The Signal Transducer and Activator of Transcription 5B (STAT5B) Gene Promotes Proliferation and Drug Resistance of Human Mantle Cell Lymphoma Cells by Activating the Akt Signaling Pathway

STAT5B Suppresses Ferroptosis by Promoting DCAF13 Transcription to Regulate p53/xCT Pathway to Promote Mantle Cell Lymphoma Progression

Objective

The purpose of this study was to analyze the mechanism by which STAT5B inhibits ferroptosis in mantle cell lymphoma (MCL) by promoting DCAF13 transcriptional regulation of p53/xCT pathway.

Methods

The correlations between STAT5B, DCAF13 and ferroptosis in MCL were analyzed using Gene Expression Profiling Interactive Analysis (GEPIA, http://gepia.cancer-pku.cn/index.html). The expression levels and pairwise correlations of STAT5B, DCAF13, p53 and xCT in MCL patients were detected, respectively. STAT5B was silenced to confirm their criticality in MCL ferroptosis. the effects of blocking necrosis, apoptosis and ferroptosis on the anti-MCL effects of STAT5B were examined. Cells with STAT5B overexpression and/or DCAF13 silencing were constructed to confirm the involvement of DCAF13 in the STAT5B-regulated p53/xCT pathway. The regulation of p53 ubiquitination was confirmed by DCAF13 overexpression and MG132. The effects of silencing DCAF13 and MG132 on STAT5B overexpression on MCL was clarified by a tumor-bearing nude mouse model.

Results

DCAF13 was overexpressed in MCL and positively correlated with STAT5B, negatively correlated with p53, and positively correlated with xCT. Inhibition of ferroptosis alleviated the inhibitory effects of siSTAT5B on MCL, while inhibition of necrosis and apoptosis had few effects. Silencing of DCAF13 led to the blocking of STAT5B regulation of p53/xCT and ferroptosis. The changes in DCAF13 and the addition of MG132 did not have statistically significant effects on p53 mRNA. Elevation of DCAF13 resulted in downregulation of p53 protein levels, and this inhibition was reversed by MG132. In animal models, the promotion of MCL and the inhibition of ferroptosis by STAT5B. Silencing of DCAF13 blocked STAT5B inhibition of p53 and induction of xCT, GPX4, and GSH.

Conclusion

STAT5B suppresses ferroptosis by promoting DCAF13 transcription to regulate p53/xCT pathway to promote MCL progression.

Identification of STAT5B as a biomarker associated with prognosis and immune infiltration in breast cancer

BACKGROUND

Breast invasive cancer (BRCA) is the most common malignancy and the second leading cause of malignancy death among women. Signal transducers and activators of transcription (STAT) family played a vital role in regulating certain biological processes and could serve as biomarkers for many diseases or cancers.

METHODS

The expression, prognostic value, and clinical functions of STAT family in BRCA were evaluated with several bioinformatics web portals.

RESULTS

The expression of STAT5A/5B were downregulated in BRCA in subgroup analyses based on race, age, gender, race, subclasses, tumor histology, menopause status, nodal metastasis status, and TP53 mutation. BRCA patients with high STAT5B expression had a better overall survival, relapse free survival, MDFS and post progression survival. STAT5B expression level can impact the prognosis in BRCA patients with positive PR status, negative Her2 status and wild type TP53. Moreover, STAT5B was positively correlated with immune cell infiltration and the level of immune biomarkers. Drug sensitivity revealed that low STAT5B expression was resistant to the many small molecules or drugs. Functional enrichment analysis revealed that STAT5B was involved in adaptive immune response, translational initiation, JAK-STAT signaling pathway, Ribosome, NF-kappa B signaling pathway and Cell adhesion molecules.

CONCLUSIONS

STAT5B was a biomarker associated with prognosis and immune infiltration in breast cancer.

