PON2 appears to sustain chemoresistance by affecting important mechanisms related to ROS detoxification, glucose metabolism, and anti-apoptotic signaling by affecting important mechanisms related to ROS detoxification, glucose metabolism, and anti-apoptotic signaling.
It is demonstrated that NAC1 may be a critical factor in the development of chemoresistance, offering a potential novel target for the treatment of CRC.
Tong-Fa Ju, Huicheng Jin, Rongchao Ying et al.· 0 citations
: Background: Rho GTPase-activating protein 40 (ARHGAP40), downregulated in various tumors, including basal cell carcinoma, has an unclear role in colorectal cancer (CRC). This study aimed to elucidate the function and clinical significance of ARHGAP40 in CRC. Methods: ARHGAP40 expression in CRC tissues was evaluated by immunohistochemistry and analyzed in relation to clinicopathological features and patient survival. Gain-and loss-of-function experiments were performed in CRC cell lines to assess cell proliferation, apoptosis, migration, and invasion. RNA sequencing, co-immunoprecipitation, Ras homolog gene family member A (RhoA) activation assays, and rescue experiments were conducted to explore the underlying mechanism. Results: ARHGAP40 expression was significantly decreased in CRC tissues and cell lines. Low ARHGAP40 expression was associated with poor differentiation ( p < 0.001), deeper tumor invasion ( p = 0.004), lymph node metastasis ( p < 0.001), advanced TNM stage ( p < 0.001), and unfavorable prognosis in patients with CRC ( p < 0.05). Functional experiments showed that ARHGAP40 overexpression suppressed CRC cell proliferation, migration, and invasion, while promoting apoptosis, whereas ARHGAP40 knockdown exerted opposite effects. Mechanistically, ARHGAP40 interacted with RhoA and negatively regulated its activation. Moreover, restoration of RhoA activity partially reversed the effects of ARHGAP40 overexpression on CRC cell proliferation and apoptosis. Conclusions: ARHGAP40 is downregulated in CRC, and its loss may contribute to tumor progression, possibly through dysregulation of RhoA activity.
Bin Lian, Na You, Jing-Yun Wang et al.· Biocell (Mendoza)· 0 citations
Osteosarcoma (OS) is a highly aggressive bone tumor with limited therapeutic options. As a key component of the N6‑methyladenosine (m6A) methyltransferase complex, KIAA1429 contributes to tumor progression; however, its role in OS remains unclear. For the present study, four human OS cell lines (MG63, 143B, U2OS and Saos‑2) and an osteoblast cell line (hFOB1.19) were cultured in vitro, and KIAA1429 was knocked down in 143B and U2OS cells. To evaluate functional effects, cell proliferation was assessed using a Cell Counting Kit‑8 assay, apoptosis was evaluated by flow cytometry, migration was assessed by Transwell assay and invasion was analyzed using a wound healing assay. Subsequently, ferroptosis was induced using erastin, and analyzed by western blotting, ELISA, C11‑BODIPY staining and m6A‑modified RNA immunoprecipitation‑quantitative PCR. In addition, actinomycin D was used to inhibit transcription and to assess mRNA stability. The interaction between KIAA1429 and solute carrier family 7 member 11 (SLC7A11) was validated using a dual‑luciferase reporter assay. Furthermore, a xenograft model was established in BALB/c nude mice to assess tumor growth and ferroptosis markers, and tumor histology and proliferation were examined using hematoxylin and eosin staining and immunohistochemistry. The results revealed that KIAA1429 was significantly upregulated in OS cells, whereas its knockdown markedly suppressed malignant cellular behaviors. Downregulation of KIAA1429 also enhanced erastin‑induced ferroptosis. Mechanistically, KIAA1429 knockdown reduced m6A modification and decreased the stability of SLC7A11 mRNA, leading to its downregulation. Rescue experiments demonstrated that SLC7A11 overexpression reversed the effects of KIAA1429 knockdown on ferroptosis and malignant phenotypes. In vivo, KIAA1429 knockdown inhibited tumor growth and promoted ferroptosis, effects that were reversed by SLC7A11 overexpression. In conclusion, KIAA1429 knockdown may suppress OS progression by inhibiting m6A‑dependent SLC7A11 expression, thereby promoting ferroptosis. Targeting the KIAA1429/SLC7A11 axis may thus represent a promising therapeutic strategy for OS.
