Cell Cycle Regulators p105, p107, Rb2/p130, E2F4, p21CIP1/WAF1, Cyclin A in Predicting Cervical Intraepithelial Neoplasia, High-Risk Human Papillomavirus Infections and Their Outcome in Women Screened in Three New Independent States of the Former Soviet Union

Cyclin A1 shows age-related expression in benign tonsils, HPV16-dependent overexpression in HNSCC and predicts lower recurrence rate in HNSCC independently of HPV16

Background

Promoter methylation of the tumor suppressor gene Cyclin A1 could be associated with Human Papillomavirus 16 (HPV16) induced Head and Neck Squamous Cell Carcinoma (HNSCC) and Cervical Carcinoma. There is disagreement about the impact of this epigenetic event on protein expression of Cyclin A1 in malignant and non-malignant tissue and there hardly exists any information about possible relationships between Cyclin A1 expression and clinicopathological characteristics in HNSCC.

Methods

We analyzed protein expression of Cyclin A1 in 81 HNSCC and 74 benign tonsils by immunohistochemistry and correlated it to Cyclin A1 methylation status, presence of HPV16 infection and other clinicopathological characteristics.

Results

Overexpression of Cyclin A1 was more present in HNSCC than in tonsils (p < 0.001). In both entities, HNSCC and benign tonsils, expression of Cyclin A1 significantly correlated with the expression of Cyclin-dependent kinase-inhibitor p16 (p = 0.000672 and 0.00495). In tonsils, expression of Cyclin A1 was inversely proportional to age (p = 0.00000396), and further correlated with expression of tumor suppressor gene p53 (p = 0.000228). In HNSCC Cyclin A1 expression was associated with the presence of HPV16 DNA (p = 0.0014) and a lower recurrence rate in univariate and multivariate analysis (p = 0.002 and 0.013). Neither in HNSCC nor in tonsils Cyclin A1 expression correlated with promoter methylation.

Conclusions

Cyclin A1 is an important cell cycle regulator with age-related increased expression in tonsils of children. HPV16 induces overexpression of Cyclin A1 in HNSCC despite promoter methylation. Overexpression of Cyclin A1 predicts a lower recurrence rate in HNSCC independently of HPV16.

Smoking habit, immune suppression, oral contraceptive use, and hormone replacement therapy use and cervical carcinogenesis: a review of the literature

High-risk human papillomaviruses (HPVs) are involved in the etiopathogenesis of cervical intraepithelial neoplasia (CIN) and cervical cancer. After taking HPV into account, smoking habit appears to be the most significant environmental risk factor, and the risk of this malignancy increases significantly with intensity and duration of smoking. Women with human immunodeficiency virus (HIV) infection experience a higher incidence of CIN and invasive cervical cancer. Among HIV+ women, the highly active antiretroviral therapy increases the regression rate of CIN, but the majority of these lesions do not regress to normal. As far as oral contraceptives (OCs), a systematic review of 28 studies found that, compared with never pill users, the relative risk (RR) of cervical cancer increased with increasing duration of OC use. The results were similar for squamous cell carcinoma and adenocarcinoma, and the RRs decreased after pill discontinuation. However, by weighing risks and benefits, the World Health Organization does not recommend any change in OC practice. There is no correlation between hormone replacement therapy and cervical cancer. Experimental data have shown that estradiol and progesterone can modulate the host immune response to HPV16. Prophylactic vaccination in conjunction with cervical screening is the best prevention strategy for cervical cancer.

FTS (fused toes homolog) a novel oncoprotein involved in uterine cervical carcinogenesis and a potential diagnostic marker for cervical cancer

