Biology subjects

Monavarian, M.

Publications and source records attributed to Monavarian, M..

6 recordsLinked to original sources

bioRxiv2025

Aging increases ovarian cancer growth, metastasis and immunosuppression that can be alleviated by inhibiting hedgehog signaling

Ovarian cancer incidence and mortality increase with age, yet how aging shapes tumor progression and the immune microenvironment remains poorly defined. Using orthotopic syngeneic models of distinct cellular origins (ovarian surface epithelial and fallopian tube-derived) in young versus aged mice, we show that aged hosts exhibit higher tumor burden, metastasis and ascites. Follicle depletion in young mice did not recapitulate these effects, indicating contributions beyond hormonal decline. Spatial transcriptomics revealed distinct age dependent intratumoral heterogeneity, with Hedgehog signaling enrichment in CD45+ cells from aged tumors, alongside elevated CD206+ tumor-associated macrophages and FoxP3+ regulatory T cells. Pharmacologic Hedgehog inhibition in aged mice suppressed tumor growth, reduced metastasis, and decreased CD206+ macrophages and FoxP3+ T cells while preserving CD8+T cells. In human ovarian cancer, Hedgehog activation correlated with immunosuppressive and immune checkpoint resistance signatures. We propose Hedgehog inhibition as an immunomodulatory strategy for Hedgehog activated or post menopausal ovarian cancer.

cancer biology↗

bioRxiv2025

ACTL6A regulates the Warburg effect through coordinated activation of AP-1 signaling in head and neck squamous cell carcinoma

ACTL6a is an essential component of SWI/SNF and expressed on the chromosome 3q26 cytoband, which is amplified in head and neck squamous cell carcinomas (HNSCC). While ACTL6A is emerging as an oncogene, its role as a treatment target and mechanisms of transcription factor induction remain unknown. Here, we show that ACTL6A expression is a mediator of the Warburg effect, with ACTL6A knockdown inducing mitochondrial dependency and significantly decreasing levels of aerobic glycolysis. These effects lead to near complete attenuation of hypoxic cell growth by blunting induction of HIF1 and HIF2 protein expression. They also sensitize treatment resistant HNSCC cells to the tumor killing effects of the complex I inhibitor IACS-010759 in vivo. Using ATAC-seq, we identify ACTL6A as a mediator of chromatin accessibility of AP-1 transcription factor sites and find that it regulates upstream MAPK signaling through induction of Ras and Galectin-1. These effects sensitize ACTL6A over-expressing cells to inhibition of glycolysis by MEK inhibitors. Our results link SWI/SNF subunit amplification with potentiation of MAPK signaling in HNSCC and provide a novel mechanism by which cancer cells drive aerobic glycolysis and reduce mitochondrial dependency. We leverage these findings to propose treatment strategies for hypoxic tumors with SWI/SNF subunit amplifications.

cancer biology↗

bioRxiv2023

Development of adaptive anoikis resistance promotes metastasis that can be overcome by CDK8/19 Mediator kinase inhibition

Anoikis resistance or evasion of cell death triggered by matrix detachment is a hallmark of cancer cell survival and metastasis. We show that repeated exposure to suspension stress followed by recovery under attached conditions leads to development of anoikis resistance. The acquisition of anoikis resistance is associated with enhanced invasion, chemoresistance, and immune evasion in vitro and distant metastasis in vivo. This acquired anoikis resistance is not genetic, persisting for a finite duration without detachment stress, but is sensitive to CDK8/19 Mediator kinase inhibition that can also reverse anoikis resistance. Transcriptomic analysis reveals that CDK8/19 kinase inhibition induces bidirectional transcriptional changes in both sensitive and resistant cells, disrupting the balanced reprogramming required for anoikis adaptation and resistance by reversing some resistance associated pathways and enhancing others. Both anoikis resistance and in vivo metastatic growth of ovarian cancers are sensitive to CDK8/19 inhibition, thereby providing a therapeutic opportunity to both prevent and suppress ovarian cancer metastasis.

cancer biology↗

bioRxiv2022

PVT1, a YAP1 dependent stress responsive lncRNA drives ovarian cancer metastasis and chemoresistance

Metastatic growth of ovarian cancer cells into the peritoneal cavity requires adaptation to various cellular stress factors to facilitate cell survival and growth. Here we demonstrate the role of PVT1, one such stress induced long non-coding RNA, in ovarian cancer growth and metastasis. PVT1 is an amplified and overexpressed lncRNA in ovarian cancer with strong predictive value for survival and response to targeted therapeutics. We find that expression of PVT1 is regulated by ovarian tumor cells in response to cellular stress, particularly loss of cell-cell contacts and changes in matrix rigidity occurring in a YAP1 dependent manner. Induction of PVT1 promotes tumor cell survival, growth, and migration. Conversely, reducing PVT1 levels robustly abrogates metastatic behavior and tumor cell dissemination in cell lines and syngeneic transplantation models in vivo. We find that reducing PVT1 causes widespread transcriptome changes leading to alterations in cellular stress response and metabolic pathways including doxorubicin metabolism, which directly impacts chemosensitivity. Together, these findings implicate PVT1 as a promising therapeutic target to suppress metastasis and avoid chemoresistance in ovarian cancer. SUMMARY BLURBPVT1 is a stress-responsive IncRNA regulated by YAP1, leading to increased ovarian cancer metastasis and chemoresistance, making PVT1 a promising therapeutic target.

