Tumor physical microenvironment contributes greatly to the response of tumor cells. However, the mechanism of how extracellular substrate rigidity remodels colorectal cancer (CRC) cell fate and affects CRC progression remains elusive. Here, we show that F-actin regulator KIAA1211, also known as Capping protein inhibiting regulator of actin dynamics (CRAD), negatively correlates with CRC progression, stemness, and metastasis. Mechanistically, decreased CRAD in soft substrates induces Yes-associated protein (YAP) retention in the cytoplasm, restoring the repression effect on stemness markers NANOG and OCT4, thereby promoting CRC stemness and metastasis. Furthermore, CRAD deficiency promotes colorectal tumor cell softening and regulates epithelial-mesenchymal transition (EMT) states, contributing to its metastasis potential. Clinically, CRAD expression is correlated with malignant degrees and metastasis in CRC patients. Our work uncovers a role of CRAD in anticancer and mechanical signal transduction of the extracellular matrix in CRC.
The role of methyltransferase-like 3 (METTL3), which participates in catalyzing N-methyladenosine (m6A) RNA modification, in gastric cancer (GC) is unclear. Here, we found that METTL3 was overexpressed in human GC. Functionally, we verified that METTL3 promoted tumor cell proliferation and angiogenesis through a series of phenotypic experiments. Subsequently, ADAMTS9 was identified as the downstream effector of METTL3 in GC, which could be degraded by the YTHDF2-dependent pathway. Finally, the data suggested that METTL3 might facilitate GC progression through the ADAMTS9-mediated PI3K/AKT pathway. Our study unveiled the fundamental mechanisms of METTL3 in GC progression. The clinical value of METTL3 in GC deserves further exploration.
Radiation is a curative treatment for localized prostate cancer (PCa). Unfortunately, radiotherapeutic efficacy is often diminished when patients develop more aggressive or metastatic phenotypes. Recent studies have demonstrated that extracellular vesicles participate in cancer therapeutic resistance by delivering small bioactive molecules, such as small non‐coding RNAs. Here, we show that stromal cell‐derived small extracellular vesicles (sEVs) facilitate the radioresistance of PCa cells by transporting interleukin‐8 (IL‐8). Indeed, prostatic stromal cells secrete more IL‐8 than AR‐positive PCa cells, which can be accumulated in sEVs. Intriguingly, the uptake of stromal cells‐derived sEVs by radiosensitive PCa cells enhanced their radioresistance, which could be attenuated by silencing CXCL8 in stromal cells or inhibiting its receptor CXCR2 in PCa cells. sEV‐mediated radioresistance has been validated in zebrafish and mouse xenograft tumours. Mechanistically, the uptake of stromal sEVs triggers the AMPK‐activated autophagy pathway in PCa cells under the irradiation condition. Consequently, inactivating AMPK efficiently resensitized radiotherapy either by utilizing an AMPK inhibitor or silencing AMPKα in PCa cells. Furthermore, chloroquine (CQ), a lysosomal inhibitor, sufficiently resensitized radiotherapy via blockade of autophagolysosome fusion, leading to autophagosome accumulation in PC cells. Collectively, these results suggest that stromal cells enhance the radioresistance of PCa cells mainly through sEVs that deliver IL‐8.
1 February 2022 in International Immunopharmacology
Antibody-drug conjugates (ADC), a combination of cytotoxic drugs and antibodies, have emerged as a rising star in cancer therapy. Disitamab vedotin (RC48), a novel ADC targeting human epidermal growth factor receptor 2 (HER2), is currently being explored in a variety of malignancies. Compared with conventional HER2-targeting agents, RC48 is characterized by a wider therapeutic window and less toxicity to normal tissues. In this review, we will analyze the structural elements and mechanisms of RC48. Besides, we provide a landscape on the progression of RC48 in common malignancies, focusing on RC48 in gastric or gastroesophageal junction cancer, and a brief overview of urothelial, breast and other cancers (e.g., gynecological cancer, biliary tract cancer, non-small cell lung cancer and myometrial invasive bladder cancer). Finally, we will also discuss future challenges in the development of RC48 and future directions to improve efficacy.
1 January 2021 in Oxidative Medicine and Cellular Longevity
Breast cancer is the most common cause of malignancy and cancer‐related morbidity and death worldwide that requests effective and safe chemotherapy. Evaluation of metallodrug‐based anticancer agents and statins as chemotherapeutics with fewer side effects is a largely unexplored research field. Synthesis and characterization of the ruthenium‐fluvastatin complex were achieved using multiple spectroscopic techniques and thus further examined to evaluate its chemotherapeutic prospects in both MDA‐MB‐231 and MCF‐7 cancer lines and eventually in vivo models of DMBA‐induced mammary carcinogenesis in rodents. Our studies indicate that the metal and ligand chelation was materialized by the ligand’s functional groups of carbonyl (=O) oxygen and hydroxyl (‐OH), and the complex has been observed to be crystalline and able to chelate with CT‐DNA. The complex was able to reduce cell proliferation and activate apoptotic events in breast carcinoma cell lines MCF‐7 and MDA‐MB‐231. In addition, the complex was able to modify p53 expressions to interfere with apoptosis in the carcinoma of the breast, stimulated by the intrinsic apoptotic path assisted by Bcl2 and Bax in vivo, yet at the same point, controlling the PI3K/Akt/mTOR/VEGF pathway, as obtained from western blotting, correlates with the MMP9‐regulated tumor mechanisms. Our research reveals that ruthenium‐fluvastatin chemotherapy may disrupt, rescind, or interrupt breast carcinoma progression by modifying intrinsic apoptosis as well as the antiangiogenic cascade, thereby taking the role of a potential candidate in cancer therapy for the immediate future.