Up-regulation of expression and lack of 5' CpG island hypermethylation of p16 INK4a in HPV-positive cervical carcinomas

BACKGROUND: High risk type human papilloma viruses (HR-HPV) induce carcinomas of the uterine cervix by expressing viral oncogenes E6 and E7. Oncogene E7 of HR-HPV disrupts the pRb/E2F interaction, which negatively regulates the S phase entry. Expression of tumor suppressor p16(ink4a )drastically increases in majority of HR-HPV associated carcinomas due to removal of pRb repression. The p16(ink4a )overexpression is an indicator of an aberrant expression of viral oncogenes and may serve as a marker for early diagnostic of cervical cancer. On the other hand, in 25–57% of cervical carcinomas hypermethylation of the p16 INK4a promoter has been demonstrated using a methylation-specific PCR, MSP. To evaluate a potential usage of the p16 INK4a 5' CpG island hypermethylation as an indicator of tumor cell along with p16(ink4a )overexpression, we analyzed the methylation status of p16 INK4a in cervical carcinomas METHODS: Methylation status of p16 INK4a was analyzed by MSP and by bisulfite-modified DNA sequencing. The expression of p16(ink4a )was analyzed by RT-PCR and by immunohistochemical technique. RESULTS: The extensive methylation within p16 INK4a 5' CpG island was not detected either in 13 primary cervical carcinomas or in 5 cancer cell lines by bisulfite-modified DNA sequencing (including those that were positive by MSP in our hands). The number and distribution of rare partially methylated CpG sites did not differ considerably in tumors and adjacent normal tissues. The levels of the p16 INK4a mRNA were increased in carcinomas compared to the normal tissues independently of the number of partially methylated CpGs within 5'CpG island. The transcriptional activation of p16 INK4a was accompanied by p16(ink4a )cytoplasmic immunoreactivity in the majority of tumor cells and presence of a varied number of the p16 positive nuclei in different tumors. CONCLUSION: Hypermethylaion of the p16INK4a 5' CpG island is not a frequent event in HR-HPV-positive cervical carcinomas and cannot be an effective marker of cancer cells with up-regulated expression of p16(ink4a). Our data confirm other previous studies claiming specific p16INK4a up-regulation in the majority of cervical carcinomas at both the protein and mRNA levels. Cytoplasmic accumulation of p16(ink4a )is a feature of cervical carcinomas

Immunohistochemical factors of prognosis of immunotherapy for metastatic melanoma: А prospective and retrospective study

Introduction. Anti-PD-1 immunotherapy (IT) is becoming the standard treatment for patients with metastatic melanoma. However, immune checkpoint inhibitors are only effective in a fraction of patients, and studies examining biological markers and their correlation with clinical efficacy are insufficient to draw unambiguous conclusions. Aim. To improve the outcomes of the first-line therapy for disseminated melanoma based on identifying clinical and immunohistochemical predictors of IT efficacy. Materials and methods. Data from 130 patients who were treated with immune checkpoint inhibitors (nivolumab or prolgolimab) in the first-line therapy for disseminated melanoma between 2017 and 2024 were analyzed. Results. Improvement was observed in 24 patients (18.4%): complete response in 18 patients (13.8%), partial response in 6 (4.6%), and stabilization in 71 (54.6%) patients. Progression was reported in 31 (24%) patients. Death occurred in 4 (3%) cases during IT with prolgolimab due to disease progression. The two-year disease-free survival (DFS) during IT was 53% (95% confidence interval [CI] 42–67), p=0.63; the median 2-year overall survival was not reached. In the immunohistochemical study, 47 (63.5%) patients had a predominance of tumor infiltration with CD8 lymphocytes over CD4, regardless of the IT type: 2-year DFS 82% (95% CI 70–96) vs 13% (95% CI 2.7–64) in the absence of CD8 predominance over CD4, p=0.0001; the median DFS was not reached in patients with the predominance of CD8 lymphocytes tumor infiltration over CD4 compared to the other group – 7.6 months in the absence of this feature (95% CI 5.8–0), p=0.001. The peritumoral location of the immune lymphoid infiltrate was observed in all 74 (100%) patients, and the intratumoral location was less common (52 patients, 70%). In the presence of both periand intratumoral location of the immune infiltrate, the 2-year DFS was 83% (95% CI 70–98) compared to the group of patients in whom no intratumoral location was detected – 5.5% (95% CI 0.8–36), p0.0001. The expression of programmed cell death ligand 1 (PD-L1) level 10% was observed in 47 (63.5%) patients. With this level of PD-L1 expression, the one-year DFS was 91% (95% CI 83–100) compared to 29% (95% CI 15–57) with a lower level of PD-L1 expression, p0.0001; the median DFS is reached, and in the group 2, DFS was only 6.6 months. In the case of PD-L110%, the 2-year DFS was high at 78% (95% CI 63–100), p0.0001. Conclusion. Based on the study's results, it can be assumed that immunohistochemical characteristics such as a PD-L1 expression level 10%, the simultaneous presence of periand intratumoral lymphoid tumor infiltration, and the predominance of CD8 over CD4 can be considered predictors of IT efficacy with nivolumab and prolgolimab