RUNX2 prompts triple negative breast cancer drug resistance through TGF-ß pathway regulating breast cancer stem cells.

Triple-negative breast cancer (TNBC) stands out as the most aggressive subtype within the spectrum of breast cancer. The current clinical guidelines propose treatment strategies involving cytotoxic agents like epirubicin or paclitaxel. However, the emergence of acquired resistance frequently precipitates secondary tumor recurrence or the spread of metastasis. In recent times, significant attention has been directed toward the transcription factor RUNX2, due to its pivotal role in both tumorigenesis and the progression of cancer. Previous researches suggest that RUNX2 might be intricately linked to the development of resistance against chemotherapy, with its mechanism of action possibly intertwined with the signaling of TGF-ß. Nevertheless, the precise interplay between their effects and the exact molecular mechanisms underpinning chemoresistance in TNBC remain elusive. Therefore, we have taken a multifaceted approach from in vitro and in vivo experiments to validate the relationship between RUNX2 and TGF-ß and to search for their pathogenic mechanisms in chemoresistance. In conclusion, we found that RUNX2 affects chemoresistance by regulating cancer cell stemness through direct binding to TGF-ß, and that TGF-ß dually regulates RUNX2 expression. The important finding will provide a new reference for clinical reversal of the development of chemoresistance in breast cancer.

Identification of stromal cell proportion-related genes in the breast cancer tumor microenvironment using CorDelSFS feature selection: implications for tumor progression and prognosis.

Background: The tumor microenvironment (TME) of breast cancer (BRCA) is a complex and dynamic micro-ecosystem that influences BRCA occurrence, progression, and prognosis through its cellular and molecular components. However, as the tumor progresses, the dynamic changes of stromal and immune cells in TME become unclear. Objective: The aim of this study was to identify differentially co-expressed genes (DCGs) associated with the proportion of stromal cells in TME of BRCA, to explore the patterns of cell proportion changes, and ultimately, their impact on prognosis. Methods: A new heuristic feature selection strategy (CorDelSFS) was combined with differential co-expression analysis to identify TME-key DCGs. The expression pattern and co-expression network of TME-key DCGs were analyzed across different TMEs. A prognostic model was constructed using six TME-key DCGs, and the correlation between the risk score and the proportion of stromal cells and immune cells in TME was evaluated. Results: TME-key DCGs mimicked the dynamic trend of BRCA TME and formed cell type-specific subnetworks. The IG gene-related subnetwork, plasmablast-specific expression, played a vital role in the BRCA TME through its adaptive immune function and tumor progression inhibition. The prognostic model showed that the risk score was significantly correlated with the proportion of stromal cells and immune cells in TME, and low-risk patients had stronger adaptive immune function. IGKV1D-39 was identified as a novel BRCA prognostic marker specifically expressed in plasmablasts and involved in adaptive immune responses. Conclusions: This study explores the role of proportionate-related genes in the tumor microenvironment using a machine learning approach and provides new insights for discovering the key biological processes in tumor progression and clinical prognosis.

The effect of Banxia-houpo decoction on CUMS-induced depression by promoting M2 microglia polarization via TrkA/Akt signalling.

It has been reported that Banxia-houpo decoction (BXHPD) serves as the anti-depressant treatment for a mild and severe depressive disease with limited side effects. The present study was performed to evaluate the protective effect of BXHPD on chronic unpredicted mild stress (CUMS)-induced depression and explore its effect on TrkA/Akt-mediated microglia polarization. The CUMS procedure was carried out, and the mice were intragastrically treated with BXHPD once daily. The selective TrkA inhibitor GW441756 was applied to further investigate the role of TrkA in BXHPD-mediated microglia polarization. The behaviour test including open field test (OFT), sucrose preference test (SPT), novelty-suppressed feeding test (NSFT), tail suspension test (TST) and forced swim test (FST) was performed. The concentrations of pro-inflammatory cytokines IL-6, TNF-α, IL-1ß, IL-12 and anti-inflammatory cytokines IL-4, IL-10 were determined using Enzyme-linked immunosorbent assay. The population of Iba1+ cells and the length of microglia processes were observed under the fluorescence microscope. The mRNA expressions of Arg1, Ym1 and Fizzl1 were measured by PCR. The protein expressions of TrkA, p-Tyr490-TrkA, p-Ser473-Akt, p-Ser473-Akt1, p-Ser474-Akt2, p-CREB and Jmjd3 were detected by western blot. Our results showed that BXHPD attenuated CUMS-induced depressive-like behaviour, promoted anti-inflammatory cytokines, inhibited pro-inflammatory cytokines, suppressed microglia activation, promoted M2 phenotype-specific indices and upregulated the expressions of TrkA, p-Tyr490-TrkA, p-Ser473-Akt, p-Ser473-Akt1, p-Ser474-Akt2, p-CREB and Jmjd3. The above beneficial effect of BXHPD can be blocked by TrkA inhibitor GW441756. This work demonstrated that BXHPD exerted an anti-depressant effect by promoting M2 phenotype microglia polarization via TrkA/Akt pathway.

miR-205/RunX2 axis negatively regulates CD44+/CD24- breast cancer stem cell activity.

