Frequent PIK3CA mutations in eutopic endometrium of patients with ovarian clear cell carcinoma

Somatic mutation of targeted sequencing identifies risk stratification in advanced ovarian clear cell carcinoma

BACKGROUND

Ovarian clear cell carcinoma (OCCC) is a unique subtype of epithelial ovarian cancer. Advanced OCCC display a poor prognosis. Therefore, we aimed to make risk stratification for precise medicine.

METHODS

We performed a large next generation sequencing (NGS) gene panel on 44 patients with OCCC in FIGO stage II-IV. Then, by machine learning algorithms, including extreme gradient boosting (XGBoost), random survival forest (RSF), and Cox regression, we screened for feature genes associated with prognosis and constructed a 5-gene panel for risk stratification. The prediction efficacy of the 5-gene panel was compared with FIGO stage and residual disease by receiver operating characteristic curve and decision curve analysis.

RESULTS

The feature mutated genes related to prognosis, selected by machine learning algorithms, include MUC16, ATM, NOTCH3, KMT2A, and CTNNA1. The 5-gene panel can effectively distinguish the prognosis, as well as platinum response, of advanced OCCC in both internal and external cohorts, with the predictive capability superior to FIGO stage and residual disease.

CONCLUSIONS

Mutations in genes, including MUC16, ATM, NOTCH3, KMT2A, and CTNNA1, were associated with the poor prognosis of advanced OCCC. The risk stratification according to these genes demonstrated acceptable prediction power of prognosis and platinum response, suggesting the potential to be a novel target for precision medicine.

The Nectin family ligands, PVRL2 and PVR, in cancer immunology and immunotherapy

In recent years, immunotherapy has emerged as a crucial component of cancer treatment. However, its efficacy remains limited across various cancer types, highlighting unmet needs. Poliovirus receptor-related 2 (PVRL2) and Poliovirus receptor (PVR) are members of the Nectin and Nectin-like Molecules family, known for their role as cell-cell adhesion molecules. With the development of immunotherapy, their involvement in tumor immune mechanisms as immune checkpoint factors has garnered significant attention. PVRL2 and PVR are predominantly expressed on tumor cells and antigen-presenting cells, binding to PVRIG and TIGIT, respectively, which are primarily found on T and NK cells, thereby suppressing antitumor immunity. Notably, gynecological cancers such as ovarian and endometrial cancers exhibit high expression levels of PVRL2 and PVR, with similar trends observed in various other solid and hematologic tumors. Targeting these immune checkpoint pathways offers a promising therapeutic avenue, potentially in combination with existing treatments. However, the immunomodulatory mechanism involving these bindings, known as the DNAM-1 axis, is complex, underscoring the importance of understanding it for developing novel therapies. This article comprehensively reviews the immunomodulatory mechanisms centered on PVRL2 and PVR, elucidating their implications for various cancer types.

The "Road" to Malignant Transformation from Endometriosis to Endometriosis-Associated Ovarian Cancers (EAOCs): An mTOR-Centred Review

Ovarian cancer is an umbrella term covering a number of distinct subtypes. Endometrioid and clear-cell ovarian carcinoma are endometriosis-associated ovarian cancers (EAOCs) frequently arising from ectopic endometrium in the ovary. The mechanistic target of rapamycin (mTOR) is a crucial regulator of cellular homeostasis and is dysregulated in both endometriosis and endometriosis-associated ovarian cancer, potentially favouring carcinogenesis across a spectrum from benign disease with cancer-like characteristics, through an atypical phase, to frank malignancy. In this review, we focus on mTOR dysregulation in endometriosis and EAOCs, investigating cancer driver gene mutations and their potential interaction with the mTOR pathway. Additionally, we explore the complex pathogenesis of transformation, considering environmental, hormonal, and epigenetic factors. We then discuss postmenopausal endometriosis pathogenesis and propensity for malignant transformation. Finally, we summarize the current advancements in mTOR-targeted therapeutics for endometriosis and EAOCs.

The role of peroxisome proliferator-activated receptors in endometriosis

Endometriosis constitutes the most common cause of chronic pelvic pain in female patients and is associated with infertility. Although there is no known cause for the disease, it is a heritable condition that is determined by numerous genetic, epigenetic, and environmental aspects. Peroxisome proliferator-activated receptors (PPARs) represent nuclear receptor proteins that control gene expression. By using the MEDLINE and LIVIVO databases we conducted a literature review in order to look into the role of PPARs in the endometriosis pathophysiology and succeeded in revealing 36 pertinent publications between 2001 and 2022. In regards to PPAR expression in endometriosis, PPARγ seems to represent the most studied PPAR isoform in endometriosis and to influence various pathways involved in the disease onset and progression. It's interesting to note that diverse treatment agents targeting the PPAR system have been identified as innovative, effective therapeutic alternatives in the context of endometriosis treatment. In conclusion, PPARs appear to contribute an important role in both endometriosis pathophysiology and therapy.