The high incidence and fatality rate of uterine cervical cancer warrant effective diagnostic and therapeutic target identification for this disease. Here, we have found a novel oncoprotein FTS (Fused Toes Homolog), which is involved in cervical cancer pathogenesis. Immunohistochemical analysis of human cervical biopsy samples revealed that the expression of FTS is absent in normal cervical epithelium but progressively overexpressed in human cervical intraneoplastic lesions (CIN-I to CIN-III), this characteristic phenomenon put this protein, a potential diagnostic marker for the screening of early neoplastic changes of cervix. Using FTS-specific small hairpin RNA (shRNA) in cervical cancer cells, we determined a specific role for FTS protein in, cervical neoplasia. Targeted stable knock down of FTS in HeLa cells led to the growth inhibition, cell-cycle arrest, and apoptosis with concurrent increase in p21 protein. FTS effectively represses the p21 mRNA expression in dual luciferase assay which indicates that p21 is transcriptionally regulated by this oncoprotein which in turn affect the regular cell-cycle process and its components. Consistent with this we found a reciprocal association between these proteins in early cervical neoplastic tissues. These data unraveled the involvement of new oncoprotein FTS in cervical cancer which plays a central role in carcinogenesis. Targeted inhibition of FTS lead to the shutdown of key elemental characteristics of cervical cancer and could lead to an effective therapeutic strategy for cervical cancer.

Promoter methylation of cyclin A1 is associated with human papillomavirus 16 induced head and neck squamous cell carcinoma independently of p53 mutation

Aberrant promoter methylation of specific genes and infection with human papillomavirus 16 (HPV16) are known risk factors for the development of Head and Neck Squamous Cell Carcinoma (HNSCC). Little knowledge exists on the interaction of HPV16 infection and promoter methylation in HNSCC. The promoter methylation status of 12 genes (TIMP3, CDH1, CDKN2A, DAPK1, transcription factor 21 (TCF21), CD44, MLH1, MGMT, RASSF1, cyclin A1 (CCNA1), LARS2, and CEBPA) was evaluated by methylation-specific polymerase chain reaction in 55 primary HNSCC and 31 controls. The results were correlated with HPV16 status and clinicopathological characteristics. CCNA1 and p53 protein expression were additionally determined by immunohistochemistry and compared with p53 mutation status. Methylation of DAPK1 (P = 0.043), CCNA1 (P = 0.016) and TCF21 (P = 0.0005) was significantly more present in HNSCC than in controls. The genes TIMP3 (P = 0.018) and CCNA1 (P = 0.015) showed higher methylation frequency in HPV16 positive HNSCC compared to HPV16 negative tumors. CCNA1 methylation did not correlate with CCNA1 protein expression and p53 mutation, respectively. Methylation of TCF21 was associated with higher age (P = 0.044) and nicotine abuse (P = 0.035). Methylation of CCNA1 was significantly more present in females (P = 0.003). Methylation of TCF21 and CCNA1 are important risk factors for HNSCC development. CCNA1 methylation may play a crucial role in HPV16-induced carcinogenesis of HNSCC independently of p53.

Up-regulation of lipocalin 2 is associated with high-risk human papillomavirus and grade of cervical lesion at baseline but does not predict outcomes of infections or incident cervical intraepithelial neoplasia

Our objective was to assess whether neutrophil gelatinase-associated lipocalin (NGAL)/lipocalin 2 (LCN2) expression in cervical human papillomavirus (HPV) lesions has implications on the outcome of HPV infections or disease progression. Cervical biopsy specimens from 225 women in the Latin American Screening study were analyzed for NGAL/LCN2 expression using immunohistochemical analysis, to assess associations with cervical intraepithelial neoplasia (CIN) grade, high-risk HPV, and in predicting outcomes of high-risk (HR)-HPV infections. Expression of NGAL/LCN2 increased with lesion grade (odds ratio [OR], 3.86; 95% confidence interval [CI], 1.53-9.71; P = .001). Up-regulation was also related to HR-HPV detection (OR, 2.21; 95% CI, 1.15-4.24; P = .016) and showed a linear relationship to HR-HPV load (P = .002). NGAL/LCN2 expression was of no value in predicting the outcomes of HR-HPV infections or the surrogate end points (incident CIN 1+ and CIN 2+) of progressive disease. Because the SV40 large T antigen is a powerful up-regulator of this lipocalin, up-regulation of NGAL/LCN2 in CIN is probably induced by HR-HPV E6 oncoprotein, most likely by eliminating its normal transcription repression exerted by wild-type p53.

