Sanjay Kumar

An altered proteome in ovarian cancer stem-like cells: profiling of the mDivi-1 induced proteome and its clinical significance

Abstract A three-dimensional (3D) spheroid culture mimics in vivo conditions and reproduces the tumor microenvironment, thus providing more physiological relevance to disease conditions. Mapping the proteome profile in 3D-cultured ovarian cancer (OC) spheroids helps identify novel and potential therapeutic targets in ovarian cancer stem cells. We used mass-spectrometry-based comparative proteome profiling for two-dimensional (2D)-cultured adherent and 3D-cultured OC spheroids and identified 94 upregulated and 54 downregulated proteins in 3D-cultured A2780 spheroids compared to 2D-cultured adherent A2780 cells. In SKOV-3 cells, we identified 127 upregulated proteins and 192 downregulated proteins in 3D-cultured spheroids compared to 2D-cultured adherent cells. The differentially expressed proteins were enriched in proteins regulating oxidative phosphorylation, the acetyl-CoA metabolic process, RNA polymerase core enzyme binding, and growth factor binding. In addition, we also mapped the proteome profile after the treatment with a mitochondrial fission inhibitor, mDivi-1, of 3D-cultured cells and defined the correlation between significantly upregulated and downregulated genes and their association with the progression-free survival of OC patients.

Patient-derived organoids in ovarian cancer: Current research and its clinical relevance

Regardless of recent advances in cancer treatment, ovarian cancer (OC) patients have had a five-year survival rate of 48% in the last few decades. Diagnosis at the advanced stage, disease recurrence, and lack of early biomarkers are the severe clinical challenges associated with disease survival rate. Identifying tumor origin and developing precision drugs will effectively advance OC patient's treatment. The lack of a proper platform to identify and develop new therapeutic strategies in OC treatment necessitates searching for a suitable model to address tumor recurrence and therapeutic resistance. The development of the OC patient-derived organoid model provided a unique platform to identify the exact origin of high-grade serous OC, drug screening, and the development of precision medicine. This review provides an overview of recent progress in developing patient-derived organoids and their clinical relevance. Here, we outline their uses for transcriptomics and genomics profiling, drug screening, translational study, and their future perspective and clinical outlook as a model to advance OC research that could offer a promising approach for developing precision medicine.

Mfn2-mediated mitochondrial fusion promotes autophagy and suppresses ovarian cancer progression by reducing ROS through AMPK/mTOR/ERK signaling

Mitochondrial dynamics are balanced fission and fusion events that regulate mitochondrial morphology, and alteration in these events results in mitochondrial dysfunction and contributes to many diseases, including tumorigenesis. Ovarian cancer (OC) cells exhibit fragmented mitochondria, but the mechanism by which mitochondrial dynamics regulators contribute to OC is considerably less clear. Here, we elucidated the potential role of Mfn2-mediated mitochondrial fusion in OC and present evidence that genetic or pharmacological activation of Mfn2 leads to mitochondrial fusion and reduces ROS generation, which correlates with reduced cell proliferation, invasion, migration, and EMT in OC cells. Also, increased mitochondrial fusion promotes the F-actin remodeling, reduces lamellipodia formation, and thus reduces EMT. Increased expression of Mfn2 triggers AMPK, promotes autophagy, reduces ROS, and suppresses OC progression by downregulating  the p-mTOR (2481 and 2448) and p-ERK axis. OC patients with higher Mfn2 expression have better survival than those with lower Mfn2 levels. Our findings demonstrate that restoration of Mfn2-mediated mitochondrial fusion suppressed OC progression and suggest that this process could be a potential strategy in OC treatment.

KLF8 is activated by TGF‐β1 via Smad2 and contributes to ovarian cancer progression

AbstractKrüppel‐like factor 8 (KLF8) is a transcription factor expressed abnormally in various cancer types and promotes oncogenic transformation. However, the role of KLF8 in ovarian cancer (OC) progression remains unclear. This study reports that transforming growth factor‐β1 (TGF‐β1)/Smad2/KLF8 axis regulates epithelial–mesenchymal transition (EMT) and contributes to OC progression. We analyzed the KLF8 expression in OC cells and tissues, wherein a significant overexpression of KLF8 was observed. Increased KLF8 expressions were correlated with higher cell proliferation, EMT, migration, and invasion and conferred poor clinical outcomes in OC patients. Overexpressed KLF8 increases F‐actin polymerization and induces cytoskeleton remodeling of OC cells. Furthermore, a dissection of the molecular mechanism defined that TGF‐β1 triggers KLF8 through the Smad2 pathway and regulates EMT. Pharmacological and genetic inhibition of Smad2 followed by TGF‐β1 treatment failed to activate KLF8 expression and induction of EMT. Using promoter‐luciferase reporter assays, we defined that upon TGF‐β1 activation, phosphorylated Smad2 binds and promotes the KLF8 promoter activity, and knockdown of Smad2 inhibits KLF8 promoter activation. Together, these results demonstrate that TGF‐β1 activates KLF8 expression by the Smad2 pathway, and KLF8 contributes to OC progression and may serve as a potential therapeutic strategy for treating OC patients.