ARID1A knockdown enhances carcinogenesis features and aggressiveness of Caco-2 colon cancer cells: An in vitro cellular mechanism study

Loss of ARID1A, a tumor suppressor gene, is associated with the higher grade of colorectal cancer (CRC). However, molecular and cellular mechanisms underlying the progression and aggressiveness of CRC induced by the loss of ARID1A remain poorly understood. Herein, we evaluated cellular mechanisms underlying the effects of ARID1A knockdown on the carcinogenesis features and aggressiveness of CRC cells. A human CRC cell line (Caco-2) was transfected with small interfering RNA (siRNA) specific to ARID1A (siARID1A) or scrambled (non-specific) siRNA (siControl). Cell death, proliferation, senescence, chemoresistance and invasion were then evaluated. In addition, formation of polyploid giant cancer cells (PGCCs), self-aggregation (multicellular spheroid) and secretion of an angiogenic factor, vascular endothelial growth factor (VEGF), were examined. The results showed that ARID1A knockdown led to significant decreases in cell death and senescence. On the other hand, ARID1A knockdown enhanced cell proliferation, chemoresistance and invasion. The siARID1A-transfected cells also had greater number of PGCCs and larger spheroid size and secreted greater level of VEGF compared with the siControl-transfected cells. These data, at least in part, explain the cellular mechanisms of ARID1A deficiency in carcinogenesis and aggressiveness features of CRC.

Integrative genomic analysis of pediatric T-cell lymphoblastic lymphoma reveals candidates of clinical significance

T-cell lymphoblastic lymphoma (T-LBL) is a heterogeneous malignancy of lymphoblasts committed to T-cell lineage. The dismal outcomes (15%-30%) after T-LBL relapse warrant establishing risk-based treatment. To our knowledge, this study presents the first comprehensive, systematic, integrated, genome-wide analysis including relapsed cases that identifies molecular markers of prognostic relevance for T-LBL. NOTCH1 was identified as the putative driver for T-LBL. An activated NOTCH/PI3K-AKT signaling axis and alterations in cell cycle regulators constitute the core oncogenic program for T-LBL. Mutated KMT2D was identified as a prognostic marker. The cumulative incidence of relapse was 47% ± 17% in patients with KMT2D mutations, compared with 14% ± 3% in wild-type KMT2D. Structural analysis of the mutated domains of KMT2D revealed a plausible impact on structure and functional consequences. These findings provide new insights into the pathogenesis of T-LBL, including high translational potential. The ongoing LBL 2018 trial (www.clinicaltrials.gov #NCT04043494) allows for prospective validation and subsequent fine tuning of the stratification criteria for T-LBL risk groups to improve survival of pediatric patients.

Genotypic and Phenotypic Characteristics of Acute Promyelocytic Leukemia Translocation Variants

Acute promyelocytic leukemia (APL) is a special disease entity of acute myeloid leukemia (AML). The clinical use of all-trans retinoic acid (ATRA) has transformed APL into the most curable form of AML. The majority of APL cases are characterized by the fusion gene PML-RARA. Although the PML-RARA fusion gene can be detected in almost all APL cases, translocation variants of APL have been reported. To date, this is the most comprehensive review of these translocations, discussing 15 different variants. Reviewed genes involved in APL variants include: ZBTB16, NPM, NuMA, STAT5b, PRKAR1A, FIP1L1, BCOR, NABP1, TBLR1, GTF2I, IRF2BP2, FNDC3B, ADAMDTS17, STAT3, and TFG. The genotypic and phenotypic features of APL translocations are summarized. All reported studies were either case reports or case series indicating the rarity of these entities and limiting the ability to drive conclusions regarding their characteristics. However, reported variants have shown variable clinical and morphological features, with diverse responsiveness to ATRA.

Knockdown of SLCO4C1 inhibits cell proliferation and metastasis in endometrial cancer through inactivating the PI3K/Akt signaling pathway

Endometrial cancer (EC) is the second leading type of cancer among women, and its progression is dependent on several factors. The aim of the present study was to examine the effect of solute carrier organic anion transporter family member 4C1 (SLCO4C1) on human EC and determine the underlying molecular mechanism. A total of 57 differentially expressed genes associated with advanced stage and survival were identified in The Cancer Genome Atlas database. In addition, gene ontology analysis indicated that SLCO4C1 was highly expressed in cell differentiation and integral component of plasma membrane. High SLCO4C1 expression in EC tissues was verified by immunohistochemistry. The results demonstrated that the downregulation of SLCO4C1 could significantly suppress the viability, sphere formation, migration and invasion abilities of cells, but enhance apoptosis in EC cell lines. Furthermore, the present results demonstrated that SLCO4C1 had effects on the epithelial-mesenchymal transition (EMT) phenotype in EC cells and regulated the expression of EMT-related proteins. Mechanistically, the present study revealed that SLCO4C1 regulated the biological functions of EC cells by inactivating the PI3K/Akt signaling pathway. Collectively, it was demonstrated that the SLCO4C1/PI3K/Akt pathway may play an important role in EC progression and metastasis and serve as a potential biomarker and target for EC diagnosis and treatment.