Synchronous ovarian and uterine mesonephric-like carcinoma that potentially arose from endometrioid adenofibroma: A case report

Mesonephric-like carcinoma histologically resembles mesonephric adenocarcinoma (MA) of the cervix. MA arises from mesonephric duct remnants. However, the origin of mesonephric-like carcinoma is not extensively studied because of its rarity. Here, we present a case of synchronous ovarian and uterine mesonephric-like carcinoma that potentially arose from endometrioid adenofibroma. A 69-year-old woman presented with an abdominal mass with no genital bleeding. She underwent simple total abdominal hysterectomy and bilateral adnexal resection. Histological and immunohistochemical analyses were consistent with mesonephric-like carcinoma involving both ovaries and the uterus. Endometrioid adenofibroma was present in both ovaries, while adenomyosis was observed in the uterus. The glandular duct of the endometrioid adenofibroma in the right ovary had areas suggestive of precursor lesions of mesonephric-like carcinoma. All tumors exhibited the KRAS G12D mutation. These findings suggest that the origin of the mesonephric-like carcinoma was the Müllerian duct, and that the ovarian and uterine tumors were monoclonal.

Review the progression of ovarian clear cell carcinoma from the perspective of genomics and epigenomics

Ovarian clear cell carcinoma (OCCC) is a rare subtype of epithelial ovarian cancer with unique molecular characteristics, specific biological and clinical behavior, poor prognosis and high resistance to chemotherapy. Pushed by the development of genome-wide technologies, our knowledge about the molecular features of OCCC has been considerably advanced. Numerous studies are emerging as groundbreaking, and many of them are promising treatment strategies. In this article, we reviewed studies about the genomics and epigenetics of OCCC, including gene mutation, copy number variations, DNA methylation and histone modifications.

New Understanding of Diagnosis, Treatment and Prevention of Endometriosis

For 100 years, pelvic endometriosis has been considered to originate from the implantation of endometrial cells following retrograde menstruation or metaplasia. Since some observations, such as the clonal aspect, the biochemical variability of lesions and endometriosis in women without endometrium, the genetic-epigenetic (G-E) theory describes that endometriosis only begins after a series of cumulative G-E cellular changes. This explains that the endometriotic may originate from any pluripotent cell apart from the endometrium, that 'endometrium-like cells' can harbour important G-E differences, and that the risk is higher in predisposed women with more inherited incidents. A consequence is a high risk after puberty which decreases progressively thereafter. Considering a 10-year delay between initiation and performing a laparoscopy, this was observed in the United Arab Emirates, Belgium, France and USA. The subsequent growth varies with the G-E changes and the environment but is self-limiting probably because of the immunologic reaction and fibrosis. That each lesion has a different set of G-E incidents explains the variability of pain and the response to hormonal treatment. New lesions may develop, but recurrences after surgical excision are rare. The fibrosis around endometriosis belongs to the body and does not need to be removed. This suggests conservative excision or minimal bowel without safety margins and superficial treatment of ovarian endometriosis. This G-E concept also suggests prevention by decreasing oxidative stress from retrograde menstruation or the peritoneal microbiome. This suggests the prevention of vaginal infections and changes in the gastrointestinal microbiota through food intake and exercise. In conclusion, a higher risk of initiating endometriosis during adolescence was observed in UAE, France, Belgium and USA. This new understanding and the limited growth opens perspectives for earlier diagnosis and better treatment.

PIK3CA mutation affects the proliferation of colorectal cancer cells through the PI3K-MEK/PDK1-GPT2 pathway

The phosphatidylinositol‑3‑kinase catalytic subunit α (PIK3CA) gene is mutated in numerous human cancers. This mutation promotes the proliferation of tumor cells; however, the underlying mechanism is still not clear. In the present study, it was revealed that the PIK3CA mutation in colorectal cancer (CRC) HCT116 (MUT) rendered the cells more dependent on glutamine by regulating the glutamic‑pyruvate transaminase 2 (GPT2). The dependence of glutamine increased the proliferation of cells in a normal environment and resistance to a suboptimal environment. Further study revealed that the mutated PIK3CA could regulate GPT2 expression not only through signal transduction molecule 3‑phosphoinositide‑dependent kinase (PDK1) but also through mitogen‑activated protein kinase (MEK) molecules. In HCT116 cells, MEK inhibitor treatment could reduce the expression of GPT2 signaling molecules, thereby inhibiting the proliferation of CRC cells. A new signal transduction pathway, the PI3K/MEK/GPT2 pathway was identified. Based on these findings, MEK and PDK1 inhibitors were combined to inhibit the aforementioned pathway. It was revealed that the combined application of MEK and PDK1 inhibitors could promisingly inhibit the proliferation of MUT compared with the application of PI3K inhibitors, PDK1 inhibitors, or MEK inhibitors alone. In vivo, MEK inhibitors alone and combined inhibitors had stronger tumor‑suppressing effects. There was no significant difference between the PDK1‑inhibitor group and normal group in vivo. Thus, these results indicated that mutated PI3K affected GPT2 mediated by the MEK/PDK1 dual pathway, and that the PI3K/MEK/GPT2 pathway was more important in vivo. Inhibiting MEK and PDK1 concurrently could effectively inhibit the proliferation of CRC cells. Targeting the MEK and PDK1 signaling pathway may provide a novel strategy for the treatment of PIK3CA‑mutated CRC.