Treatment and outcomes in undifferentiated and dedifferentiated endometrial carcinoma

ZNF554 Inhibits Endometrial Cancer Progression via Regulating RBM5 and Inactivating WNT/β-Catenin Signaling Pathway

OBJECTIVE

Uterine corpus endometrial carcinoma (UCEC), a kind of gynecologic malignancy, poses a significant risk to women's health. The precise mechanism underlying the development of UCEC remains elusive. Zinc finger protein 554 (ZNF554), a member of the Krüppel-associated box domain zinc finger protein superfamily, was reported to be dysregulated in various illnesses, including malignant tumors. This study aimed to examine the involvement of ZNF554 in the development of UCEC.

METHODS

The expression of ZNF554 in UCEC tissues and cell lines were examined by qRT-PCR and Western blot assay. Cells with stably overexpressed or knocked-down ZNF554 were established through lentivirus infection. CCK-8, wound healing, and Transwell invasion assays were employed to assess cell proliferation, migration, and invasion. Propidium iodide (PI) staining combined with fluorescence-activated cell sorting (FACS) flow cytometer was utilized to detect cell cycle distribution. qRT-PCR and Western blotting were conducted to examine relative mRNA and protein levels. Chromatin immunoprecipitation assay and luciferase reporter assay were used to explore the regulatory role of ZNF554 in RNA binding motif 5 (RBM5).

RESULTS

The expression of ZNF554 was found to be reduced in both UCEC samples and cell lines. Decreased expression of ZNF554 was associated with higher tumor stage, decreased overall survival, and reduced disease-free survival in UCEC. ZNF554 overexpression suppressed cell proliferation, migration, and invasion, while also inducing cell cycle arrest. In contrast, a decrease in ZNF554 expression resulted in the opposite effect. Mechanistically, ZNF554 transcriptionally regulated RBM5, leading to the deactivation of the Wingless (WNT)/β-catenin signaling pathway. Moreover, the findings from rescue studies demonstrated that the inhibition of RBM5 negated the impact of ZNF554 overexpression on β-catenin and p-glycogen synthase kinase-3β (p-GSK-3β). Similarly, the deliberate activation of RBM5 reduced the increase in β-catenin and p-GSK-3β caused by the suppression of ZNF554. In vitro experiments showed that ZNF554 overexpression-induced decreases in cell proliferation and migration were counteracted by RBM5 knockdown. Additionally, when RBM5 was overexpressed, it hindered the improvements in cell proliferation and migration caused by reducing the ZNF554 levels.

CONCLUSION

ZNF554 functions as a tumor suppressor in UCEC. Furthermore, ZNF554 regulates UCEC progression through the RBM5/WNT/β-catenin signaling pathway. ZNF554 shows a promise as both a prognostic biomarker and a therapeutic target for UCEC.

Role of radiotherapy in the management of rare gynaecological cancers

There are a large number of gynaecological cancers with rare histologies, for which the available data are limited and usually retrospective. Because of their rarity and poor prognosis, the management of these cancers must be centralized in expert centres, for both histological diagnosis and treatment. With the exception of sarcomas, most endometrial or cervical cancers with rare histologies respond to the same radiation treatment modalities than cancers with more common histologies, although there are some specificities regarding treatments such as neuroendocrine carcinomas (chemotherapy with platinum and etoposide, major role of surgery). For localized or locally advanced ovarian cancer, external beam radiotherapy has a role in the management of hypercalcaemic small cell carcinoma of the ovary. This article summarizes the current role of external beam radiotherapy and brachytherapy in the management of cancers of the uterine cervix, uterine corpus and ovaries, with rare or very rare histologies, and with localized or locally advanced stages.

Beyond Serous: Treatment Options for Rare Endometrial Cancers

OPINION STATEMENT

Rare endometrial cancers are high-grade, aggressive malignancies which are often diagnosed at an advanced stage, and account for disproportionately more deaths than their more common low-grade counterparts. Standard of care includes a combination of surgery, radiation, and chemotherapy. Surgery consists of complete hysterectomy, and more recent evidence supports replacing a full lymphadenectomy with sentinel node mapping. Paclitaxel and carboplatin remain the mainstays of chemotherapy, while current studies incorporating immunotherapy will inform future practice. Whether and how to incorporate radiation remains controversial, and certain histologic subtypes, such as carcinosarcomas, may benefit from radiation more than others. Owing to their relative rarity, it is difficult to conduct clinical trials in this patient population, which has hindered the development of effective therapies for rare malignancies. Molecular profiling has offered insight into the pathogenesis of rare endometrial cancers, providing actionable targets for personalized therapy.

Rare Subtype of Endometrial Cancer: Undifferentiated/Dedifferentiated Endometrial Carcinoma, from Genetic Aspects to Clinical Practice

Endometrial cancer (EC) is one of the most common gynecologic cancers worldwide. There were 417,367 newly diagnosed cases and 97,370 deaths due to this disease worldwide in 2020. The incidence rates have increased over time, especially in countries with rapid socioeconomic transitions, and EC has been the most prevalent gynecologic malignancy in Taiwan since 2012. The new EC molecular classifications of The Cancer Genome Atlas (TCGA) Research Network include clear-cell carcinoma, serous carcinoma, and carcinosarcoma, while undifferentiated/dedifferentiated EC (UDEC) is not mentioned, and most previous clinical trials for EC have not included UDEC. UDEC is rare, has an aggressive growth pattern, tends to be diagnosed at an advanced stage, and is resistant to conventional chemotherapy. In this review, case series or case reports on the clinical features and genomic/epigenetic and expression profiles on UDEC data are summarized in order to identify potential molecular targets for current and future research.