Background: Epigenetic gene silencing is one of the major causes of carcinogenesis. Its widespread occurrence in cancer genome could inactivate many cellular pathways including DNA repair, cell cycle control, apoptosis, cell adherence, and detoxification. The abnormal promoter methylation might be a potential molecular marker for cancer management. Methods: For rapid identification of potential targets for aberrant methylation in gynecological cancers, methylation status of the CpG islands of 34 genes was determined using pooled DNA approach and methylation-specific PCR. Pooled DNA mixture from each cancer type (50 cervical cancers, 50 endometrial cancers and 50 ovarian cancers) was made to form three test samples. The corresponding normal DNA from the patients of each cancer type was also pooled to form the other three control samples. Methylated alleles detected in tumors, but not in normal controls, were indicative of aberrant methylation in tumors. Having identified potential markers, frequencies of methylation were further analyzed in individual samples. Markers identified are used to correlate with clinico-pathological data of tumors using χ² or Fisher's exact test. Results: APC and p16 were hypermethylated across the three cancers. MINT31 and PTEN were hypermethylated in cervical and ovarian cancers. Specific methylation was found in cervical cancer (including CDH1, DAPK, MGMT and MINT2), endometrial cancer (CASP8, CDH13, hMLH1 and p73), and ovarian cancer (BRCA1, p14, p15, RIZ1 and TMS1). The frequencies of occurrence of hypermethylation in 4 candidate genes in individual samples of each cancer type (DAPK, MGMT, p16 and PTEN in 127 cervical cancers; APC, CDH13, hMLH1 and p16 in 60 endometrial cancers; and BRCA1, p14, p16 and PTEN in 49 ovarian cancers) were examined for further confirmation. Incidence varied among different genes and in different cancer types ranging from the lowest 8.2% (PTEN in ovarian cancer) to the highest 56.7% (DAPK in cervical cancer). Aberrant methylation for some genes (BRCA1, DAPK, hMLH1, MGMT, p14, p16, and PTEN) was also associated with clinico-pathological data. Conclusion: Thus, differential methylation profiles occur in the three types of gynecologic cancer. Detection of methylation for critical loci is potentially useful as epigenetic markers in tumor classification. More studies using a much larger sample size are needed to define the potential role of DNA methylation as marker for cancer management.

The study aims to present the effect of PIK3CA E542K and E545K mutations on glucose metabolism and proliferation and identify their underlying mechanisms in cervical cancer. The maximum standard uptake value (SUV_max) of tumors was detected by¹⁸F-FDG PET/CT scan. In vitro, glycolysis analysis, extracellular acidification rate analysis, and ATP production were used to evaluate the impact of PIK3CA E542K and E545K mutations on glucose metabolism. The expression level of key glycolytic enzymes was evaluated by western blotting and immunohistochemical staining in cervical cancer cells and tumor tissues, respectively. Immunofluorescence analysis was used to observe the nuclear translocation of β-catenin. The target gene of β-catenin was analyzed by using luciferase reporter system. The glucose metabolic ability of the xenograft models was assessed by SUV_max from microPET/CT scanning. Cervical cancer patients with mutant PIK3CA (E542K and E545K) exhibited a higher SUV_max value than those with wild-type PIK3CA (P = 0.037), which was confirmed in xenograft models. In vitro, enhanced glucose metabolism and proliferation was observed in SiHa and MS751 cells with mutant PIK3CA. The mRNA and protein expression of key glycolytic enzymes was increased. AKT/GSK3β/β-catenin signaling was highly activated in SiHa and MS751 cells with mutant PIK3CA. Knocking down β-catenin expression decreased glucose uptake and lactate production. In addition, the nuclear accumulation of β-catenin was found in SiHa cells and tumors with mutant PIK3CA. Furthermore, β-catenin downregulated the expression of SIRT3 via suppressing the activity of the SIRT3 promotor, and the reduced glucose uptake and lactate production due to the downregulation of β-catenin can be reversed by the transfection of SIRT3 siRNA in SiHa cells with mutant PIK3CA. The negative correlation between β-catenin and SIRT3 was further confirmed in cervical cancer tissues. These findings provide evidence that the PI3K E542K and E545K/β-catenin/SIRT3 signaling axis regulates glucose metabolism and proliferation in cervical cancers with PIK3CA mutations, suggesting therapeutic targets in the treatment of cervical cancers. FUSCC 050432–4-1212B. Registered 24 December 2012 (retrospectively registered).

Mutations in 16 targetable oncogenic genes were examined using reverse transcription polymerase chain reaction (RT-PCR) and direct sequencing in 285 Chinese cervical cancers. Their clinicopathological relevance and prognostic significance was assessed. Ninety-two nonsynonymous somatic mutations were identified in 29.8% of the cancers. The mutation rates were as follows: PIK3CA (12.3%), KRAS (5.3%), HER2 (4.2%), FGFR3-TACC3 fusions (3.9%), PTEN (2.8%), FGFR2 (1.8%), FGFR3 (0.7%), NRAS (0.7%), HRAS (0.4%) and EGFR (0.4%). No mutations were detected in AKT1 or BRAF, and the fusions FGFR1-TACC1, EML4-ALK, CCDC6-RET and KIF5B-RET were not found in any of the cancers. RTK and RAS mutations were more common in non-squamous carcinomas than in squamous carcinomas (P=0.043 and P=0.042, respectively). RAS mutations were more common in young patients (<45 years) (13.7% vs. 7.7%, P=0.027). RTK mutations tended to be more common in young patients, whereas PIK3CA/PTEN/AKT mutations tended to be more common in old patients. RAS mutations were significantly associated with disease relapse. To our knowledge, this is the first comprehensive analysis of major targetable oncogenic mutations in a large cohort of cervical cancer cases. Our data reveal that a considerable proportion of patients with cervical cancers harbor known druggable mutations and might benefit from targeted therapy.

