Publications by authors named "Meichun Cai"

During targeted treatment, oncogene-addicted tumor cells often evolve from an initial drug-sensitive state through a drug-tolerant persister bottleneck toward the ultimate emergence of drug-resistant clones. The molecular basis underlying this therapy-induced evolutionary trajectory has not yet been completely elucidated. Here, we employed a multifaceted approach and implicated the convergent role of transcription factor Yin Yang 1 (YY1) in the course of diverse targeted kinase inhibitors.

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  • Neuroendocrine bladder cancer (NEBC) is challenging to treat, and there's a growing interest in using immunotherapy, but its immunogenic profiles are not well-studied.
  • A comprehensive analysis of NEBC using various methods (genomic, transcriptomic, and single-cell RNA sequencing) revealed it generally has an inactive immune environment, despite high mutation rates; however, some mixed types show immune activity that could influence prognosis.
  • Findings suggest that while immune checkpoint inhibitors alone are not very effective for NEBC, combining immunotherapy with chemotherapy may improve treatment responses and offer new pathways for reducing mortality.
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Mitochondrial antiviral signaling protein (MAVS)-mediated cytosolic RNA sensing plays a central role in tumor immunogenicity. However, the effects of host MAVS signaling on antitumor immunity remain unclear. Here, we demonstrate that the host MAVS pathway supports tumor growth and impairs antitumor immunity, whereas MAVS deficiency in dendritic cells (DCs) promotes tumor-reactive CD8 T cell responses.

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Transcriptional dysregulation is a recurring pathogenic hallmark and an emerging therapeutic vulnerability in ovarian cancer. Here, we demonstrated that ovarian cancer exhibited a unique dependency on the regulatory machinery of transcriptional termination, particularly, cleavage and polyadenylation specificity factor (CPSF) complex. Genetic abrogation of multiple CPSF subunits substantially hampered neoplastic cell viability, and we presented evidence that their indispensable roles converged on the endonuclease CPSF3.

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Background: Ovarian clear cell carcinoma (OCCC) is a challenging disease due to its intrinsic chemoresistance. Immunotherapy is an emerging treatment option but currently impeded by insufficient understanding of OCCC immunophenotypes and their molecular determinants.

Methods: Whole-genome sequencing on 23 pathologically confirmed patients was employed to depict the genomic profile of primary OCCCs.

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  • Targeted cancer treatments often leave behind drug-tolerant persister (DTP) cells, which can evade dying despite the effectiveness of the drugs.
  • Researchers have found that an increase of the protein MCL1 helps these DTP cells survive by blocking apoptosis, particularly when targeted therapies disrupt MAPK signaling.
  • Combining molecular targeted agents with inhibitors of the PI3K-mTOR pathway can prevent the upregulation of MCL1, improving the chances of completely eradicating the cancer.*
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Co-stimulation signaling in various types of immune cells modulates immune responses in physiology and disease. Tumor necrosis factor receptor superfamily (TNFRSF) members such as CD40, OX40 and CD137/4-1BB are expressed on myeloid cells and/or lymphocytes, and they regulate antigen presentation and adaptive immune activities. TNFRSF agonistic antibodies have been evaluated extensively in preclinical models, and the robust antitumor immune responses and efficacy have encouraged continued clinical investigations for the last two decades.

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  • The study explores how inhibiting cyclin-dependent kinase 12 (CDK12) can affect ovarian cancer by targeting tumor cells directly and potentially enhancing immune responses to treatment.
  • Researchers developed a new oral compound, ZSQ836, which showed strong anticancer effects in lab and animal models while affecting genes related to DNA damage.
  • Interestingly, while ZSQ836 damaged cancer cells, it also inhibited T-cell activity, highlighting its dual effect of both suppressing tumor growth and weakening immune response, which may inform future drug development targeting CDK12.
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Müllerian tissue-specific oncogenes, prototyped by PAX8, underlie ovarian tumorigenesis and represent unique molecular vulnerabilities. Further delineating such lineage-dependency factors and associated therapeutic implications would provide valuable insights into ovarian cancer biology and treatment. In this study, we identified SOX17 as a new lineage-survival master transcription factor, which shared co-expression pattern with PAX8 in epithelial ovarian carcinoma.

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  • - GSDME is a newly identified player in pyroptosis (a form of programmed cell death) that may influence both tumor growth and immune responses, but details on how it's regulated are still unclear.
  • - Research revealed a positive correlation between GSDME levels and epithelial-mesenchymal transition (EMT) gene signatures in various human cancers, with key EMT factors (ZEB1/2) directly activating GSDME expression.
  • - The study suggests that high GSDME levels can lead to cell death and inflammation when cancer cells are treated with anti-cancer drugs, indicating that targeting GSDME could be a promising therapeutic strategy for certain types of cancer.
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BET bromodomain inhibitors (BETi) are promising therapeutic regimens for epithelial ovarian cancer (EOC). However, early-stage clinical trials indicate that drug tolerance may limit their anti-tumor efficacy. Here, we show that JQ1-refractory EOC cells acquire reversible resistance to BET inhibition and remain dependent on BRD4 function.

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Purpose: Next-generation sequencing (NGS)-based profiling of both urinary tumor DNA (utDNA) and circulating tumor DNA (ctDNA) shows promise for noninvasive detection and surveillance of urothelial bladder cancer (UBC). However, the analytical performance of these assays remains undefined in the real-world setting. Here, we sought to evaluate the concordance between tumor DNA (tDNA) profiling and utDNA or ctDNA assays using a UBC patient cohort from the intended-use population.

