Biology subjects

Edatt, L.

Publications and source records attributed to Edatt, L..

4 recordsLinked to original sources

bioRxiv2025

Isolation Methods of Tumor Endothelial Cells Impact AngiomiR Profiles

MicroRNAs (miRNAs) play an important role in endothelial cell growth and differentiation. Tumor angiogenesis-specific miRNAs (angiomiRs) are a subset of miRNAs that are dyregulated in tumor endothelial cells. Because of the importance of angiogenesis in cancer progression, regulation of angiomiRs may have significant therapeutic implications. However, discovery of angiomiRs has often been limited by biased model systems that may not be valid. Here, we evaluated whether the variable expression levels of angiomiRs in endothelial cells were impacted by the isolation methods used to profile them. Using an autochthonous, genetically engineered mouse model of lung adenocarcinoma, we used Nanostring to profile miRNA expression levels of normal lung endothelial cells (NECs) to tumor endothelial cells (TECs) using two endothelial cell (EC) isolation methods: 1) staining and sorting ECs directly from tumors ("in vivo"), and 2) magnetic bead isolation and sub-cloning ECs ("in vitro"). We then compared candidate angiomiRs with the profiles from two orthotopic, immunocompetent lung cancer models. When TECs were directly enriched from tumors ("in vivo" method), three candidate angiomiRs (miR-30b, miR-1981, and miR-707) were significantly lower in TECs than NECs. In contrast, when ECs were isolated and cultured ("in vitro" method), three different candidate angiomiRs (miR-200a, miR-124 and miR-186) were significantly lower in TECs than NECs. Using two independent model systems for validation, we found miR-30b to be significantly reduced in TECs using freshly sorted ECs. Conversely, the in vitro discovered angiomiR candidates did not validate in these model systems, suggesting that TECs grown in vitro may not maintain relevant angiomiR profiles or serve as an adequate method for molecular profiling. Our findings demonstrate that angiomiR expression patterns are impacted by isolation methods. Instead of relying on ECs cultured in vitro, we suggest careful validation studies of cells freshly collected from tumors before determining whether a miRNA is a bona fide angiomiR.

molecular biology↗

bioRxiv2024

MicroRNA 21 induces carcinogenesis in hepatic cells by modulating mitochondrial metabolism

Mitochondria plays crucial role in cells survivability and normal functioning. But in the case of cancer, the mitochondrial machinery (ETC) is altered and glycolytic pathway is activated as an alternate source of energy. The main reason behind the reprogramming of mitochondrial machinery could be mutations in mitochondrial genes or suppression of genes involved in normal functioning of the mitochondria. MicroRNAs could be a key player in modulating the mitochondrial metabolism, as they have targets on various important mitochondrial genes involved in the Electron Transport Chain of the mitochondria. Any alteration in the expression pattern of the mitochondrial genes would directly contribute to the modulation of normal functioning of the mitochondrial machinery. Micro RNA 21 is an oncomiR, located at q arm of the 17th chromosome. MiR 21 has been reported to be involved in many types of cancer. MiR 21 is reported to have targets on many important genes, crucial for cell survivability and proliferation, most of which falls in the category of tumor suppressor genes. With our bioinformatics analysis, we found that miR 21 has targets on important mitochondrial genes involved in the ETC. So, we tried to elucidate the role of miR 21 in modulation of the mitochondrial machinery and role of this alteration in the mitochondrial mechanism in carcinogenesis. Our results revealed that miR 21 have targets on the Cytochrome C Oxidase 1 (Cox1), which is directly involved in the Complex 4 of the electron transport chain. Next we checked the phenotypic effects of this down regulation of Cox1 by measuring the oxygen consumption by the mitochondria and found that O2 consumption goes significantly down in miR 21 over expressing cells. Along with this, we also checked if exosomes from miR 21 overexpressing cancer cells could induce the carcinogenesis in the normal hepatic cells and found that miR 21 accelerates the rate of cellular migration and enhances the colony formation. The results together suggest that miR 21 posses carcinogenic property, possibly by modulating mitochondrial machinery.

cancer biology↗

bioRxiv2024

MicroRNA 106b: Role in the reprograming of mitochondrial machinery and carcinogenesis in hepatic cells

Cancer is a disease of unregulated cell growth. The process of initiation and progression of cancer is called carcinogenesis and the factors possessing ability to induce carcinogenesis are called carcinogens. Along with the coding sequence, the non-coding sequence also play very crucial role in the process of carcinogenesis. MicroRNAs are small non-coding RNAs having targets on both the classes of genes important in cancer i.e., oncogenes and tumour suppressor genes, thus act as key play in carcinogenesis. Dysfunctional mitochondrial metabolism has been widely reported in cancer and this malfunctioning could be brought in by suppression of the expression pattern of important mitochondrial genes by microRNAs. Our in-silico analysis revealed that miR 106b possess targets on several important mitochondrial genes involved in various complexes of electron transport chain. Further, we checked the role of miR 106b in reprogramming of the mitochondrial mechanism and carcinogenesis. The results suggested that miR 106b contributes to carcinogenesis in hepatic cells by modulating the mitochondrial metabolism.

cancer biology↗

bioRxiv2022

Periostin+ stromal cells guide lymphovascular invasion by cancer cells

Cancer cell dissemination to the sentinel lymph node associates with poor patient outcomes, particularly in breast cancers. How cancer cells egress the primary tumor upon interfacing with the lymphatic vasculature is complex and driven by dynamic interactions between cancer cells and stromal cells including cancer associated fibroblasts (CAFs). The matricellular protein periostin can distinguish CAF subtypes in breast cancer and is associated with increased desmoplasia and disease recurrence in patients. However, since periostin is secreted, periostin-expressing CAFs are difficult to characterize in situ, limiting our understanding of their specific contribution to cancer progression. Here, we used in vivo genetic labelling and ablation to lineage trace periostin+ cells and characterize their function(s) during tumor growth and metastasis. We report that periostin-expressing CAFs are spatially found at periductal and perivascular margins, are enriched at lymphatic vessel peripheries, and are differentially activated by highly-metastatic cancer cells versus low-metastatic counterparts. Surprisingly, genetically depleting periostin+ CAFs slightly accelerated primary tumor growth but impaired intratumoral collagen organization and inhibited lymphatic, but not lung, metastases. Periostin ablation in CAFs impaired their ability to deposit aligned collagen matrices and inhibited cancer cell invasion through collagen and across lymphatic endothelial cell monolayers. Thus, highly-metastatic cancer cells mobilize periostin-expressing CAFs in the primary tumor site which promote collagen remodeling and collective cell invasion within lymphatic vessels and ultimately to sentinel lymph nodes. Significance StatementMetastatic disease causes the majority of cancer-related deaths but is challenging to treat as it is a complex multi-step process driven by heterotypic cell interactions. Cancer-associated fibroblasts (CAFs) are abundant in most solid tumors and display pro-tumorigenic and pro-metastatic functions, but extensive molecular diversity among CAFs has yielded contradictory results in previous attempts to target this population. Therefore, there is a need to identify markers of CAF subpopulations that promote or inhibit metastasis and functionally characterize them to understand their contributions during tumor progression. Our work identifies a population of CAFs, marked by expression of the matricellular protein periostin, that remodel the ECM to promote the escape of cancer cells into lymphatic vessels thereby driving colonization of proximal lymph nodes.

cancer biology↗