Targeting BCL6 in Gastrointestinal Stromal Tumor Promotes p53-Mediated Apoptosis to Enhance the Antitumor Activity of Imatinib

B Cell Lymphoma 6 (BCL6): A Conserved Regulator of Immunity and Beyond

B cell lymphoma 6 (BCL6) is a conserved multi-domain protein that functions principally as a transcriptional repressor. This protein regulates many pivotal aspects of immune cell development and function. BCL6 is critical for germinal center (GC) formation and the development of high-affinity antibodies, with key roles in the generation and function of GC B cells, follicular helper T (Tfh) cells, follicular regulatory T (Tfr) cells, and various immune memory cells. BCL6 also controls macrophage production and function as well as performing a myriad of additional roles outside of the immune system. Many of these regulatory functions are conserved throughout evolution. The BCL6 gene is also important in human oncology, particularly in diffuse large B cell lymphoma (DLBCL) and follicular lymphoma (FL), but also extending to many in other cancers, including a unique role in resistance to a variety of therapies, which collectively make BCL6 inhibitors highly sought-after.

Intratumoral microbiome promotes liver metastasis and dampens adjuvant imatinib treatment in gastrointestinal stromal tumor

Understanding the determinants of long-term liver metastasis (LM) outcomes in gastrointestinal stromal tumor (GIST) patients is crucial. We established the feature selection model of intratumoral microbiome at the surgery, achieving robust predictive accuracies of 0.953 and 0.897 AUCs in discovery (n = 74) and validation (n = 34) cohorts, respectively. Notably, despite the significant reduction in LM occurrence with adjuvant imatinib (AI) treatment, intratumoral microbiome exerted independently stronger effects on post-operative LM. Employing both 16S and full-length rRNA sequencing, we pinpoint intracellular Shewanella algae as a foremost LM risk factor in both AI- and non-AI-treated patients. Experimental validation confirmed S. algae's intratumoral presence in GIST, along with migration/invasion-promoting effects on GIST cells. Furthermore, S. algae promoted LM and impeded AI treatment in metastatic mouse models. Our findings advocate for incorporating intratumoral microbiome evaluation at surgery, and propose S. algae as a therapeutic target for LM suppression in GIST.

Enhanced understanding of cinnamaldehyde's therapeutic potential in osteoarthritis through bioinformatics and mechanistic validation of its anti-apoptotic effect

Introduction

Osteoarthritis (OA) is a globally prevalent joint disorder affecting approximately 240 million individuals worldwide. Cinnamaldehyde, known for its broad anti-inflammatory and anti-aging effects across various cell types, has not been investigated for its potential impact on apoptosis in OA chondrocytes.

Methods

To explore the effectiveness of cinnamaldehyde in mitigating knee osteoarthritis by reducing chondrocyte apoptosis, bioinformatics analysis was first conducted to identify apoptosis-associated differentially expressed genes (APDEGs). Gene expression datasets GSE55235 and GSE114007 were analyzed using weighted gene co-expression network analysis (WGCNA). Gene modules of interest were cross-referenced with APDEGs to identify those specific to OA. LASSO regression analysis was employed to build a risk model, and this model, along with datasets GSE114007, GSE55457, and GSE12021, was validated using ROC analysis. Cellular experiments and blood analyses from OA patients were performed to evaluate the effects of cinnamaldehyde on apoptosis-related gene expression.

Results

Cinnamaldehyde administration was found to rectify the abnormal expression of key apoptosis-related genes in OA patients. Specifically, cinnamaldehyde may affect knee osteoarthritis by regulating apoptosis-related genes such as ZFAND5, BCL6, ELL2, FOSL2, MARCKS, and SGCD. Additionally, three novel apoptotic targets in OA chondrocytes-ZFAND5, ELL2, and SGCD-were identified.

Discussion

These findings provide significant theoretical support for the clinical use of cinnamaldehyde in OA treatment. The discovery of novel apoptotic targets presents new therapeutic possibilities for future OA interventions.

Genome-wide CRISPR screen identifies ESPL1 limits the response of gastric cancer cells to apatinib

Apatinib was the first anti-angiogenic agent approved for treatment of metastatic gastric cancer (GC). However, the emergence of resistance was inevitable. Thus investigating new and valuable off-target effect of apatinib directly against cancer cells is of great significance. Here, we identified extra spindle pole bodies-like 1 (ESPL1) was responsible for apatinib resistance in GC cells through CRISPR genome-wide gain-of-function screening. Loss of function studies further showed that ESPL1 inhibition suppressed cell proliferation, migration and promoted apoptosis in vitro, and accordingly ESPL1 knockdown sensitized GC cells to apatinib. In addition, we found ESPL1 interacted with mouse double minute 2 (MDM2), a E3 ubiquitin protein ligase, and the combination of MDM2 siRNA with apatinib synergistically ameliorated the resistance induced by ESPL1 overexpression. In summary, our study indicated that ESPL1 played a critical role in apatinib resistance in GC cells. Inhibition of MDM2 could rescue the sensitivity of GC cells to apatinib and reverse ESPL1-mediated resistance.