Promotion effect of FOXCUT as a microRNA sponge for miR-24-3p on progression in triple-negative breast cancer through the p38 MAPK signaling pathway.

BACKGROUND: Triple-negative breast cancer (TNBC) is a type of highly invasive breast cancer with a poor prognosis. According to new research, long noncoding RNAs (lncRNAs) play a significant role in the progression of cancer. Although the role of lncRNAs in breast cancer has been well reported, few studies have focused on TNBC. This study aimed to explore the biological function and clinical significance of forkhead box C1 promoter upstream transcript (FOXCUT) in triple-negative breast cancer. METHODS: Based on a bioinformatic analysis of the cancer genome atlas (TCGA) database, we detected that the lncRNA FOXCUT was overexpressed in TNBC tissues, which was further validated in an external cohort of tissues from the General Surgery Department of the First Affiliated Hospital of Nanjing Medical University. The functions of FOXCUT in proliferation, migration, and invasion were detected in vitro or in vivo. Luciferase assays and RNA immunoprecipitation (RIP) were performed to reveal that FOXCUT acted as a competitive endogenous RNA (ceRNA) for the microRNA miR-24-3p and consequently inhibited the degradation of p38. RESULTS: lncRNA FOXCUT was markedly highly expressed in breast cancer, which was associated with poor prognosis in some cases. Knockdown of FOXCUT significantly inhibited cancer growth and metastasis in vitro or in vivo. Mechanistically, FOXCUT competitively bounded to miR-24-3p to prevent the degradation of p38, which might act as an oncogene in breast cancer. CONCLUSION: Collectively, this research revealed a novel FOXCUT/miR-24-3p/p38 axis that affected breast cancer progression and suggested that the lncRNA FOXCUT could be a diagnostic marker and therapeutic target for breast cancer.

Deubiquitinase USP19 modulates apoptotic calcium release and endoplasmic reticulum stress by deubiquitinating BAG6 in triple negative breast cancer.

BACKGROUND: Triple-negative breast cancer (TNBC), a heterogeneous subtype of breast cancer (BC), had poor prognosis. Endoplasmic reticulum (ER) stress was responsible for cellular processes and played a crucial role in the cell function. ER stress is a complex and dynamic process that can induce abnormal apoptosis and death. However, the underlying mechanism of ER stress involved in TNBC is not well defined. METHODS: We identified ubiquitin-specific protease 19 (USP19) as a TNBC negative regulator for further investigation. The effects of USP19 on BC proliferation were assessed in vitro using proliferation test and cell-cycle assays, while the effects in vivo were examined using a mouse tumorigenicity model. Through in vitro flow cytometric analyses and in vivo TUNEL assays, cell apoptosis was assessed. Proteomics was used to examine the proteins that interact with USP19. RESULTS: Multiple in vitro and in vivo tests showed that USP19 decreases TNBC cell growth while increasing apoptosis. Then, we demonstrated that USP19 interacts with deubiquitinates and subsequently stabilises family molecular chaperone regulator 6 (BAG6). BAG6 can boost B-cell lymphoma 2 (BCL2) ubiquitination and degradation, thereby raising ER calcium (Ca2+ ) levels and causing ER stress. We also found that the N6 -methyladenosine (m6 A) "writer" methyltransferase-like 14 (METTL14) increased global m6 A modification. CONCLUSIONS: Our study reveals that USP19 elevates the intracellular Ca2+ concentration to alter ER stress via regulation of BAG6 and BCL2 stability and may be a viable therapeutic target for TNBC therapy.

LHX2 Is a Potential Biomarker and Associated with Immune Infiltration in Breast Cancer.

