Tspan9 Induces EMT and Promotes Osteosarcoma Metastasis via Activating FAK-Ras-ERK1/2 Pathway

Roles and inhibitors of FAK in cancer: current advances and future directions

Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that exhibits high expression in various tumors and is associated with a poor prognosis. FAK activation promotes tumor growth, invasion, metastasis, and angiogenesis via both kinase-dependent and kinase-independent pathways. Moreover, FAK is crucial for sustaining the tumor microenvironment. The inhibition of FAK impedes tumorigenesis, metastasis, and drug resistance in cancer. Therefore, developing targeted inhibitors against FAK presents a promising therapeutic strategy. To date, numerous FAK inhibitors, including IN10018, defactinib, GSK2256098, conteltinib, and APG-2449, have been developed, which have demonstrated positive anti-tumor effects in preclinical studies and are undergoing clinical trials for several types of tumors. Moreover, many novel FAK inhibitors are currently in preclinical studies to advance targeted therapy for tumors with aberrantly activated FAK. The benefits of FAK degraders, especially in terms of their scaffold function, are increasingly evident, holding promising potential for future clinical exploration and breakthroughs. This review aims to clarify FAK's role in cancer, offering a comprehensive overview of the current status and future prospects of FAK-targeted therapy and combination approaches. The goal is to provide valuable insights for advancing anti-cancer treatment strategies.

The role of Tetraspanins in digestive system tumor development: update and emerging evidence

Digestive system malignancies, including cancers of the esophagus, pancreas, stomach, liver, and colorectum, are the leading causes of cancer-related deaths worldwide due to their high morbidity and poor prognosis. The lack of effective early diagnosis methods is a significant factor contributing to the poor prognosis for these malignancies. Tetraspanins (Tspans) are a superfamily of 4-transmembrane proteins (TM4SF), classified as low-molecular-weight glycoproteins, with 33 Tspan family members identified in humans to date. They interact with other membrane proteins or TM4SF members to form a functional platform on the cytoplasmic membrane called Tspan-enriched microdomain and serve multiple functions including cell adhesion, migration, propagation and signal transduction. In this review, we summarize the various roles of Tspans in the progression of digestive system tumors and the underlying molecular mechanisms in recent years. Generally, the expression of CD9, CD151, Tspan1, Tspan5, Tspan8, Tspan12, Tspan15, and Tspan31 are upregulated, facilitating the migration and invasion of digestive system cancer cells. Conversely, Tspan7, CD82, CD63, Tspan7, and Tspan9 are downregulated, suppressing digestive system tumor cell metastasis. Furthermore, the connection between Tspans and the metastasis of malignant bone tumors is reviewed. We also summarize the potential role of Tspans as novel immunotherapy targets and as an approach to overcome drug resistance. Finally, we discuss the potential clinical value and therapeutic targets of Tspans in the treatments of digestive system malignancies and provide some guidance for future research.

Spatial Transcriptomic Profiling of Tetraspanins in Stage 4 Colon Cancer from Primary Tumor and Liver Metastasis

Stage 4 colon cancer (CC) presents a significant global health challenge due to its poor prognosis and limited treatment options. Tetraspanins, the transmembrane proteins involved in crucial cancer processes, have recently gained attention as diagnostic markers and therapeutic targets. However, their spatial expression and potential roles in stage 4 CC tissues remain unknown. Using the GeoMx digital spatial profiler, we profiled all 33 human tetraspanin genes in 48 areas within stage 4 CC tissues, segmented into immune, fibroblast, and tumor compartments. Our results unveiled diverse gene expression patterns across different primary tumor sub-regions. CD53 exhibited distinct overexpression in the immune compartment, hinting at a potential role in immune modulation. TSPAN9 was specifically overexpressed in the fibroblast compartment, suggesting involvement in tumor invasion and metastasis. CD9, CD151, TSPAN1, TSPAN3, TSPAN8, and TSPAN13 displayed specific overexpression in the tumor compartment, indicating potential roles in tumor growth. Furthermore, our differential analysis revealed significant spatial changes in tetraspanin expression between patient-matched stage 4 primary CC and metastatic liver tissues. These findings provide spatially resolved insights into the expression and potential roles of tetraspanins in stage 4 CC progression, proposing their utility as diagnostic markers and therapeutic targets. Understanding this landscape is beneficial for tailoring therapeutic strategies to specific sub-tumor regions in the context of stage 4 CC and liver metastasis.

Focal adhesion kinase (FAK): its structure, characteristics, and signaling in skeletal system

Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase and distributes important regulatory functions in skeletal system. Mesenchymal stem cell (MSC) possesses significant migration and differentiation capacity, is an important source of distinctive bone cells production and a prominent bone development pathway. MSC has a wide range of applications in tissue bioengineering and regenerative medicine, and is frequently employed for hematopoietic support, immunological regulation, and defect repair, although current research is insufficient. FAK has been identified to cross-link with many other keys signaling pathways in bone biology and is considered as a fundamental "crossroad" on the signal transduction pathway and a "node" in the signal network to mediate MSC lineage development in skeletal system. In this review, we summarized the structure, characteristics, cellular signaling, and the interactions of FAK with other signaling pathways in the skeletal system. The discovery of FAK and its mediated molecules will lead to a new knowledge of bone development and bone construction as well as considerable potential for therapeutic use in the treatment of bone-related disorders such as osteoporosis, osteoarthritis, and osteosarcoma.

