High amplification of PVT1 and MYC predict favorable prognosis in early ovarian carcinoma

Regulation of 4-HNE via SMARCA4 Is Associated with Worse Clinical Outcomes in Hepatocellular Carcinoma

Accumulation of 4-hydroxynonenal (4-HNE), a marker of lipid peroxidation, has various favorable and unfavorable effects on cancer cells; however, the clinicopathological significance of its accumulation in hepatocellular carcinoma (HCC) and its metabolic pathway remain unknown. This study analyzed 4-HNE accumulation and its clinicopathological significance in HCC. Of the 221 cases, 160 showed relatively low accumulation of 4-HNE in HCC tissues, which was an independent prognostic predictor. No correlation was found between 4-HNE accumulation and the expression of the antioxidant enzymes glutathione peroxidase 4, ferroptosis suppressor protein 1, and guanosine triphosphate cyclohydrolase 1. Therefore, we hypothesized that 4-HNE metabolism is up-regulated in HCC. A database search was focused on the transcriptional regulation of aldo-keto reductases, alcohol dehydrogenases, and glutathione-S-transferases, which are the metabolic enzymes of 4-HNE, and seven candidate transcription factor genes were selected. Among the candidate genes, the knockdown of SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a, member 4 (SMARCA4) increased 4-HNE accumulation. Immunohistochemical analysis revealed an inverse correlation between 4-HNE accumulation and SMARCA4 expression. These results suggest that SMARCA4 regulates 4-HNE metabolism in HCC. Therefore, targeting SMARCA4 provides a basis for a new therapeutic strategy for HCC via 4-HNE accumulation and increased cytotoxicity.

Identification of hub necroptosis-related lncRNAs for prognosis prediction of esophageal carcinoma

Necroptosis is a newly identified programmed cell death associated with the biological process of various cancers, including esophageal carcinoma (ESCA). Meanwhile, the dysregulation of long non-coding RNAs (lncRNAs) is greatly implicated in ESCA progression and necroptosis regulation. However, the lncRNAs involved in regulating necroptosis in ESCA are still unclear. In this study, we aim to explore the expression profile of necroptosis-related lncRNAs (NRLs), and evaluate their roles in ESCA prognosis and treatment. In the present study, 198 differentially expressed NRLs were identified between the ESCA and adjacent normal tissues through screening the data extracted from the Cancer Genome Atlas (TCGA) database. And, a prognostic panel consisting of 6 NRLs was constructed using the LASSO algorithm and multivariate Cox regression analysis. The ESCA patients with high risks had a markedly reduced survival time and higher mortality prevalence. Moreover, C-index of 6 NRLs-panel was superior to 48 published prognostic models based on lncRNAs or mRNAs for ESCA. There were significant differences between the high-risk and low-risk groups in tumor-related pathways, genetic mutations, and drug sensitivity responses. In vitro analysis revealed that inhibition of PVT1 impeded the proliferation, migration, and colony formation of ESCA cells, increased the expressions of p-RIP1 and p-MLKL and promoted necroptosis. By contrast, PVT1 overexpression resulted in a decrease in necroptotic cell death events, thus promoting tumor progression. Collectively, the established 6-NRLs panel was a promising biomarker for the prognostic prediction of ESCA. Moreover, our current findings provided potential targets for individualized therapy for ESCA patients.

Deregulated Metabolic Pathways in Ovarian Cancer: Cause and Consequence

Ovarian cancers are tumors that originate from the different cells of the ovary and account for almost 4% of all the cancers in women globally. More than 30 types of tumors have been identified based on the cellular origins. Epithelial ovarian cancer (EOC) is the most common and lethal type of ovarian cancer which can be further divided into high-grade serous, low-grade serous, endometrioid, clear cell, and mucinous carcinoma. Ovarian carcinogenesis has been long attributed to endometriosis which is a chronic inflammation of the reproductive tract leading to progressive accumulation of mutations. Due to the advent of multi-omics datasets, the consequences of somatic mutations and their role in altered tumor metabolism has been well elucidated. Several oncogenes and tumor suppressor genes have been implicated in the progression of ovarian cancer. In this review, we highlight the genetic alterations undergone by the key oncogenes and tumor suppressor genes responsible for the development of ovarian cancer. We also summarize the role of these oncogenes and tumor suppressor genes and their association with a deregulated network of fatty acid, glycolysis, tricarboxylic acid and amino acid metabolism in ovarian cancers. Identification of genomic and metabolic circuits will be useful in clinical stratification of patients with complex etiologies and in identifying drug targets for personalized therapies against cancer.

c-MYC-Driven Polyamine Metabolism in Ovarian Cancer: From Pathogenesis to Early Detection and Therapy

c-MYC and its paralogues MYCN and MYCL are among the most frequently amplified and/or overexpressed oncoproteins in ovarian cancer. c-MYC plays a key role in promoting ovarian cancer initiation and progression. The polyamine pathway is a bona fide target of c-MYC signaling, and polyamine metabolism is strongly intertwined with ovarian malignancy. Targeting of the polyamine pathway via small molecule inhibitors has garnered considerable attention as a therapeutic strategy for ovarian cancer. Herein, we discuss the involvement of c-MYC signaling and that of its paralogues in promoting ovarian cancer tumorigenesis. We highlight the potential of targeting c-MYC-driven polyamine metabolism for the treatment of ovarian cancers and the utility of polyamine signatures in biofluids for early detection applications.

