使用全面的生物信息学分析和分子实验研究，利用泛癌数据，特别是胃癌（GC）数据来研究肌动蛋白原四（TPM4）的功能。我们使用UCSC Xena、癌症基因组图谱（TCGA）、基因型组织表达项目（GTEx）、TIMER2.0、GEPIA、cBioPortal、先导工具和UALCAN网站和数据库来提取TPM4的泛癌数据。将TPM4表达与预后，基因改变，表观遗传改变和免疫浸润相结合进行了研究。使用RNA22、miRWalk、miRDB、Starbase 2.0和Cytoscape来确定和构建GC中长链非编码RNA、microRNA和TPM4的调控网络。使用GSCALite，drug bank数据库和相连图谱（CMap）等数据进行药物敏感性分析。使用基因本体论（GO）、京都基因和基因组百科全书（KEGG）的富集分析、伤口愈合实验以及（Matrigel）转移实验来研究TPM4在GC中的生物功能。全面泛癌分析的结果表明，TPM4在大多数癌症中具有一定的诊断和预后价值。TPM4表达的改变（包括复制和深度突变）和表观遗传改变表明，TPM4表达与高浓度DNA甲基化抑制剂和RNA甲基化调节剂的表达相关。此外，TPM4表达与免疫细胞浸润、免疫检查点（ICP）基因表达、肿瘤突变负担（TMB）和微卫星不稳定性（MSI）相关。新抗原（NEO）也被发现影响其对免疫疗法的反应。发现了一个长链非编码RNA - microRNA - TPM4网络来调节GC的发展和进展。TPM4表达与多西他赛、5-氟尿嘧啶和八种小分子靶向药物的敏感性相关。基因功能富集分析表明，与TPM4共同表达的基因富集在细胞外基质（ECM）相关通路内。伤口愈合实验和（Matrigel）转移实验表明，TPM4促进了细胞迁移和侵袭。TPM4作为一个致癌基因，在GC中发挥生物学作用，可能通过ECM重塑来促进GC细胞的侵袭和迁移。TPM4是一个潜在的标记物，可用于泛癌治疗的诊断，治疗结果，免疫学，化疗和小分子药物靶向治疗，包括胃癌治疗。长链非编码RNA - microRNA - TPM4网络调节GC进展的机制。TPM4可能通过ECM重塑来促进GC细胞的侵袭和迁移。版权所有©2023年郭，赵，严，李，郭，党，沈，韩和罗。

To investigate the function of tropomyosin 4 (TPM4) using pan-cancer data, especially in gastric cancer (GC), using comprehensive bioinformatics analysis and molecular experiments.We used UCSC Xena, The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression Project (GTEx), TIMER2.0, GEPIA, cBioPortal, Xiantao tool, and UALCAN websites and databases for the extraction of pan-cancer data on TPM4. TPM4 expression was investigated with respect to prognosis, genetic alterations, epigenetic alterations, and immune infiltration. RNA22, miRWalk, miRDB, Starbase 2.0, and Cytoscape were used for identifying and constructing the regulatory networks of lncRNAs, miRNAs, and TPM4 in GC. Data from GSCALite, drug bank databases, and Connectivity Map (CMap) were used to analyze the sensitivity of drugs dependent on TPM4 expression. Gene Ontology (GO), enrichment analyses of the Kyoto Encyclopedia of Genes and Genomes (KEGG), wound healing assays, and (Matrigel) transwell experiments were used to investigate the biological functions of TPM4 in GC.The findings of the comprehensive pan-cancer analysis revealed that TPM4 has a certain diagnostic and prognosis value in most cancers. Alterations in the expression of TPM4, including duplications and deep mutations, and epigenetic alterations revealed that TPM4 expression is related to the expression of DNA methylation inhibitors and RNA methylation regulators at high concentrations. Besides, TPM4 expression was found to correlate with immune cell infiltration, immune checkpoint (ICP) gene expression, the tumor mutational burden (TMB), and microsatellite instability (MSI). Neoantigens (NEO) were also found to influence its response to immunotherapy. A lncRNA-miRNA -TPM4 network was found to regulate GC development and progression. TPM4 expression was related to docetaxel,5-fluorouracil, and eight small molecular targeted drugs sensitivity. Gene function enrichment analyses revealed that genes that were co-expressed with TPM4 were enriched within the extracellular matrix (ECM)-related pathways. Wound-healing and (Matrigel) transwell assays revealed that TPM4 promotes cell migration and invasion. TPM4, as an oncogene, plays a biological role, perhaps via ECM remodeling in GC.TPM4 is a prospective marker for the diagnosis, treatment outcome, immunology, chemotherapy, and small molecular drugs targeted for pan-cancer treatment, including GC treatment. The lncRNA-miRNA-TPM4network regulates the mechanism underlying GC progression. TPM4 may facilitate the invasion and migration of GC cells, possibly through ECM remodeling.Copyright © 2023 Guo, Zhao, Yan, Li, Guo, Dang, Shen, Han and Luo.