LncRNA KIAA0087 suppresses the progression of osteosarcoma by mediating the SOCS1/JAK2/STAT3 signaling pathway

Long noncoding RNAs (lncRNAs), widely expressed in mammalian cells, play pivotal roles in osteosarcoma (OS) progression. Nevertheless, the detailed molecular mechanisms of lncRNA KIAA0087 in OS remain obscure. Here, the roles of KIAA0087 in OS tumorigenesis were investigated. KIAA0087 and miR-411-3p levels were detected by RT-qPCR. Malignant properties were assessed by CCK-8, colony formation, flow cytometry, wound healing, and transwell assays. SOCS1, EMT, and JAK2/STAT3 pathway-related protein levels were measured by western blotting. Direct binding between miR-411-3p and KIAA0087/SOCS1 was validated by a dual-luciferase reporter, RIP, and FISH assays. In vivo growth and lung metastasis were evaluated in nude mice. The expression levels of SOCS1, Ki-67, E-cadherin, and N-cadherin in tumor tissues were measured by immunohistochemical staining. Downregulation of KIAA0087 and SOCS1 and upregulation of miR-411-3p were found in OS tissues and cells. Low expression of KIAA0087 was associated with a poor survival rate. Forced expression of KIAA0087 or miR-411-3p inhibition repressed the growth, migration, invasion, EMT, and activation of the JAK2/STAT3 pathway and triggered apoptosis of OS cells. However, the opposite results were found with KIAA0087 knockdown or miR-411-3p overexpression. Mechanistic experiments indicated that KIAA0087 enhanced SOCS1 expression to inactivate the JAK2/STAT3 pathway by sponging miR-411-3p. Rescue experiments revealed that the antitumor effects of KIAA0087 overexpression or miR-411-3p suppression were counteracted by miR-411-3p mimics or SOCS1 inhibition, respectively. Finally, in vivo tumor growth and lung metastasis were inhibited in KIAA0087-overexpressing or miR-411-3p-inhibited OS cells. In summary, the downregulation of KIAA0087 promotes the growth, metastasis, and EMT of OS by targeting the miR-411-3p-mediated SOCS1/JAK2/STAT3 pathway.

Identifying diagnostic markers and constructing a prognostic model for small-cell lung cancer based on blood exosome-related genes and machine-learning methods

Background

Small-cell lung cancer (SCLC) usually presents as an extensive disease with a poor prognosis at the time of diagnosis. Exosomes are rich in biological information and have a powerful impact on tumor progression and metastasis. Therefore, this study aimed to screen for diagnostic markers of blood exosomes in SCLC patients and to build a prognostic model.

Methods

We identified blood exosome differentially expressed (DE) RNAs in the exoRBase cohort and identified feature RNAs by the LASSO, Random Forest, and SVM-REF three algorithms. Then, we identified DE genes (DEGs) between SCLC tissues and normal lung tissues in the GEO cohort and obtained exosome-associated DEGs (EDEGs) by intersection with exosomal DEmRNAs. Finally, we performed univariate Cox, LASSO, and multivariate Cox regression analyses on EDEGs to construct the model. We then compared the patients' overall survival (OS) between the two risk groups and assessed the independent prognostic value of the model using receiver operating characteristic (ROC) curve analysis.

Results

We identified 952 DEmRNAs, 210 DElncRNAs, and 190 DEcircRNAs in exosomes and identified 13 feature RNAs with good diagnostic value. Then, we obtained 274 EDEGs and constructed a risk model containing 7 genes (TBX21, ZFHX2, HIST2H2BE, LTBP1, SIAE, HIST1H2AL, and TSPAN9). Low-risk patients had a longer OS time than high-risk patients. The risk model can independently predict the prognosis of SCLC patients with the areas under the ROC curve (AUCs) of 0.820 at 1 year, 0.952 at 3 years, and 0.989 at 5 years.

Conclusions

We identified 13 valuable diagnostic markers in the exosomes of SCLC patients and constructed a new promising prognostic model for SCLC.

Convallatoxin suppresses osteosarcoma cell proliferation, migration, invasion, and enhances osteogenic differentiation by downregulating parathyroid hormone receptor 1 (PTHR1) expression and inactivating Wnt/β-catenin pathway

Osteosarcoma (OS) is the most common primary malignant bone tumor in children and adolescents. Convallatoxin, a natural cardiac glycoside, exhibits potent anti-tumor activities. Literature has confirmed that PTHR1 is highly expressed in OS tissues and cells and downregulation of PTHR1 could decrease the invasion and growth of OS cells and increase tumor differentiation. In addition, PTHR1 could activate Wnt signaling pathway to promote the malignant functions of OS. In the present study, MG63 and U2OS cells were treated with 0, 12.5, 25, and 50 nM convallatoxin in order to elucidate the precise function of convallatox on the malignant behaviors of OS cells. Moreover, MG63 and U2OS cells treated with convallatoxin were transfected with Ov-PTHR1 or sh-DKK1, aiming to explore whether convallatoxin impeded the malignant progression of OS by modulating PTHR1 and Wnt/β-catenin pathway. CCK-8, wound healing and transwell assays were employed to assess the proliferation, migration, and invasion of OS cells. Differentiation markers (collagen 1, osteopontin, RANKL, Runx2, osteocalcin) were measured to evaluate OS cell differentiation. Results illuminated that convallatoxin suppressed proliferation, migration, and invasion as well as promoted osteogenic differentiation of OS cells. Besides, convallatoxin inhibited PTHR1 expression and inactivated Wnt/β-catenin pathway and PTHR1 overexpression activated Wnt/β-catenin pathway. Furthermore, PTHR1 overexpression or DKK1 knockdown reversed the suppressing effects of convallatoxin on OS cell proliferation, migration, and invasion, as well as the enhancing effect of convallatoxin on OS cell osteogenic differentiation. Collectively, convallatoxin may repress the malignant progression of OS by blocking PTHR1 and Wnt/β-catenin pathway.