Up-regulation of 14-3-3sigma (Stratifin) is associated with high-grade CIN and high-risk human papillomavirus (HPV) at baseline but does not predict outcomes of HR-HPV infections or incident CIN in the LAMS study

To assess whether the potentially high-risk (HR) human papillomavirus (HPV)-related up-regulation of 14-3-3sigma (stratifin) has implications in the outcome of HPV infections or cervical intraepithelial neoplasia (CIN) lesions, cervical biopsy specimens from 225 women in the Latin American Screening Study were analyzed for 14-3-3sigma expression using immunohistochemical analysis. We assessed its associations with CIN grade and HR HPV at baseline and value in predicting outcomes of HR-HPV infections and the development of incident CIN 1+ and CIN 2+. Expression of 14-3-3sigma increased in parallel with the lesion grade. Up-regulation was also significantly related to HR-HPV detection (P = .004; odds ratio, 2.71; 95% confidence interval, 1.37-5.35) and showed a linear relationship to HR-HPV loads (P = .003). 14-3-3sigma expression was of no value in predicting the outcomes (incident, persistent, clearance) of HR-HPV infections or incident CIN 1+ and CIN 2+. 14-3-3sigma is not inactivated in cervical carcinoma and CIN but is up-regulated on transition from CIN 2 to CIN 3. Its normal functions in controlling G(1)/S and G(2)/M checkpoints are being bypassed by HR HPV.

Differential expression of cell cycle regulators in HCV-infection and related hepatocellular carcinoma

AIM

To investigate cell cycle proteins in chronic hepatitis C virus infection in order to analyze their role in the process of hepatocyte transformation and to characterize their prognostic properties.

METHODS

Subjects of the current study included 50 cases of chronic hepatitis C (CHC) without cirrhosis, 30 cases of CHC with liver cirrhosis (LC), and 30 cases of hepatitis C-related hepatocellular carcinoma (HCC) admitted to the Department of Hepato-Gastroenterology, Theodor Bilharz Research Institute (TBRI), Giza, Egypt. Fifteen wedge liver biopsies, taken during laparoscopic cholecystectomy, were also included as normal controls. Laboratory investigations including urine and stool analysis, liver function tests and prothrombin concentration; serologic markers for viral hepatitis and ultrasonography were done for all cases of the study together with immunohistochemical analysis using primary antibodies against Cyclin D1, Cyclin E, p21, p27 and Rb/p105 proteins.

RESULTS

Normal wedge liver biopsies didn't express Cyclin E or Rb/p105 immunostaining but show positive staining for Cyclin D1, p21 and p27. Cyclin D1 expressed nuclear staining that was sequentially increased from CHC to LC (P < 0.01) to HCC (P < 0.001) cases; meanwhile, Cyclin E revealed nuclear positivity only in the case of HCCs patients that was directly correlated to Rb/p105 immuno-reactivity. The expression of p21 and p27 was significantly increased in CHC and LC cases compared to normal controls and HCCs with no significant difference between well- and poorly-differentiated tumors. p21 showed only a nuclear pattern of staining, while, p27 presented with either cytoplasmic and/or nuclear reactivity in all studied cases. Correlation analysis revealed a direct relation between Cyclin D1 and p21 in CHC cases (P < 0.001), between Cyclin D1 and Cyclin E in HCCs (P < 0.01); however, an inverse relationship was detected between Cyclin D1 and p21 or p27 (P < 0.001) and between p21 and Rb/p105 (P < 0.05) in HCCs.

CONCLUSION

Upregulation of Cyclin D1 in CHC plays a vital role in the development and differentiation of HCC; while, Cyclin E may be a useful marker formonitoring tumor behavior. p21 and p27 can be used as predictive markers for HCC. Furthermore, higher expression of Rb/p105 as well as inverse relation with p21 and histologic grades suggests its important role in hepatic carcinogenesis.

