发展,p63可能作为癌基因参与了HPV16／18的致瘤过程,并可作为向鳞状上皮分化的恶性肿瘤的标记之一;CD44v6可以作为判断子宫颈癌远处转移指标之一。     

Methylation Status of P16Ink4a in Human Papillomavirus-Associated Cancer of Oral Cavity and Oropharynx in Northeastern Thailand

Background: Over-expression of p16INK4a protein is a biomarker for human papillomavirus (HPV)-associated cervical cancer. However, absence of p16INK4a protein expression in HPV-associated cancer of the oral cavity and oropharynx has been reported. Among a number of possible reasons for this is methylation, which is frequently noted in the promoter region of p16INK4a and is associated with silencing of the gene and disease severity. Methods: We investigated the relationships between p16INK4a protein expression, HPV infection and methylation status of the p16INK4a promoter in cancers of the oral cavity and oropharynx. Fifty-three formalin-fixed paraffin-embedded (FFPE) cancer tissue samples from the oral cavity (49 cases) and oropharynx (4 cases) were studied. P16INK4a protein expression was determined using immunohistochemical staining (IHC). Additional oral tissues lacking squamous intraepithelial lesions (SILs), and cervical tissues with high-level SILs, were used as negative and positive controls, respectively. High-risk HPV infection was detected using HPV E6/E7 mRNA in situ hybridization. Methylation status of the p16INK4a promoter was investigated using sodium bisulfite treatment and methylation-specific PCR (MS-PCR).Results: HPV infection was found in 40.8% (20/49) and 50.0% (2/4) of oral cavity and oropharynx cancers, respectively. Promoter methylation of p16INK4a occurred in 73.6 % of all cases and differed significantly in frequency between HPV-positive (90.9%, 20/22) and HPV-negative (61.3%, 19/31) samples. Expression of p16INK4a was found in 35.8% (19/53) and commonly detected in samples with p16INK4a unmethylation (79.5%). Interestingly, the silencing of p16INK4a (64.2%, 34/53) was significantly associated with methylation status (91.2%, 31/34), especially in HPV-infected samples in which the p16INK4a promoter was methylated (52.9%, 18/34). Conclusions: This result demonstrated high frequency of p16INK4a promoter methylation status in HPV-associated HNSCC subsets that could influence the silent p16INK4a expression and might promote disease severity.     

Diagnostic value of p16INK4A,Ki‐67, and human papillomavirus L1 capsid protein immunochemical staining on cell blocks from residual liquid‐based gynecologic cytology specimens

BACKGROUND:

This study was conducted to evaluate the reliability and role of cell block preparations in the diagnosis of neoplastic and preneoplastic lesions of the cervix and to improve the value of cell block preparations in diagnosing and predicting the prognosis of cervical lesions through immunostaining of p16INK4A (p16), Ki‐67, and human papillomavirus (HPV) L1 capsid protein (HPV L1).

METHODS:

In total, 138 specimens were diagnosed on liquid‐based cytology (LBC) and cell block preparations, and 63 specimens were subjected subsequently to tissue follow‐up and immunostaining for p16, Ki‐67, and HPV L1 on cell block sections.

RESULTS:

In 42 specimens that were diagnosed as low‐grade squamous intraepithelial lesion, high‐grade squamous intraepithelial lesion (HSIL), and squamous cell carcinoma (SCC) on cell blocks, 38 specimens (90.5%) were confirmed by histopathologic reports, and there was slightly better than 81.6% agreement between LBC and tissue follow‐up. Immunointensity and cells that were positive for p16 were enhanced according to increased pathologic grade and differed statistically between cervical intraepithelial neoplasia 1 (CIN‐1) and CIN‐2/CIN‐3 as well as SCC. The positive rates of HPV L1 decreased gradually according to the severity of cervical neoplasia, and HPV L1/p16 expression patterns were related to the severity of cervical lesions.

