Knocking down Siglec-15 in osteosarcoma cells inhibits proliferation while promoting apoptosis and pyroptosis by targeting the Siglec-15/STAT3/Bcl-2 pathway

tRF-33-P4R8YP9LON4VDP inhibits gastric cancer progression via modulating STAT3 signaling pathway in an AGO2-dependent manner

It has been demonstrated that tRNA-derived small RNAs (tsRNAs) perform essential functions in the pathophysiology of cancer. In this study, we focused on the possible mechanisms of tRF-33-P4R8YP9LON4VDP (tRF-33) underlying the development of gastric malignancy. In total, 454 tissue samples with different gastric mucosal lesions were collected. The tRF-33 expression level in different cohorts was determined, and its value for diagnostic efficiency and prognosis evaluation were assessed. Cell proliferation assays, Transwell assay, flow cytometry, and xenotransplantation model were used to evaluate its effect on gastric cancer cells. The molecular mechanism was verified by fluorescence in situ hybridization, dual luciferase assay, Western blot, and RNA binding protein immunoprecipitation. The results showed that the expression of tRF-33 exhibited a gradual modification from normal control samples to gastritis tissues, early and latent stage of gastric cancer tissues. Consequently, tRF-33 holds significant potential as a predictive and diagnostic biomarker for gastric malignancy. Over-expression of tRF-33 inhibited gastric cancer cell progression and metastatic viability, and induced cell apoptosis. Tumorigenicity in nude mice showed the suppressive characteristics of tRF-33. Mechanistic investigation revealed that tRF-33 exerted silencing on STAT3 mRNA via binding to AGO2. In conclusion, tRF-33 exhibited values in diagnosing gastric cancer and evaluating its prognosis, and suppressed tumor cell viability by inhibiting STAT3 signaling pathway. The schematic mechanisms underlying tRF-33 regulating gastric cancer occurrence. tRF-33 binds to AGO2 proteins and then negatively regulates STAT3 expression through targeting its 3'UTR. The downregulated expression of STAT3 results in the decrease of STAT3 and p-STAT3 and further blocks the transcription of the downstream genes and finally inhibits the gastric cancer occurrence. MMP-9, matrix metalloproteinase-9; Bcl-2, B-cell lymphoma-2; STAT3, signal transducer and activator of transcription 3; UTR, untranslated region.

The role of programmed cell death in osteosarcoma: From pathogenesis to therapy

Osteosarcoma (OS) is a prevalent bone solid malignancy that primarily affects adolescents, particularly boys aged 14-19. This aggressive form of cancer often leads to deadly lung cancer due to its high migration ability. Experimental evidence suggests that programmed cell death (PCD) plays a crucial role in the development of osteosarcoma. Various forms of PCD, including apoptosis, ferroptosis, autophagy, necroptosis, and pyroptosis, contribute significantly to the progression of osteosarcoma. Additionally, different signaling pathways such as STAT3/c-Myc signal pathway, JNK signl pathway, PI3k/AKT/mTOR signal pathway, WNT/β-catenin signal pathway, and RhoA signal pathway can influence the development of osteosarcoma by regulating PCD in osteosarcoma cell. Therefore, targeting PCD and the associated signaling pathways could offer a promising therapeutic approach for treating osteosarcoma.

Identification of therapeutic targets and prognostic biomarkers in the Siglec family of genes in tumor immune microenvironment of sarcoma