cancer biology↗

bioRxiv2022

Reciprocal epigenetic Sox2 regulation by SMAD1-SMAD3 is critical for anoikis resistance and metastasis in cancer

Growth factors in the tumor environment are key regulators of cell survival and metastasis. Here we reveal, dichotomy between TGF-{beta} superfamily growth factors BMP and TGF-{beta}/activin, and their downstream SMAD effectors. Gene expression profiling uncovered Sox2 as a key signaling node regulated in an opposing manner by anoikis-promoting BMP2, 4 and 9, and anoikis-suppressing TGF-{beta} and activin A. We find that Sox2 repression by BMPs robustly inhibits intraperitoneal tumor burden and increases survival in multiple ovarian cancer models. Repression of Sox2 is driven by SMAD1 dependent histone H3K27me3 recruitment and DNA methylation at SOX2s promoter. Conversely, TGF-{beta} and activin A promote Sox2 expression, and anoikis resistance by SMAD3 mediated histone H3K4me3 recruitment. We find that balancing Sox2 levels is critical for anoikis, as transcriptomics reveals regulation of key cell death pathways. Moreover, BMP-driven SMAD1 signaling can override TGF-{beta} and activins effect on Sox2, which has clinical significance due to the high levels of TGF-{beta} we find in ovarian cancer patients. Together, our findings identify Sox2 as a contextual and contrastingly regulated key node, downstream of TGF-{beta} superfamily members controlling anoikis and metastasis in ovarian cancers. HighlightsO_LISox2 is a key node for anoikis resistance in cancer C_LIO_LISox2 is differentially regulated by TGF-{beta}/activin and BMPs in broad cancers C_LIO_LIBMP9 is a robust metastasis suppressor by lowering Sox2 C_LIO_LISox2 regulation is contextual, epigenetic and at the transcriptional level C_LI

cancer biology↗

bioRxiv2021

Decellularized Articular Cartilage Microparticles for Expansion of Mesenchymal Stem Cells and Zonal Regeneration of Articular Cartilage

IntroductionThe objective was to create multilayer cellular constructs using fetal or adult, decellularized articular cartilage in particulate form as microcarriers for expansion and fusion of mesenchymal stem cells (MSCs) to regenerate the stratified structure of articular cartilage. MethodsPorous microparticles (CMPs) generated from decellularized fetal or adult bovine articular cartilage were used as microcarriers for expansion of human MSCs. The CMP expanded MSCs (CMP-MSCs) were used to generate injectable hydrogels or preformed multilayer constructs for articular cartilage regeneration. In the injectable approach, CMP-MSCs were suspended in alginate gel, crosslinked with calcium chloride, and incubated in chondrogenic medium to generate an injectable regenerative construct. In the preformed approach, fetal or adult CMP-MSCs were suspended in a culture medium, allowed to settle sequentially by the force of gravity, and fused by incubation in chondrogenic medium to generate multilayer cell sheets. The constructs were characterized with respect to compressive modulus, cellularity, and expression of chondrogenic markers. ResultsHuman MSCs expanded on fetal or adult CMPs in basal medium maintained the expression of mesenchymal markers. The injectable CMP-MSCs hydrogels had significantly higher expression of chondrogenic markers and compressive modulus after four weeks incubation in chondrogenic medium compared to MSCs directly encapsulated in alginate gel; preformed CMP-MSCs cell sheets had significantly higher compressive modulus and expression of chondrogenic markers compared to MSCs in the pellet culture. ConclusionThe preformed cell sheet approach is potentially useful for creating multilayer constructs by sequential gravitational settling of CMP-MSCs to mimic the stratified structure of articular cartilage. Insight, Innovation, IntegrationThis work described a novel approach to recreate the zonal structure of articular cartilage. Human MSCs were expanded on porous microcarrier beads generated from decellularized fetal or adult bovine articular cartilage. The cell-seeded microbeads were fused by gravitational settling to form mono- or bi-layer cell sheets. The cell sheets were cultured in chondrogenic medium to regenerate the articular cartilage tissue. The in vitro regenerated tissue had higher compressive modulus and expression of chondrogenic markers compared to the MSC pellet culture.

bioengineering↗