CONCLUSIONS:

The cell block preparation technique was complementary to LBC, and the authors concluded that the application of LBC combined with cell block preparations may improve the diagnostic accuracy of cytology. Immunostaining for p16 and Ki‐67 on cell block preparations can help to improve the diagnostic accuracy of HSIL and SCC. A combined expression pattern of p16 and HPV L1 may serve as a valuable index for predicting prognosis and follow‐up of cervical dysplastic lesions. Cancer (Cancer Cytopathol) 2010. © 2010 American Cancer Society.     

Induction of p16 during immortalization by HPV 16 and 18 and not during malignant transformation.

The p16 (MTS1) tumour-suppressor gene is a cyclin-dependent kinase (cdk) inhibitor that decelerates the cell cycle by inactivating the cdks that phosphorylate the retinoblastoma tumour-suppressor gene (Rb) protein (pRb). In cervical cancers, pRb is inactivated by the HPV E7 oncoprotein or by mutations. The hypothesis of earlier reports was that the disruption of the p16/cdk-cyclin/Rb cascade is essential for malignant cervical transformation/carcinogenesis. We previously established in vitro model systems of cervical cancer representing four steps of oncogenic progression initiated by the two most common oncogenic HPVs in ectocervical and endocervical epithelial cells. This report used these systems to investigate the role of p16 in cervical cancers. A dramatic enhancement of the p16 RNA level was observed after immortalization by HPV 16 or 18. Furthermore, the p16 protein was newly observed following immortalization. However, no further changes were found for RNA or protein levels after serum selection or malignant transformation. For three cervical carcinoma cell lines, similar high levels of p16 expression were seen. Point mutations or homozygous deletions of p16 were not observed in the in vitro systems or in clinical specimens. These results suggest that the inactivation of the p16/cdk-cyclin/Rb cascade does not occur during malignant transformation but occurs during the immortalization by HPV in HPV-harbouring premalignant lesions, the in situ equivalent of immortalized cells. Also suggested is that p16 has no role in the specific malignant transformation step from immortal premalignant lesions during the carcinogenesis of HPV-initiated cervical cancers.     

HPV 16 in multiple neoplastic lesions in women with CIN III

Paraffin embedded material of multiple primary cancers and other hyperplastic tumours from fifteen patients were analyzed by PCR and in situ hybridization for the presence of HPV DNA in the lesions. All patients had also high grade cervical intraepithelial dysplasia (CIN III) and breast carcinomas and were selected from a previous study enrolling 46 women with CIN III and breast carcinomas. HPV 16 was detected by PCR in 8/15 patients (53%), with eleven HPV 16 positive tumours. HPV 16 was detected in two malignant melanomas, one basal cell carcinoma, one squamous cell carcinoma of the vulva, one Bowen disease of the vulva, two high grade vaginal intraepithelial neoplasias, one cancer corporis uteri, one bronchial carcinoma and two lymphomas. Three cases, two high grade vaginal intraepithelial neoplasia and a squamous cell carcinoma of the vulva, were also reported to be positive by in situ hybridization. 5/8 patients (63%) with HPV 16 positive second cancers had also HPV 16 positive breast carcinomas. All fifteen patients with second cancers after CIN III had HPV 16 positive CIN III lesions; 53% of the patients had also a familial cancer history. We assume that HPV 16 may be involved in the development of different second cancers in women with HPV 16 positive CIN III.     

Introduction of p16<Superscript>INK4a</Superscript> as a surrogate biomarker for HPV in women with invasive cervical cancer in Sudan

Background

Cervical cancer is the fourth most common cancer in women worldwide with highest incidence reported in Eastern Africa in 2012. The primary goal of this study was to study the expression of p16^INK4a in squamous cell carcinoma (SCC) of the cervix by immunohistochemistry (IHC) and determine relation with clinico-pathological parameters. This study further explored the correlation of p16^INK4a immunostaining with another proliferation marker, Ki-67 and to study if human papillomavirus (HPV) IHC can be used as a marker for detection of virus in high-grade dysplasia.