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  • The study evaluated the immune landscape in 109 cervical cancer patients both before and after chemotherapy to aid research on checkpoint inhibitors in this disease.
  • Researchers used immunohistochemistry and RNA sequencing to analyze various immune markers and found that the abundance of certain T cells correlated with PD-L1 expression.
  • The results suggested that while some patients had a robust immune response, chemotherapy could enhance this immune activity, indicating potential for future therapies using immune checkpoint inhibitors.*
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Direct quantification of exhausted T cells in human cancer is lacking, and its predictive value for checkpoint-based treatment remains poorly investigated. We sought to systematically characterize the pan-cancer landscape and molecular hallmarks of T-cell dysfunction for the purpose of precision immunotherapy. Here, we defined a transcriptional signature for T-cell exhaustion through analyzing differential gene expression between PD-1-high and PD-1-negative CD8 T lymphocytes from primary non-small cell lung cancer (NSCLC), followed by positive correlation tests with PDCD1 in TCGA lung carcinomas.

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We show that a non-Markovian behavior can appear in a type of Markovian multimeric channel. Such a channel consists of N independent subunits, and each subunit has at least one open state and more than one closed state. Suppose the open state of the channel is defined as M out of N subunits in the open state with N>M>0.

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Background: Ovarian clear cell carcinoma (OCCC) arises from endometriosis and represents a difficult-to-treat gynaecological malignancy, in part, because its spatial intratumour heterogeneity and temporal evolutionary trajectories have not been explicitly defined.

Methods: We performed whole-genome sequencing on six pathologically confirmed patients with OCCC. An R package named KataegisPortal was developed to identify and annotate loci of localised hypermutations.

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PAX8 is a prototype lineage-survival oncogene in epithelial ovarian cancer. However, neither its underlying pro-tumorigenic mechanisms nor potential therapeutic implications have been adequately elucidated. Here, we identified an ovarian lineage-specific PAX8 regulon using modified cancer outlier profile analysis, in which PAX8-FGF18 axis was responsible for promoting cell migration in an autocrine fashion.

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Comprehensive molecular characterization of myriad somatic alterations and aberrant gene expressions at personal level is key to precision cancer therapy, yet limited by current short-read sequencing technology, individualized catalog of complete genomic and transcriptomic features is thus far elusive. Here, we integrated second- and third-generation sequencing platforms to generate a multidimensional dataset on a patient affected by metastatic epithelial ovarian cancer. Whole-genome and hybrid transcriptome dissection captured global genetic and transcriptional variants at previously unparalleled resolution.

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  • KEAP1-NRF2 pathway alterations are common in lung adenocarcinomas and squamous cell carcinomas, but their biological and molecular characteristics are not well understood.
  • Research revealed that KEAP1/NRF2-mutant lung cancer has unique mutational signatures, poor tumor blood vessel formation, high hypoxic stress, and low immune cell presence.
  • The study also identified distinct molecular subsets among these tumors that could help develop better treatment strategies for lung cancer linked to KEAP1-NRF2 pathway changes.
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  • Researchers found that targeted cancer therapies can trigger a type of cell death called pyroptosis, alongside regular apoptosis, which is important for effective treatment.
  • In experiments, small-molecule inhibitors that target lung cancer oncogenes like KRAS, EGFR, and ALK were shown to activate pyroptotic cell death, involving the protein gasdermin E (GSDME).
  • This study highlights pyroptosis as a significant mechanism in cancer drug response, suggesting it could influence how future cancer therapies are developed and applied.
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Neuroendocrine bladder cancer is a relatively rare but often lethal malignancy, with cell of origin, oncogenomic architecture and standard treatment poorly defined. Here we performed comprehensive whole-genome and transcriptome sequencing on a unique cohort of genitourinary neuroendocrine neoplasms, mainly small cell carcinomas of the urinary bladder. The mutational landscape and signatures of neuroendocrine bladder cancer strikingly resembled those in conventional urothelial carcinoma, along with typically mixed histologies, supporting a common cellular origin.

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As an important intracellular signal, Ca^{2+} ions control diverse cellular functions. In this paper, we discuss the Ca^{2+} signaling with a two-dimensional model in which the inositol 1,4,5-trisphosphate (IP_{3}) receptor channels are distributed in clusters on the endoplasmic reticulum membrane. The wave failure at large Ca^{2+} diffusion coupling is discussed in detail in the model.

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  • Incidental prostate adenocarcinoma (IPCa) is often found during surgical evaluations for bladder cancer, but its clinical significance and relationship with bladder cancer (BCa) remain unclear.
  • In a study of 919 bladder cancer cases and a larger meta-analysis of 19,868 individuals, IPCa was found in 7.3% of patients, with a higher incidence in older individuals and differing prevalence rates between Asian and non-Asian countries.
  • Whole-exome sequencing showed that IPCa and BCa have distinct genetic origins and mutations, suggesting the two cancers develop independently and can be treated separately.
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Recent genomic analyses have revealed substantial tumor heterogeneity across various cancers. However, it remains unclear whether and how genomic heterogeneity is constrained during tumor evolution. Here, we sequence a unique cohort of multiple synchronous lung cancers (MSLCs) to determine the relative diversity and uniformity of genetic drivers upon identical germline and environmental background.

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Synchronous bilateral ovarian cancer (SBOC) represents a relatively frequent occurrence and clinically relevant diagnostic dilemma. Delineation of its clonal architecture, genetic heterogeneity, and evolutionary trajectories may have important implications for prognosis and management of patients with SBOC. Here, we describe the results of next-generation whole-exome or whole-genome sequencing of specimens from 12 SBOC cases and report that bilateral tumors from each individual display a comparable number of genomic abnormalities and similar mutational signatures of single-nucleotide variations.

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