Project description:Monomethyl auristatin E (MMAE) is used as the cytotoxic payload for enfortumab vedotin (EV) in the treatment of locally advanced and metastatic bladder cancer (BC). However, the development of resistance to MMAE in BC is a therapeutic problem. To explore the mechanism of resistance to MMAE in BC, we established MMAE-resistant BC cells (MR-BCs). RNA sequencing analysis showed that the expression of dipeptidyl peptidase 4 (DPP4, also called CD26) increased significantly in MR-BCs compared with parental BC cells. Knock down of DPP4 expression using small interfering RNA inhibited the viability of MR-BCs. In addition, the DPP4 inhibitor sitagliptin suppressed the proliferation, migration, and invasion of BC cells, and cotreatment with MMAE effectively induced cell apoptosis, arrested cells in the G2M phase of the cell cycle, increased reactive oxygen species production by inhibiting the AKT pathway, and significantly inhibited the in vivo growth of MMAE-resistant cells. This study provides insights into the use of DPP4 inhibitors as a treatment strategy for MMAE-resistant BC.
Project description:Bladder cancer characterized by RNA methylation abnormalities and NOTCH pathway dysregulation exhibits high recurrence that remains the major obstacle for bladder cancer treatment. Targeting methyltransferase-like 3 (METTL3) and NOTCH signal is a potential strategy to block bladder cancer progression. However, the underlying mechanisms by which METTL3-manipulated NOTCH signal and its effect on bladder cancer tumorigenesis remain to be clarified. Here we showed that METTL3-guided m6A modification methylated pri-miR-146 at the flaking sequence, which was responsible for the pri-miR-146 maturation. Furthermore, NUMB/NOTCH2 axis was identified as the functional downstream target signal that mediated the pro-survival role of miR-146a-5p in bladder cancer cells. Therapeutically, the polypeptide melittin was demonstrated to induce apoptosis of bladder cancer cells in a METTL3-dependent manner. Importantly, METTL3 and miR-146a-5p were positively correlated with recurrence and poor prognosis of bladder cancer patient. Our studies indicate that METTL3/miR-146a-5p/NUMB/NOTCH2 axis could be a potential therapeutic target for recurrent bladder cancer treatment and METTL3 acts as a fate determinant that controls sensitivity of bladder cancer cells to melittin treatment.
Project description:Skin-injury and several diseases elicit fibrosis and induce hair follicle (HF)-growth arrest and loss. Resulting alopecia and disfiguration represent a severe burden for patients both physically and psychologically. Reduction of pro-fibrotic factors such as DPP4 might be a strategy to tackle this issue. We demonstrate DPP4-overrepresentation in settings with HF-growth arrest (telogen), HF-loss and non-regenerative wound areas in mice skin and human scalp. Topical DPP4-inhibition (DPP4i) with FDA/EMA-approved Sitagliptin (Sit) on preclinical models of murine HF-activation/regeneration results in accelerated anagen-progress, while treatment of wounds with Sit results in reduced expression of fibrosis markers, increased induction of anagen around wounds, and HF-regeneration in the wound center. These effects are associated with higher expression of Wnt-target Lef1, known to be required for HF-anagen (HF-activation)/regeneration. Sit-treatment decreases pro-fibrotic signaling in the skin, induce a differentiation trajectory of HF-cells, and activate Wnt-targets related to HF-activation/growth but not those supporting fibrosis. Taken together, our study demonstrates a role for DPP4 in HF biology and shows how DPP4i, currently used as oral medication to treat diabetes, could be repurposed into a topical treatment agent to potentially reverse HF-loss in alopecia and after injury.
Project description:Transcriptional profiling of primary human white preadipocytes after infection with lentiviral vector either containing shRNA directed against dipeptidypeptidase 4 (DPP4) or unspecific shRNA as negative control Treatment of cells with DPP4 shRNA or control shRNA was done in 4 biological replicates, the first sample of DPP4 KD was hybridized against the first sh-control sample, the second DPP4 smple against the second control sample and so on
Project description:ARID1A, a subunit of SWI/SNF chromatin remodeling complex. SWI/SNF complex can regulate expression of genes involved in vital biological processes such as cell cycle, DNA damage repair and development. ARID1A is known to have high mutation rate in human cancers including bladder cancer, leading to its loss of function. Publicly available whole exome sequencing data for muscle invasive and non-muscle invasive bladder cancers, show fraction of tumors with truncated ARID1A. Thus identifying therapeutic strategies for ARID1A mutant cancers is of high importance. EZH2, a histone methyltransferase is known to over-express and play pivotal role in aggressive bladder cancer. Our preliminary studies show that treatment of EZH2 inhibitor (GSK126) on ARID1A mutant bladder cancer cells significantly reduced cancer cell viability, invasion and colony formation relative to wild type ARID1A containing cells. Here, we performed microarray experiments to assess the effect of EZH2 inhibitor on global transcriptome of both ARID1A mutant and wild type bladder cancer cell line.
Project description:We report here the overexpression of DPP4 in C28/I2 chondrocyte cells to investigate the changes induced by elevated levels of this gene. DPP4 is known as a marker of cellular senescence, yet its regulatory mechanisms remain unclear. In this study, we utilized the C28/I2 cell line to overexpress DPP4 and analyzed the resultant effects on gene expression and cellular behavior. Our findings reveal that DPP4 overexpression influences several pathways associated with chondrocyte function and senescence. Specifically, we observed alterations in pathways related to extracellular matrix organization, inflammatory response, and cellular aging. These results suggest that DPP4 plays a significant role in the modulation of chondrocyte senescence and may provide new insights into the mechanisms of cellular aging. Taken together, our data provide a molecular framework for understanding how DPP4 overexpression impacts chondrocyte physiology and offers potential targets for therapeutic intervention in age-related cartilage diseases.
Project description:In hypoxic pulmonary hypertension (PH), pulmonary vascular remodeling is characterized by the emergence of activated adventitial fibroblasts, leading to medial smooth muscle hyperplasia. Previous studies have suggested that CD26/dipeptidyl peptidase-4 (DPP4) plays a crucial role in the pathobiological processes in lung diseases. However, its role in pulmonary fibroblasts in hy-poxic PH remains unknown. Therefore, we aimed to clarify the mechanistic role of CD26/DPP4 in lung fibroblasts in hypoxic PH. Dpp4 knockout (Dpp4 KO) and wild-type (WT) mice were exposed to hypoxia for 4 weeks. The degree of PH severity and medial wall thickness was augmented in Dpp4 KO mice compared with that in WT mice, suggesting that CD26/DPP4 plays a suppressive role in the development of hypoxic PH. Transcriptome analysis of human lung fibroblasts cultured under hypoxic conditions revealed that TGFB2, TGFB3, and TGFA were all upregulated as differentially expressed genes after DPP4 knockdown with small interfering RNA treatment. These results suggest that CD26/DPP4 plays a suppressive role in TGFβ signal-regulated fibroblast ac-tivation under hypoxic conditions. Therefore, CD26/DPP4 may be a potential therapeutic target in patients with PH associated with chronic hypoxia.