Methods

A total of 90 samples, diagnosed for cervical cancer, were included in the study. Fixed Paraffin Embedded (FFPE) tissue sections were stained with anti-p16^INK4a, anti-Ki-67 and anti-HPV antibodies using automated immunohistochemistry platform (ASLink 48-DAKO).

Results

Immunohistochemical protein expression of p16^INK4a positivity was found to be highest in SCC (92.2%, n = 71) than other HPV tumors (76.9%, n = 10). The majority of cases (97.4%) were p16^INK4a positive in the age group 41–60 years. In addition, a statistically significant difference between p16^INK4a and HPV was observed among total cervical tumor cases and SCC cases.

Conclusions

As expected staining of invasive cervical cancer with anti-HPV showed rare positivity because HPV heralds active infection in dysplastic lesions and not of frank cervical carcinoma. In contrast, anti-p16^INK4a IHC results showed positive correlation in SCC and other cervical tumors.

     

p73 is over-expressed in vulval cancer principally as the Delta 2 isoform.

p73 was studied in squamous cancers and precursor lesions of the vulva. Over-expression of p73 occurred commonly in both human papillomavirus (HPV)-positive and -negative squamous cell cancers (SCC) and high-grade premalignant lesions. Whereas expression in normal vulval epithelium was detected only in the basal and supra-basal layers, expression in neoplastic epithelium increased with grade of neoplasia, being maximal at both protein and RNA levels in SCC. p73 Delta 2 was the principal over-expressed isoform in the majority of cases of vulval SCC and often the sole form expressed in SCC. Over-expression of p73 was associated with expression of HPV-encoded E7 or with hypermethylation or mutation of p16(INK4a) in HPV-negative cases. There was a close correlation between expression of p73 and p14(ARF) in cancers with loss of p53 function. The frequent over-expression of p73 Delta 2 in neoplastic but not normal vulval epithelium, and its co-ordinate deregulation with other E2F-1 responsive genes suggests a role in the oncogenic process.     

The clinical impact of using p16INK4a immunochemistry in cervical histopathology and cytology: An update of recent developments

Cervical cancer screening test performance has been hampered by either lack of sensitivity of Pap cytology or lack of specificity of Human Papillomavirus (HPV) testing. This uncertainty can lead to unnecessary referral and treatment, which is disturbing for patients and increases costs for health care providers. The identification of p16^INK4a as a marker for neoplastic transformation of cervical squamous epithelial cells by HPVs allows the identification of HPV‐transformed cells in histopathology or cytopathology specimens. Diagnostic studies have demonstrated that the use of p16^INK4a immunohistochemistry substantially improves the reproducibility and diagnostic accuracy of histopathologic diagnoses. p16^INK4a cytology has substantially higher sensitivity for detection of cervical precancer in comparison to conventional Pap tests. Compared to HPV DNA tests, immunochemical detection of p16^INK4a‐stained cells demonstrates a significantly improved specificity with remarkably good sensitivity. About 15 years after the initial observation that p16^INK4a is overexpressed in HPV‐transformed cells we review the accumulated clinical evidence suggesting that p16^INK4a can serve as a useful biomarker in the routine diagnostic work up of patients with HPV infections and associated lesions of the female anogenital tract.     