Breast Cancer stem cells (BCSCs) have been extensively studied and have been used directly as a therapeutic target, but how the BCSCs themselves are regulated remain unclear. Here we reported identification of miR-205 that may act as a tumor suppressor and negatively-regulate BCSCs stemness and tumor malignance. By qRT-PCR analysis, we have shown that miR-205 was decreased in CD44+/CD24-/low BCSCs compared with non-BCSCs. We have also shown that miR-205 expression level was very low in MB-231 cells with high BCSC percentage, while relatively high in MCF-7 cells with low BCSC percentage. We then overexpressed miR-205 in MB-231 and SUM-149 cells and knocked it down in MCF-7 and BT-474 cells respectively. Our results showed that overexpression of miR-205 could reduce CD44+/CD24-/low population percentage in MB-231 cells. The mechanism might associate with mesenchymal-epithelial transition (MET). Finally, we found an important transcriptional factor and oncogene, RunX2, was a target gene of miR-205. miR-205 overexpression could inhibit breast cancer malignancy by regulating RunX2 both in vitro and in vivo. A rescue experiment by cotransfection of RunX2 and miR-205 into the MCF-7 cell line attenuate cell proliferation, invasion, migration, CD44+/CD24-/low population, mammosphere formation abilities and xengraft tumor formation. Together, our results support that miR-205 is a tumor suppressor during breast cancer development.

TGF-ß plays a vital role in triple-negative breast cancer (TNBC) drug-resistance through regulating stemness, EMT and apoptosis.

Triple negative breast cancer (TNBC) is the most malignant subtype of breast cancer in which the cell surface lacks usual targets for drug to exhibit its effects. Epirubicin (Epi) is widely used for TNBC, but a substantial number of patients develop Epi resistance that is usually associated with poor prognosis. Transforming growth factor (TGF-ß) is a multifunctional cytokine. In recent study, it appears that TGF-ß influences the cancer stem cell population, thus, the drug resistance of cancer may also be affected. We used epirubicin to treat MDA-MB-231 (MB-231) cells and found that TGF-ß and breast cancer stem cell markers CD44+CD24- were increased and were dose-dependent of epirubicin. We established drug-resistant cell line from parental MB-231 cells by chronic treatment with low-concentration epirubicin. The MB-231/Epi cell line showed relatively slow growth rate with varied morphology. Transwell assay and drug sensitivity assay revealed that the malignant cell behaviors in terms of migration, invasion and epirubicin-resistant properties were markedly increased in the MB-231/Epi cells. Western blot, immunofluorescence assay, and flow cytometry were used to analyze the expression levels of the breast cancer stem cell markers, CD44 and CD24. Mammospheres assay showed that the stemness of MB-231/Epi was increased compared to their parental cells. Interestingly, MB-231/Epi cells showed different expression levels of apoptosis-related markers: Bcl2, Bax; EMT-related markers E-cadherin, N-cadherin and cell cycle-related marker cyclinD1. These genes have all been shown to be regulated by the TGF-ß pathway. Taken together, our findings suggest that TGF-ß plays a vital role in TNBC epirubicin-resistance through regulating stemness, EMT and apoptosis.

Involvement of brain-gut axis in treatment of cerebral infarction by ß-asaron and paeonol.

Cerebral infarction (CI) causes severe brain damage with high incidence. This study aimed to investigate the involvement of brain-gut axis in the treatment of CI by combined administration of ß-asaron and paeonol. Rat middle cerebral artery occlusion (MCAO) model was established, the interleukin-1beta (IL-1ß) and tumor necrosis factor α (TNF-α) in the rat peripheral blood were determined by ELISA assay, and brain tissue damage was evaluated by TUNNEL assay. The correlation of cholecystokinin (CCK) and nuclear factor-kappaB (NF-κB) signaling components between intestinal mucosa and prefrontal cortex of MCAO rats treated with ß-asaron and paeonol were analyzed by quantitative RT-PCR and western blotting. In vitro transwell co-culture was performed to confirm the correlated expression. The expression of CCK and NF-κB signaling components were closely correlated between the intestinal mucosa and prefrontal cortex of MCAO rats treated with ß-asaron and paeonol. The combined administration also regulates the IL-1ß and TNF-α in the MCAO rat peripheral blood and ameliorate the brain damage in MCAO rats. Elevated expression of related genes was observed in the cortical neurons co-cultured with intestinal mucosal epithelial cells treated by ß-asaron and paeonol. The brain-gut axis mediates the therapeutic effect of ß-asaron and paeonol for cerebral infarction through CCK and NF-κB signaling.