Comparative Study of Autophagy in Oxaliplatin-Sensitive and Resistant SNU-C5 Colon Cancer Cells

Excessive glutathione intake contributes to chemotherapy resistance in breast cancer: a propensity score matching analysis

BACKGROUND

We aim to explore the impact of excessive glutathione (GSH) intake on chemotherapy sensitivity in breast cancer.

METHODS

Clinicopathological data were collected from 460 breast cancer patients who underwent adjuvant chemotherapy from January 2016 to December 2019 from Zhengzhou University People's Hospital. The clinicopathological characteristics following GSH treatment were collected and compared with those in Non-GSH group after 1:2 propensity score matching (PSM). Intracellular GSH levels and the expression of antioxidant enzymes (NRF2, GPX4 and SOD1) were evaluated in tumor tissues in 51 patients receiving neoadjuvant chemotherapy.

RESULTS

The recurrence rate after adjuvant chemotherapy was significantly higher in the GSH group (n = 28, 31.8%) than that in the Non-GSH group (n = 39, 22.2%; P = 0.010). Additionally, patients in the HGSH group (high GSH intake, ≥ 16 days) exhibited an elevated recurrence rate compared to that in the LGSH group (low GSH intake, < 16 days) (n = 15 (46.8%) vs. n = 52 (22.4%); P = 0.003). Cox regression revealed that High GSH intake, Ki67 ≥ 30%, Triple negative and Lymphovascular invasion were independent risk factors of progression after adjuvant chemotherapy. Among patients receiving neoadjuvant chemotherapy, intracellular GSH levels and the expression levels of antioxidant enzymes (NRF2, GPX4 and SOD1) in the resistant patients were substantially higher (P < 0.001).

CONCLUSIONS

Excessive GSH intake may contribute to chemotherapy resistance in breast cancer, and the levels of intracellular GSH and antioxidant enzymes are elevated in resistant patients after neoadjuvant chemotherapy, indicating that the standardization of GSH intake may assist in reducing chemotherapy resistance.

Pan-cancer bioinformatics analysis of hepatic leukemia factor and further validation in colorectal cancer

Background

Hepatic leukemia factor (HLF) is associated with cancer onset, growth, and progression; however, little is known regarding its biological role in pan-cancer. In order to further evaluate the diagnostic and prognostic value of HLF in pan-cancer and colorectal cancer (CRC), we performed comprehensive bioinformatics analyses of the molecular mechanism of HLF in pan-cancer, with subsequent verification in CRC.

Methods

We downloaded data (gene expression, clinical data, follow-up duration, and immune-related data) related to 33 solid tumor types from UCSC Xena (University of California Santa Cruz cancer database, https://xena.ucsc.edu/). HLF expression was analyzed in pan-cancer, and its diagnostic efficacy, prognostic value, and correlation with pathological stage and cancer immunity were determined. We also analyzed gene alterations in HLF and biological processes involved in its regulation in pan-cancer. Using CRC data in The Cancer Genome Atlas (TCGA), we assessed correlations between HLF and CRC diagnosis, prognosis, and drug sensitivity and performed functional enrichment analyses. Moreover, we constructed an HLF-related ceRNA regulatory network. Finally, we externally validated HLF expression and diagnostic and prognostic value in CRC using Gene Expression Omnibus (GEO) database, as well as by performing in vitro experiments.

Results

HLF expression was downregulated in most tumors, and HLF showed good predictive potential for pan-cancer diagnosis and prognosis. It was closely related to the clinicopathological stages of pan-cancer. Further, HLF was associated with tumor microenvironment and immune cell infiltration in many tumors. Analyses involving cBioPortal revealed changes in HLF amplifications and mutations in most tumors. HLF was also closely associated with microsatellite instability and tumor mutational burden in pan-cancer and involved in regulating various tumor-related pathways and biological processes. In CRC, HLF expression was similarly downregulated, with implications for CRC diagnosis and prognosis. Functional enrichment analysis indicated the association of HLF with many cancer-related pathways. Further, HLF was associated with drug (e.g., oxaliplatin) sensitivity in CRC. The ceRNA regulatory network showed multigene regulation of HLF in CRC. External validation involving GEO databases and quantitative real-time polymerase chain reaction (qRT-PCR) data substantiated these findings.

Conclusions

HLF expression generally exhibited downregulation in pan-cancer, contributing to tumor occurrence and development by regulating various biological processes and affecting tumor immune characteristics. HLF was also closely related to CRC occurrence and development. We believe HLF can serve as a reliable diagnostic, prognostic, and immune biomarker for pan-cancer.

Targeting autophagy and beyond: Deconvoluting the complexity of Beclin-1 from biological function to cancer therapy

Beclin-1 is the firstly-identified mammalian protein of the autophagy machinery, which functions as a molecular scaffold for the assembly of PI3KC3 (class III phosphatidylinositol 3 kinase) complex, thus controlling autophagy induction and other cellular trafficking events. Notably, there is mounting evidence establishing the implications of Beclin-1 in diverse tumorigenesis processes, including tumor suppression and progression as well as resistance to cancer therapeutics and CSC (cancer stem-like cell) maintenance. More importantly, Beclin-1 has been confirmed as a potential target for the treatment of multiple cancers. In this review, we provide a comprehensive survey of the structure, functions, and regulations of Beclin-1, and we discuss recent advances in understanding the controversial roles of Beclin-1 in oncology. Moreover, we focus on summarizing the targeted Beclin-1-regulating strategies in cancer therapy, providing novel insights into a promising strategy for regulating Beclin-1 to improve cancer therapeutics in the future.