lncRNA PVT1: a novel oncogene in multiple cancers

Long noncoding RNAs are involved in epigenetic gene modification, including binding to the chromatin rearrangement complex in pre-transcriptional regulation and to gene promoters in gene expression regulation, as well as acting as microRNA sponges to control messenger RNA levels in post-transcriptional regulation. An increasing number of studies have found that long noncoding RNA plasmacytoma variant translocation 1 (PVT1) plays an important role in cancer development. In this review of a large number of studies on PVT1, we found that PVT1 is closely related to tumor onset, proliferation, invasion, epithelial–mesenchymal transformation, and apoptosis, as well as poor prognosis and radiotherapy and chemotherapy resistance in some cancers. This review comprehensively describes PVT1 expression in various cancers and presents novel approaches to the diagnosis and treatment of cancer.

Stratification of lung squamous cell carcinoma based on ferroptosis regulators: Potential for new therapeutic strategies involving ferroptosis induction

OBJECTIVES

Lung squamous cell carcinoma (LSCC) exhibits poor response to treatment compared with other lung cancer subtypes, resulting in worse prognosis. Therefore, new therapeutic strategies are required for advanced LSCC. Ferroptosis is a recently discovered nonapoptotic cell death caused by intracellular lipid peroxidation that can bring about effective cell death in cancer cells resistant to apoptosis. Hence, ferroptosis is a potential therapeutic strategy for refractory cancer.

MATERIALS AND METHODS

In this study, we performed clinicopathological and molecular analyses on tumor specimens from 270 patients with squamous cell lung cancer, focusing on the expression of glutathione peroxidase 4 (GPX4) and ferroptosis suppressor protein 1 (FSP1), which are known to be key regulators of ferroptosis, and the accumulation of 4-hydroxynoneral (4-HNE), a lipid peroxidation marker.

RESULTS

Immunohistochemistry revealed that patients with low 4-HNE accumulation and low levels of GPX4 or FSP1 had significantly worse prognoses than other patients (P = 0.001). This stratification was an independent prognostic predictor (P = 0.003). A dramatic cell death synergistic effect was observed on LSCC-derived LK-2 and EBC1 cells treated with GPX4 and FSP1 inhibitors. This effect was completely inhibited by treatment with the ferroptosis inhibitor. Notably, this was not the case in LK-2 cells treated with the apoptosis inhibitor, and in these cells, ferroptosis was induced.

CONCLUSION

Ferroptosis regulators GPX4 and FSP1 are associated with lung squamous cell cancer cancer's prognosis. We present the clinicopathological and molecular basis of novel therapeutic strategies for refractory LSCC.

LncRNA PVT1 promotes the progression of ovarian cancer by activating TGF-β pathway via miR-148a-3p/AGO1 axis

Ovarian cancer is a lethal gynaecologic malignancy with poor diagnosis and prognosis. The long non-coding RNA plasmacytoma variant translocation1 (PVT1) and argonaute 1 (AGO1) are associated with carcinogenesis and chemoresistance; however, the relationship between PVT1 and AGO1 and the downstream mechanisms in ovarian cancer remains poorly known. PVT1 and AGO1 expression was assessed through RT-qPCR and Western blotting in both human tissues and cell lines. The viability and proliferation of ovarian cancer cells were determined by CCK-8 assay and TUNEL assay in vitro and immunohistochemistry in vivo. Cell invasion and migration were investigated through transwell and wound-healing assays. The roles and mechanisms of AGO1 on cell functions were further probed via gain- and loss-of-function analysis. We reveal that PVT1 expression was significantly increased in ovarian cancer tissues which is associated with advanced FIGO stage, lymph-node metastasis, poor survival rate, and high expression of AGO1. PVT1 or AGO1 knockdown significantly reduced the cell viability and increased the cell apoptosis and inhibited ovarian tumour growth and proliferation. Furthermore, we discovered that PVT1 up-regulated the expression of AGO1 and thus regulated the transforming growth factor-β (TGF-β) pathway to promote ovarian cancer progression through sponging miR-148a-3p. Additionally, the activation of ERK1/2, smad2 and smad4 is observed to be related to the PVT1/miR-148a-3p/AGO1/TGF-β pathway-induced cascades. Taken together, the present study reveals that PVT1/miR-148a/AGO1 axis plays an important role in the progression of ovarian cancer and emphasize the potential as a target of value for ovarian cancer therapy.

c-MYC and Epithelial Ovarian Cancer

Ovarian cancer is the deadliest of gynecological malignancies with approximately 49% of women surviving 5 years after initial diagnosis. The standard of care for ovarian cancer consists of cytoreductive surgery followed by platinum-based combination chemotherapy. Unfortunately, despite initial response, platinum resistance remains a major clinical challenge. Therefore, the identification of effective biomarkers and therapeutic targets is crucial to guide therapy regimen, maximize clinical benefit, and improve patient outcome. Given the pivotal role of c-MYC deregulation in most tumor types, including ovarian cancer, assessment of c-MYC biological and clinical relevance is essential. Here, we briefly describe the frequency of c-MYC deregulation in ovarian cancer and the consequences of its targeting.