Sarcomas (SARC) are a highly heterogeneous cancer type that is prone to recurrence and metastasis. Numerous studies have confirmed that Siglecs are involved in immune signaling and play a key role in regulating immune responses in inflammatory diseases and various cancers. However, studies that systematically explore the therapeutic and prognostic value of Siglecs in SARC patients are very limited. The online databases GEPIA, UALCAN, TIMER, The Kaplan-Meier Plotter, GeneMANIA, cBioPortal, and STING were used in this study. IHC staining was performed on the collected patient tissues, and clinical data were statistically analyzed. The transcript levels of most Siglec family members showed a high expression pattern in SARC. Compared with normal tissues, Siglec-5, Siglec-10, and Siglec-12 were abnormally highly expressed in tumor tissues. Importantly, Siglec-15 was significantly associated with poor prognosis. Functional enrichment analysis showed that the Siglec family was mainly enriched in hematopoietic cell lineages. The genes associated with molecular mutations in the Siglec family were mainly TP53 and MUC16, among which Siglec-2 and Siglec-15 were significantly associated with the survival of patients. The expression levels of all Siglec family members were significantly correlated with various types of immune cells (B cells, CD8 + T cells, CD4 + T cells, macrophages, neutrophils and dendritic cells). Furthermore, a significant correlation was found between the somatic copy number changes of all Siglec molecules and the abundance of immune infiltrates. Our study paints a promising vision for the development of immunotherapy drugs and the construction of prognostic stratification models by investigating the therapeutic and prognostic potential of the Siglec family for SARC.

Novel Siglec-15-Sia axis inhibitor leads to colorectal cancer cell death by targeting miR-6715b-3p and oncogenes

Siglecs are well known immunotherapeutic targets in cancer. Current checkpoint inhibitors have exhibited limited efficacy, prompting a need for novel therapeutics for targets such as Siglec-15. Presently, small molecule inhibitors targeting Siglec-15 are not explored alongside characterised regulatory mechanisms involving microRNAs in CRC progression. Therefore, a small molecule inhibitor to target Siglec-15 was elucidated in vitro and microRNA mediated inhibitor effects were investigated. Our research findings demonstrated that the SHG-8 molecule exerted significant cytotoxicity on cell viability, migration, and colony formation, with an IC50 value of approximately 20µM. SHG-8 exposure induced late apoptosis in vitro in SW480 CRC cells. Notably, miR-6715b-3p was the most upregulated miRNA in high-throughput sequencing, which was also validated via RT-qPCR. MiR-6715b-3p may regulate PTTG1IP, a potential oncogene which was validated via RT-qPCR and in silico analysis. Additionally, molecular docking studies revealed SHG-8 interactions with the Siglec-15 binding pocket with the binding affinity of -5.4 kcal/mol, highlighting its role as a small molecule inhibitor. Importantly, Siglec-15 and PD-L1 are expressed on mutually exclusive cancer cell populations, suggesting the potential for combination therapies with PD-L1 antagonists.

Prognostic value of Siglec-15 expression in patients with solid tumors: A meta-analysis

Background

Siglec-15 is expressed in a variety of cancers. However, the role of Siglec-15 in the prognosis of cancer patients remains controversial. Therefore, we conducted a meta-analysis to clarify the potential prognostic value of Siglec-15 in solid tumors.

Methods

The PubMed, Web of Science, Embase and CNKI databases were comprehensively searched to identify studies assessing the effect of Siglec-15 on the survival of cancer patients. Hazard ratios (HRs) with 95% confidence intervals (CIs) for overall survival (OS), progression-free survival (PFS) and disease-specific survival (DSS) from individual studies were evaluated.

Results

The data from 13 observational studies consisting of 1376 patients were summarized. Elevated baseline Siglec-15 expression was significantly correlated with poor OS (pooled HR = 1.28, 95% CI: 1.05-1.56; P = 0.013). However, high Siglec-15 expression predicted a significantly better DSS (pooled HR = 0.73 (95% CI: 0.57-0.94; P = 0.015) but not PFS (pooled HR = 1.49, 95% CI: 0.46-4.87; P=0.510). In addition, high Siglec-15 expression was not associated with PD-L1 (OR=0.64, 95% CI: 0.42-0.95; P = 0.028). High Siglec-15 expression was associated with male sex (OR = 1.39, 95% CI: 1.05-1.84; P = 0.022), larger tumor size (OR = 1.896, 95% CI: 1.26-2.9; P = 0.002), and advanced tumor-node-metastasis (TNM) stage (OR = 1.84; 95% CI: 1.19-2.84; P =0.006) in solid tumors.

Conclusions

This updated study suggested the expression of Siglec-15 is significantly associated with poor outcomes in human solid tumors, but further studies are needed to determine the prognostic value of Siglec-15 in solid tumors.