p16INK4a在宫颈液基细胞学辅助筛查中的标记意义

目的 评价p16INK4a在宫颈液基细胞学检查中的标记意义.方法 收集74例宫颈外口和颈管的脱落细胞标本,分别进行液基细胞学检测和p16INK4a免疫细胞化学染色,并应用杂交捕获二代法检测高危人乳头瘤病毒(HR-HPV)感染.结果 74例标本中,细胞学诊断未见癌细胞或癌前病变细胞(阴性)10例,意义不明的不典型鳞状细胞(ASC-US)15例,鳞状上皮内低度病变(LSIL)28例,不除外上皮内高度病变的不典型鳞状细胞(ASC-H)5例,鳞状上皮内高度病变(HSIL)11例,鳞状细胞癌(SCC)5例.各级别病变中,HR-HPV阳性者分别为1、4、3、9、7和5例,p16INK4a免疫细胞化学染色阳性者分别为2、5、3、8、9和5例.随着宫颈病变级别的上升,HR-HPV和p16INK4a免疫细胞化学染色阳性率均增高.结论 p16INK4a免疫细胞化学染色增强了对不典型细胞的区分能力,可以提高宫颈癌筛查的准确性.     

Relationship among human papillomavirus infection, p16(INK4a), p53 and NF-κB activation in penile cancer from northern Thailand

Human papillomavirus (HPV) E6 and E7 oncoproteins are essential factors for HPV oncogenesis. These E6 and E7 gene products play a central role in the induction of malignant transformation by interacting with several cellular regulatory proteins such as p16(INK4a), p53 and nuclear factor κB (NF-κB). In the present study, conducted in northern Thailand, HPV-DNA was detected in penile cancer cases using an in situ hybridization procedure and p16(INK4a), p53 and NF-κB were detected by immunohistochemistry. Using the cell cycle regulatory proteins p16(INK4a) (61.5%) and p53 (71.8%), it was found that of the 51 cases, 39 (76.5%) were HPV-DNA-positive in penile cancer. On the other hand, 25% p16(INK4a) and 75% p53, respectively, were found in HPV-negative cases. Prevalence of HPV infection (76.5%) was shown in penile cancer cases in northern Thailand. No difference was found between HPV-positive and HPV-negative cases with respect to the presence of the cell cycle regulatory protein p53. On the other hand, p16(INK4a) was found to be different between HPV-positive and HPV-negative cases. Inactivation of tumor suppressor genes, such as p16(INK4a) and p53, to genetic instability, cell immortalization, accumulation of mutations and cancer formation, with or without HPV and irrespective of HPV infection, is therefore suggested. Of the 39 HPV-positive cases, 35 (89.7%) were NF-κB-positive in the nucleus, 29 (74.4%) in the cytoplasm and 37 (94.9%) in the nucleus and/or cytoplasm. NF-κB was detected in 4 (33.3%) of the 12 HPV-negative cases. Therefore, we propose that penile cancer cases with HPV infection are more likely to activate NF-κB than those without HPV infection.     

P16蛋白在子宫颈上皮内瘤变中表达意义与高危型HPV感染的相关性分析

  目的  研究P16蛋白在宫颈上皮内瘤变（CIN）中表达的意义, 探讨其与高危型人类乳头状瘤病毒（HPV）感染的相关性, 以期用P16蛋白的表达预测CIN进展。  方法  收集大连大学附属医院2009年1月至2011年5月宫颈活检及手术切除标本137例, 免疫组织化学方法检测P16蛋白的表达并评分, HC2方法检测高危型HPV-DNA, 并对数据进行分析。  结果  P16蛋白表达在慢性子宫颈炎伴鳞状上皮化生中均阴性（0/40）, CINⅠ阳性90.91%（20/22）, CINⅡ阳性为95.00%（19/20）, CINⅢ阳性为100.00%（25/25）, 浸润性鳞癌阳性为100.00%（30/30）。在慢性子宫颈炎伴鳞化中高危型HPV阳性1例, CINⅠ12例, CINⅡ14例, CINⅢ22例, 浸润性鳞癌29例。CIN中感染高危型HPV的病例, P16蛋白均呈阳性表达。  结论  P16蛋白可作为区分子宫颈癌及癌前病变与良性反应性增生的标记物, 其表达的分层现象能够很好的反映出CIN的分级, P16蛋白阳性表达的评分有助于区分出有高危发展倾向的CIN。