Worldwide, breast cancer is the most common malignancy. LHX2, a member of the LIM homeobox gene family and a transcription factor, plays a crucial role in numerous tumors, but the function of LHX2 in breast cancer progression remains unknown. In this study, we show that LHX2 is upregulated in breast cancer tissues and positively correlated with breast cancer progression. Meanwhile, the clinical characteristics of breast cancer and LHX2 expression showed a strong correlation. GSEA showed that a high LHX2 expression may activate the T-cell activation pathway, PI3K/AKT/mTOR signaling pathway, and apoptosis pathway. Moreover, ssGSEA showed that Th1 cells and Th2 cells had a positive correlation with LHX2 expression in breast cancer. Experiments showed that LHX2 promotes the proliferation, colony formation, migration, and invasion of breast cancer cells. Immunohistochemistry and immunofluorescence assays helped to analyze LHX2-associated immune infiltration in breast cancer. A Western blot assay proved that LHX2 activated the PI3K/AKT/mTOR pathway and the apoptosis pathway. A TUNEL assay confirmed that LHX2 inhibited apoptosis. Taken together, LHX2 plays a vital role in breast cancer's progression and prognosis and could be an immune infiltration biomarker for breast cancer, and LHX2 activates the PI3K/AKT/mTOR pathway and apoptosis pathway in breast cancer.

An immunogenic cell death-related classification predicts response to immunotherapy and prognosis in triple-negative breast cancer.

OBJECTIVE: Immunogenic cell death (ICD) of tumor cells is characterized by the induction of adaptive and innate immune responses, which in turn activates the immune surveillance and improves the efficacy of immunotherapy. In this study, we aimed to investigate the effect of ICD on the prognosis and the efficacy of immunotherapy in patients with triple-negative breast cancer (TNBC). METHODS: TNBC samples from The Cancer Genome Atlas-Breast Cancer (TCGA-BRCA) dataset were divided into two subtypes (ICD-high and ICD-low) based on the ICD status by using the consensus clustering method, and their genomic landscape and immune landscape were delineated. Furthermore, we established an ICD-related prognostic model to predict the efficacy of immunotherapy and the survival of TNBC. RESULTS: Our study showed that a poor prognosis of TNBC was associated with ICD-high subtype, while a favorable outcome was associated with ICD-low subtype. The immune landscape profiling results revealed that ICD-high subtype presented an immune-hot phenotype, whereas ICD-low subtype was associated with an immune-cold phenotype. Furthermore, our prognostic model predicted that the high-risk score group had a poor overall survival (OS), which was consistent with the actual data in the Gene Expression Omnibus (GEO) dataset. We also used tumor immune dysfunction and exclusion (TIDE) to determine the predictive significance of our ICD risk signature in immunotherapy efficacy, and found that ICD high-risk group had the highest response rate to immunotherapy in the immunotherapy response group. CONCLUSION: Our results reveal a correlation between ICD status and alterations in the tumor immune microenvironment in patients with TNBC. This finding might help guide clinicians in immunotherapy application for TNBC patients.

Polymorphism rs4787951 in IL-4R contributes to the increased risk of renal cell carcinoma in a Chinese population.

OBJECTIVE: Interleukins are important molecules involved in tumor formation. In this study, the association between renal cell carcinoma (RCC) risk and single nucleotide polymorphisms (SNPs) on IL-4/IL-13/IL-4R was assessed. METHODS: We recruited 620/623 cases/controls and conducted a case-control study. Five tagSNPs (i.e., IL-4R rs8832, IL-4R rs4787951, IL-13 rs1881457, IL-13 rs2066960 and IL-13 rs2069744) were selected. Odds ratios (ORs) with their 95% confidence intervals (CIs) were obtained to appraise the association between SNPs and RCC susceptibility. Luciferase report assay and EMSA were conducted to investigate whether SNPs could affect binding affinity of transcription factors to target genes. RESULTS: IL-4R rs4787951T>C was significantly associated with RCC susceptibility. Individuals carrying CC genotypes had a significant increment in RCC risk compared with TT genotype carriers (adjusted OR = 1.57, 95% CI = 1.07-2.28, P = 0.020). By stratified analyses, more pronounced association was found in the female, diabetic or without smoking, drinking and hypertension group. Besides, SNP rs4787951 could influence the binding affinity of IL-4R to transcription factors. Sequence surrounding allele T was prone to bind transcription factor NFATc. CONCLUSIONS: This study revealed that IL-4R rs4787951T>C was associated with susceptibility of RCC and could be a predictive biomarker for RCC risk.