Project description:A transient mesenchymal cell in the lung called alveolar myofibroblast (AMF) plays a key role in alveolar formation during postnatal development. However, AMFs are cleared from the alveoli upon lung maturation. We induce exogenous BCL2 expression in these cells using three lineage-specific drivers (Myh11-CreER, PdgfraCreER, and PdgfrbCreER) to prevent AMF clearance. We use scRNA seq to analyze the transcriptomic changes of AMFs upon BCL2 expression and subsequent persistence in the lung. Additionally, we evaluated the consequences driven by persistent AMFs in other cell lineages at a transcriptional level.
Project description:SOX9 was identified as a prognostic biomarker particularly in IGH-BCL2 translocated germinal center B cell (GCB) subtypes of the diffuse large B cell lymphoma (DLBCL) and plays a vital role in lymphomagenesis. However, the molecular mechanism that modulating the aberrant expression of SOX9 in this DLBCL subset remains unknown. We have demonstrated that SOX9 enhanced IGH-BCL2 positive DLBCL subset resistance to either chemotherapy or BCL2 inhibitor. Moreover, we found that inhibition of BCL2 downregulates SOX9 in IGH-BCL2 positive DLBCL subset. We further identified that IRF4 is a key regulator to mediate BCL2 induced SOX9 expression, alongside with the chip-seq confirmed that IRF4 is a key transcription factor for SOX9 in DLBCL. In addition, BCL2 promote IRF4 entry into the nucleus by enhancing its protein stability, via downregulating of proteosome ubiquitination process, and, therefore, enforce SOX9-mediated phenotypes. Finally, we showed in DLBCL cell lines and xenografted mice model that in vivo inhibition of IRF4 with hIRF4 antisense oligonucleotide (ASO) repressed lymphomagenesis and DLBCL chemoresistance. Altogether, our data support the conclusion that IRF4 plays an essential role in BCL2 induced upregulation of SOX9 expression, and targeting IRF4 may represent a promising therapeutic strategy to cure relapse and refractory DLBCL in the future.
Project description:In analyzing transcriptomic data from a clinical trial of neoadjuvant-intensive Androgen Deprivation Therapy, we observed increased mRNA expression of the hallmark antiapoptotic gene BCL2 in the prostate tumors of treated patients versus those of untreated patients. We showed that BCL2 overexpressed LNCaP cells exhibited resistance to enzalutamide, indicating that BCL2-overexpression leads to castration resistance and cellular plasticity.We performed RNA sequencing on BCL2 overexpressed LNCaP cells tretaed with R1881 to determine BCL2 regulated AR signaling and overed that BCL2 overexpression may alter AR-pathway.
Project description:Activation of the MYC oncogene is common in B-cell lymphomas, and frequently associated with compensatory events that dampen Myc-induced apoptosis, such as over-expression of anti-apoptotic Bcl2-family proteins. For example, concurrent translocations of MYC and BCL2 in a subset of Diffuse large B-cell lymphoma (DLBCL) lead to the high-grade “double-hit” lymphoma subtype (DHL), characterized by dismal prognosis in the face of current front-line regimens, thus calling for the pursuit of tailored therapeutic strategies. Here, we show that Myc and Bcl2 modulate the sensitivity of B-cells to IACS-010759, a selective inhibitor of mitochondrial respiratory complex I. Myc activation in non-transformed lymphoid precursors suppressed endogenous Bcl2 and sensitized the cells to IACS-010759-induced apoptosis. Treatment with the Bcl2 inhibitor venetoclax also sensitized to IACS-010759, while overexpression of Bcl-2 was protective. IACS-010759 engaged an ATF4-driven Integrated Stress Response (ISR) with dual anti- and pro-apoptotic effects, the latter mediated by the CHOP transcription factor, which contributed to selective killing of Myc-overexpressing cells. In line with the above data, IACS-010759 and venetoclax synergized in killing human DHL cells, and showed strong combinatorial effects in a pre-clinical setting. In a Bcl2-negative Burkitt’s lymphoma cell line, instead, IACS-010759 synergized with the Mcl-1 inhibitor S63845. Altogether, our data point to the combination of IACS-010759 with distinct Bcl2-family inhibitors for therapeutic reactivation of the intrinsic apoptotic pathway in Myc-associated B-cell lymphomas
Project description:In analyzing transcriptomic data from a clinical trial of neoadjuvant-intensive Androgen Deprivation Therapy, we observed increased mRNA expression of the hallmark antiapoptotic gene BCL2 in the prostate tumors of treated patients versus those of untreated patients. We showed that BCL2 overexpressed LNCaP cells exhibited resistance to enzalutamide, indicating that BCL2-overexpression leads to castration resistance and cellular plasticity.We treted the LNCaP cells with Bcl2 inhibitor Venetoclax in under castration of in presence of Androgen for 24 hr and observed that androgen supressed Venetoclax function
Project description:S49 (Neo) cells die by apoptosis following dexamethasone (dex) treatment whereas S49 cells expressing Bcl2 are resistant to glucocorticoid-induced cell death. Provocatively, mimicking the loss of intracellular potassium using a low dose of a microbial toxin that acts as a potassium ionophore in combination with dex overcame the resistance afforded by Bcl2 and killed the cells. The ability of the microbial toxin to trigger apoptosis of S49 (Bcl2) cells depends critically on the duration of dex treatment, as a 48-hour dex treatment sensitized the cells to die whereas a 24-hour exposure did not. To determine how the glucocorticoid signaling profile differs at these two time points, we performed RNAseq on RNA isolated from S49 (Neo) cells and S49 (Bcl2) cells treated with and without dex for 24 and 48 hours.
Project description:A subset of FL in adults are negative for t(14;18) translocation and BCL2 expression The tumor shows low grade cytology and lack both BCL2 expression and t(14;18) translocation. The genetic alterations involved in the pathogenesis of FL without t(14;18)-negative translocation and BCL2 expression are not well known.