Hui Zeng, Yunyan Zhong, Dingbiao Zeng et al.· International Journal of Onc...· 0 citations
BACKGROUND
Gastric cancer (GC) remains one of the leading causes of cancer-related mortality globally and is associated with poor patient prognosis, which highlights an urgent need to identify effective biomarkers and therapeutic targets. N6-methyladenosine (m6A) modification and its reader proteins play a crucial role in tumorigenesis. Insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) participates in carcinogenesis and serves as a reader of m6A. However, its exact function and the underlying molecular mechanisms in the progression of GC remain unknown.
AIM
To investigate the role of IGF2BP1 in the progression of GC.
METHODS
The IGF2BP1 expression in GC tissues was assessed via immunohistochemistry and correlated with clinicopathological characteristics. Gain-of-function and loss-of-function experiments were performed to explore the functional roles of IGF2BP1 and its potential downstream target in GC cells and a nude mouse xenograft model. Cell proliferation, migration, and invasion were assessed using cell counting kit-8, wound-healing, and Transwell assays. RNA sequencing, methylated RNA immunoprecipitation quantitative polymerase chain reaction, and dual-luciferase reporter assays were conducted to elucidate the molecular mechanisms involved.
RESULTS
The IGF2BP1 was significantly upregulated in GC tissues and was positively associated with lymph node metastasis and poor overall survival. Functionally, IGF2BP1 knockdown inhibited GC cell proliferation, migration, and invasion in vitro and attenuated tumor growth in vivo . Integrated multi-omics analysis identified heparan sulfate 6-O-sulfotransferase 2 (HS6ST2) as a key downstream target of IGF2BP1. IGF2BP1 recognized and bound to m6A-modified sites within HS6ST2 mRNA, thereby enhancing its stability in an m6A-dependent manner. Rescue experiments confirmed that HS6ST2 mediated the oncogenic effects of IGF2BP1. Additionally, HS6ST2 knockdown inhibited the malignant characteristics of GC cells and triggered apoptosis, which was associated with inactivation of the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway.
CONCLUSION
These findings demonstrated that IGF2BP1 drives GC progression by stabilizing HS6ST2 mRNA via m6A modification. The IGF2BP1/HS6ST2 axis may serve as a potential prognostic biomarker and therapeutic intervention for GC.
Lu Liu, Yi-jing Zhou, Yue Xu et al.· World Journal of Gastrointes...· 0 citations
Osteosarcoma (OS) is the most common primary malignant bone tumor in children, comprising approximately 3% of all childhood cancers. Metastatic OS remains a clinical challenge largely due to pulmonary metastases, the main cause of death in these patients. Gemcitabine (GCB) alone or in combination with docetaxel, has been recommended as a second line therapy for relapsed OS, though its efficacy remains modest. We have previously demonstrated phosphorylated Heat Shock Protein 27 (HSP27) as a potential biomarker of chemotherapy-induced autophagy response in OS. In addition, HSP27 has been implicated in the regulation of mitophagy, the selective autophagic process targeting mitochondria. Thus, the purpose of our studies is to evaluate the role of Hsp27 in regulating mitophagy in osteosarcoma (OS) and to determine whether it influences cellular sensitivity to gemcitabine. Methods: Human OS cell lines LM7 and CCH-OS-D were used for the in-vitro studies. Mitophagy activity under basal conditions or following GCB treatment was assessed by immunoblot analysis of PINK1 and Parkin expression. In parallel, total Hsp27 and phosphorylated Hsp27 (Ser82) levels were assessed by immunoblotting. Additionally, fluorescence-based mitophagy detection assay was conducted in the OS cells under basal conditions and following GCB treatment. To determine whether mitophagy activation depends on Hsp27, LM7 cells with stable Hsp27 knockdown (LM7 Hsp27 KD) were