Small cell neuroendocrine carcinoma of the cervix (SCNEC) is a lethal malignancy and little treatment progress has been made for decades. We sought to map its genetic profiles, and identify whether SCNEC harbor mutations and potential targets for therapeutic interventions. Primary tumor tissue and blood samples were obtained from 51 patients with SCNEC. The next-generation sequencing was carried out to detect mutations of 520 cancer-related genes, including the entire exon regions of 312 genes and the hotspot mutation regions of 208 genes. Quantitative multiplex PCR was performed for the detection of seven high-risk HPV types. Of the 51 detected patients, 92.16% were positive for HPV 18. Ninety-eight percent of cases harbored genetic alterations. Two cases were observed with hypermutated phenotype and determined as MSI-H/dMMR. Genetic mutations were clustering in RTK/RAS(42.86%), PI3K-AKT(38.78%), p53 pathway(22.45%) and MYC family(20.41%). Mutations in genes involved in the p53 pathway indicate a poorer prognosis (3-year OS, 33.5% vs 59.9%, p = 0.031). A total of seven patients harboring mutations in homogeneous recombination repair (HRR) genes were reported. In addition, IRS2 and SOX2 were amplified in 14.9% and 6.12% of SCNEC patients, respectively. SCNEC is specifically associated with HPV 18 infection. Its genetic alterations are characterized by a combined feature of high-risk HPV driven events and mutations observed in common neuroendocrine carcinoma. We identified several targetable mutated genes, including KRAS, PIK3CA, IRS2, SOX2, and HRR genes, indicating the potential efficacy of target therapies in these patients. MSI-H/dMMR individuals may benefit from checkpoint blockade therapies.

Background: Alterations in peripheral blood lymphocytes in cervical cancer have been reported, although conflicting views exist. The present study investigated the distributions of lymphocyte subsets in tumor tissue and peripheral blood samples from cervical cancer patients and precancerous lesion patients, and evaluated the correlations of lymphocyte subsets with clinicopathological and prognostic variables. Methods: A total of 44 patients with stage IB1-IIA2 cervical cancer and 13 precancerous lesion patients were included. Lymphocytes were collected from the tumor tissue and the peripheral blood, and isolated by Lymphoprep density gradient centrifugation. The percentages of lymphocyte subsets were quantified by flow cytometry analysis, and the differences between lymphocyte subsets in the tumor tissue and peripheral blood were compared by SPSS. In addition, the relationships between lymphocyte subsets and clinicopathological and prognostic variables were analyzed. Results: Our results revealed that the amount of total T lymphocytes, CD8+ T cells, granulocytes, pDCs, CD16+ monocytes and CD56^high NK cells were significantly higher in the tumor tissue than in the peripheral blood in the cervical cancer patients, while those of CD4+ T cells, CD4+/CD8+ cell ratio, rdT cells, BDCA1+ mDCs, total monocytes, CD14+ monocytes, NK cells and CD56^low NK cells exhibited the opposite trend (p < 0.05). The levels of total pDCs and BDCA1+ mDCs in the peripheral blood were significantly lower in the cervical cancer patients than in the precancerous lesion patients, while the proportion of CD16+ monocytes was elevated (p < 0.05). In addition, some lymphocyte subsets, especially CD4+ cells and CD8+ cells, and the CD4+/CD8+ cell ratio were closely associated with clinicopathological and prognostic parameters. Conclusions: These results suggested that distinct alterations in infiltrating lymphocyte subsets occurred in the tumor and were associated with clinicopathological and prognostic parameters. Systemic impairment of the immune system may occur in the antitumor response of cervical cancer patients.

The aim of this study was to evaluate the clinicopathological and prognostic relevance of PIK3CA mutations in Chinese patients with surgically resected cervical cancer. PIK3CA mutations were screened in 771 cervical cancer specimens using reverse transcription polymerase chain reaction and Sanger sequencing. In total, 13.6% (105 of 771) of patients harbored non-synonymous PIK3CA mutations. Patients harboring PIK3CA mutations were older than patients with wild-type PIK3CA (mean age: 50.7 years vs. 47.0 years, P < 0.01). PIK3CA mutations were more commonly observed in postmenopausal patients than in premenopausal patients (19.6% vs. 10.2%, P < 0.01). PIK3CA mutations were more common in squamous cell carcinomas than in non-squamous cell tumors (15.3% vs 7.3%, of P < 0.01). The 3-year relapse-free survival was 90.2% for PIK3CA mutant patients and 80.9% for PIK3CA wild-type patients (P = 0.03). PIK3CA mutation was confirmed as an independent predictor for better treatment outcome in the multivariate analyses (HR = 0.54, 95% CI: 0.29–0.99, P = 0.048). PIK3CA mutations were significantly associated with less distant metastases (mutant-type: 8/105, wild-type: 98/666, p = 0.048). Thus, patients with mutant PIK3CA had distinct characteristics in age, menopausal status and histological subtype and have better treatment outcome and less distant metastasis after surgery-based multimodal therapy.