Up-regulation of plasminogen activator inhibitor-2 is associated with high-risk HPV and grade of cervical lesion at baseline but does not predict outcomes of high-risk HPV infections or incident CIN

Protease inhibitor serpin-B2 (plasminogen activator inhibitor-2 [PAI-2]) protects pRb from degradation in human papillomavirus (HPV)-18+ HeLa cells. Our objective was to assess whether the pRb-mediated HPV-suppressive effect of PAI-2 in cancer cell lines has implications in the outcome of HPV infections. Cervical biopsy specimens from 225 women were analyzed for PAI-2 expression to assess its value as a predictor of cervical intraepithelial neoplasia (CIN) grade, high-risk (HR) HPV at baseline, outcomes of HR-HPV infections, and the development of incident CIN. PAI-2 expression increased in parallel with lesion grade. Nuclear PAI-2 expression was significantly related to HR-HPV detection and had a linear relationship with HR-HPV load. PAI-2 expression was of no value in predicting the outcomes of HR-HPV infections. The same was true for PAI-2 as a predictor of surrogate end points (incident CIN 1+, CIN 2+) of progressive disease. PAI-2 expression is up-regulated on transition from CIN 2 to CIN 3. The HR-HPV suppressive effects of PAI-2 were not related to more favorable outcomes of HR-HPV infections or lower risk of disease progression to CIN.

Immunosuppressive cytokine Interleukin-10 (IL-10) is up-regulated in high-grade CIN but not associated with high-risk human papillomavirus (HPV) at baseline, outcomes of HR-HPV infections or incident CIN in the LAMS cohort

Bypassing the local immunological defense reactions in the cervix is one of the prerequisites for human papillomaviruses (HPV) infections to progress to intraepithelial neoplasia (CIN). The role of potent immunosuppressive cytokines, e.g., interleukin-10 (IL-10), depressing these local virus-specific immunological responses is incompletely studied. To assess, whether IL-10 expression in cervical HPV lesions has any implications in the outcome of HPV infections or disease progression to CIN. Baseline cervical biopsies from 225 women of the LAMS study sub-cohort were analyzed for IL-10 expression using immunohistochemistry, to assess its associations with CIN grade, and high-risk HPV (HR-HPV) at baseline, as well as in predicting outcomes of HR-HPV infections, and development of incident CIN1+ and CIN2+ in this longitudinal setting. Expression of IL-10 in cervical lesions was up-regulated most often in high-grade CIN, and IL-10 over-expression retained its value as independent predictor of CIN2+ (odds ratio (OR) = 4.92) and CIN3+ (OR = 7.51) also in multivariate model, including HR-HPV and several known covariates of IL-10 expression. Up-regulation was not related to HR-HPV detection, and showed no relationship to HR-HPV viral loads. Using longitudinal predictive indicators (SE, SP, PPV, NPV), IL-10 expression was of no value in predicting (1) the outcomes of HR-HPV infections, or (2) the surrogate endpoints (incident CIN1+, CIN2+) of progressive disease. IL-10 over-expression (along with HR-HPV) was one of the independent covariates of CIN2/3. This immunosuppressive cytokine might play an important role in creating a microenvironment that favors progressive cervical disease and immune evasion by HR-HPV.

pRb2/p130 protein expression and RBL2 mutation analysis in Burkitt lymphoma from Uganda

Background

The members of the retinoblastoma protein family, pRb, p107 and pRb2 (p130), are central players in controlling the cell cycle. Whereas disturbed function of pRb is commonly seen in human cancers, it is still an open question whether pRb2 is involved in tumorigenic processes. However, altered subcellular localization of pRb2 and mutations in the pRb2-encoding gene RBL2 have been described for some tumours, including Burkitt lymphomas (BL).

Methods

We retrieved 51 biopsy specimens of endemic BL cases from Uganda. The expression of pRb2 was determined by immunohistochemistry. Exons 19-22 of the RBL2 gene, the region known to contain a nuclear localization signal, were screened for mutations by PCR amplification and direct DNA sequencing.

Results

Nearly all of our cases (84.0%) were positive for pRb2 protein expression although this protein is a marker for growth arrest and Burkitt lymphoma is characterized by a high proliferation rate. Of the positive cases, 73.8% were scored as expressing the protein at a high level. Subcellular pRb2 localization was predominantly nuclear and no cases with expression restricted to the cytoplasm were observed. We did not detect any RBL2 mutations in the part of the gene that encodes the C-terminal end of the protein.

Conclusion

The majority of endemic BL cases from Uganda express pRb2, but somatic RBL2 mutations affecting the protein's nuclear localization signal appear to be rare.