generated via shRNA transfection. Knockdown efficiency was confirmed by immunoblot analysis of Hsp27 expression. Mitophagy was then evaluated by measuring PINK1 and Parkin levels by immunoblotting. To determine the impact of HSP27 depletion on GCB efficacy, LM7 Hsp27 KD cells were treated with GCB, and the apoptotic signaling was assessed by immunoblotting for cleaved PARP1 and cleaved caspase 3, while cell viability was monitored using the Incucyte system. Results: LM7 cells showed higher basal mitophagy and Hsp27 activity compared to CCH-OS-D as evidenced by elevated PINK1 and Parkin levels and an increased Phospho-Hsp27 ratio. In CCH-OS-D these levels were low to undetectable, limiting assessment of HSP27-dependent effect in this model. GCB further induced mitophagy and Hsp27 activation in LM7 cells, whereas no comparable effect was observed in CCH-OS-D cells, as confirmed by immunoblotting and fluorescent-based mitophagy assay. Knocking down Hsp27 in LM7 reduced both total and Phospho-Hsp27 levels and was accompanied by decreased PINK1 and Parkin expression. Importantly, Hsp27 depletion increased GCB sensitivity, as demonstrated by increased cell death in Incucyte assay and augmented apoptotic signaling, reflected by higher levels of cleaved PARP1 and cleaved caspase 3 on immunoblotting. Conclusion: Hsp27 expression modulates both basal and GCB-induced mitophagy in OS. Hsp27-mediated mitophagy is associated with reduced GCB efficacy, suggesting that targeting Hsp27-regulated mitophagy may enhance therapeutic response.
Yan Zheng, Nancy Gordon, Ariana Anjer, Eugenie Kleinerman, Heping Wang. Hsp27 Mediates Sensitivity to Gemcitabine through Mitophagy Regulation in Osteosarcoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Breaking Barriers in the Fight against Rare Cancers; 2026 Jul 18-20; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2026;86(14_Suppl):Abstract nr A007.
Yan Zheng, Nancy Gordon, Ariana Anjer et al.· Cancer Research· 0 citations
Among adolescents worldwide, osteosarcoma (OS) is one of the most frequently occurring cancers. DSCAM-AS1, a recognized lncRNA, has been noted for its abnormal expression in the development of certain cancers, but its role in OS is still unclear. Quantification of DSCAM-AS1, miR-211-5p, and PDCD6 expression was carried out via qRT-PCR or western blotting in human osteosarcoma cell lines (HOS, MG63, U2OS, SaOS-2) and a normal osteoblastic cell line (hFOB 1.19) using quantitative real-time polymerase chain reaction (qRT-PCR) for RNA detection and western blotting for protein detection, respectively. Cellular proliferation, apoptosis, migration, and invasion in OS cell models were comprehensively evaluated through a combination of experimental approaches, including EdU incorporation assay, CFSE labeling coupled with flow cytometric analysis, as well as transwell invasion and migration assays. To shed light on the molecular mechanisms of interactions among pertinent RNA molecules, researchers conducted luciferase reporter assays, RNA pull-down experiments, and RIP assays. Expression of DSCAM-AS1, miR-211-5p, and PDCD6 was analyzed based on the GEO database, and their correlations were evaluated. The levels of DSCAM-AS1and PDCD6 were predominantly overexpressed, while miR-211-5p was apparently lowly expressed in OS cells. Functional loss-of-function experiments demonstrated that silencing (knockdown) of DSCAM-AS1 expression substantially diminished OS cell proliferation, migration, and invasion, while simultaneously promoting cellular apoptosis in vitro. Mechanistically. DSCAM-AS1 acted as an upstream factor for miR-211-5p and could increase the expression of miR-211-5p-targeted PDCD6. DSCAM-AS1 facilitated the advancement of OS by increasing PDCD6 levels through miR-211-5p sponging. This observation could shed light on a novel therapeutic target option for OS.
Qi Wang, Yunzheng Zhao, Long-Bao Shi et al.· Drug development research (P...· 0 citations