BACKGROUND: Oral squamous cell carcinoma (OSCC) is a prevalent type of cancer with a high mortality rate in its late stages. One of the major challenges in OSCC treatment is the resistance to epidermal growth factor receptor (EGFR) inhibitors. Therefore, it is imperative to elucidate the mechanism underlying drug resistance and develop appropriate precision therapy strategies to enhance clinical efficacy. METHODS: To evaluate the efficacy of the combination of the Ca 2+ /calmodulin-dependent protein kinase II (CAMK2) inhibitor KN93 and EGFR inhibitors, we performed in vitro and in vivo experiments using two FAT atypical cadherin 1 ( FAT1 )-deficient (SCC9 and SCC25) and two FAT1 wild-type (SCC47 and HN12) OSCC cell lines. We assessed the effects of EGFR inhibitors (afatinib or cetuximab), KN93, or their combination on the malignant phenotype of OSCC in vivo and in vitro . The alterations in protein expression levels of members of the EGFR signaling pathway and SRY-box transcription factor 2 (SOX2) were analyzed. Changes in the yes-associated protein 1 (YAP1) protein were characterized. Moreover, we analyzed mitochondrial dysfunction. Besides, the effects of combination therapy on mitochondrial dynamics were also evaluated. RESULTS: OSCC with FAT1 mutations exhibited resistance to EGFR inhibitors treatment. The combination of KN93 and EGFR inhibitors significantly inhibited the proliferation, survival, and migration of FAT1 -mutated OSCC cells and suppressed tumor growth in vivo . Mechanistically, combination therapy enhanced the therapeutic sensitivity of FAT1 -mutated OSCC cells to EGFR inhibitors by modulating the EGFR pathway and downregulated tumor stemness-related proteins. Furthermore, combination therapy induced reactive oxygen species (ROS)-mediated mitochondrial dysfunction and disrupted mitochondrial dynamics, ultimately resulting in tumor suppression. CONCLUSION Combination therapy with EGFR inhibitors and KN93 could be a novel precision therapeutic strategy and a potential clinical solution for EGFR-resistant OSCC patients with FAT1 mutations.
Humans ; ErbB Receptors/metabolism* ; Mouth Neoplasms/metabolism* ; Cell Line, Tumor ; Animals ; Drug Resistance, Neoplasm/genetics* ; Cadherins/metabolism* ; Carcinoma, Squamous Cell/metabolism* ; Mice ; Mutation/genetics* ; Mice, Nude ; Protein Kinase Inhibitors/therapeutic use* ; Cetuximab/pharmacology* ; Afatinib/therapeutic use* ; Cell Proliferation/drug effects* ; Signal Transduction/drug effects*

The Kirsten rat sarcoma viral oncogene homolog ( KRAS ) mutation is one of the most prevalent activating alterations in cancer. It indicates a poor overall prognosis due to its highly invasive nature. Although several KRAS inhibitors have been developed in recent years, a significant clinical challenge has emerged as a substantial proportion of patients eventually develop resistance to these therapies. Therefore, identifying determinants of drug resistance is critical for guiding treatment strategies. This review provides a comprehensive overview of the mutation landscape and molecular mechanisms of KRAS activity in various cancers. Meanwhile, it summaries the progress and prospects of small molecule KRAS inhibitors undergoing clinical trials. Furthemore, this review explores potential strategies to overcome drug resistance, with the ultimate goal of steering toward patient-centric precision oncology in the foreseeable future.
Humans ; Drug Resistance, Neoplasm/drug effects* ; Proto-Oncogene Proteins p21(ras)/metabolism* ; Mutation/genetics* ; Neoplasms/genetics* ; Antineoplastic Agents/therapeutic use*

Objective To study the impacts of curcumin on the proliferation, migration and cisplatin (DDP) resistance of bladder cancer cells by regulating the liver kinase B1-AMP activated protein kinase-microtubule-associated protein 1 light chain 3 (LKB1-AMPK-LC3) signaling pathway. Methods Human bladder cancer cell line T24 was cultured in vitro, and its DDP resistant T24/DDP cells were induced by cisplatin (DDP). After treating T24 and T24/DDP cells with different concentrations of curcumin, the optimal concentration of curcumin was screened by MTT assay. T24 cells were randomly grouped into control group, curcumin group, metformin group, and combination group of curcumin and metformin. After treatment with curcumin and LKB1-AMPK activator metformin, the proliferation, autophagy, migration, and apoptosis of T24 cells in each group were detected by MTT assay, monodansylcadavrine (MDC) fluorescence staining, cell scratch assay, and flow cytometry, respectively. Western blot was used to detect the expression of proteins related to LKB1-AMPK-LC3 signaling pathway in T24 cells of each group. T24/DDP cells were randomly assigned into control group, curcumin group, metformin group, and combination group of curcumin and metformin. Cells were treated with curcumin and metformin according to grouping and treated with different concentrations of DDP simultaneously. Then, the effect of curcumin on the DDP resistance coefficient of T24/DDP cells was detected by MTT assay. T24/DDP cells were randomly grouped into control group, DDP group, combination groups of DDP and curcumin, DDP and metformin, DDP, curcumin and metformi. After treatment with DDP, curcumin, and metformin, the proliferation, autophagy, migration, apoptosis, drug resistance, and the expression of proteins related to LKB1-AMPK-LC3 signaling pathway in T24/DDP cells of each group were detected with the same methods. Results Compared with the control group, the activity of T24 cells, relative number of autophagosomes, migration rate, Phosphorylated-LKB1 (p-LKB1)/LKB1, Phosphorylated-AMPK (p-AMPK)/AMPK, LC3II/LC3I, and the DDP resistance coefficient of T24/DDP cells in the curcumin group were lower, and the apoptosis rate of T24 cells was higher; the changes in various indicators in the metformin group were opposite to those in the curcumin group. Compared with the curcumin group, the activity of T24 cells, relative number of autophagosomes, migration rate, p-LKB1/LKB1, p-AMPK/AMPK, LC3II/LC3I, and the DDP resistance coefficient of T24/DDP cells in the combination group of curcumin and metformin were higher, and the apoptosis rate of T24 cells was lower. Compared with the control group, there were no obvious changes in various indicators of T24/DDP cells in the DDP group. Compared with the control group and DDP group, the viability of T24/DDP cells, relative number of autophagosomes, migration rate, P-glycoprotein (P-gp) protein expression, p-LKB1/LKB1, p-AMPK/AMPK, and LC3II/LC3I in the combination group of DDP and curcumin were lower, and the apoptosis rate of T24/DDP cells was higher; the changes in the above indicators in the combination group of DDP and metformin were opposite to those in the combination group of DDP and curcumin. Compared with the combination group of DDP and curcumin, the viability of T24/DDP cells, relative number of autophagosomes, migration rate, P-gp protein expression, p-LKB1/LKB1, p-AMPK/AMPK, and LC3II/LC3I in the combination group of DDP, curcumin and metformin were higher, and the apoptosis rate of T24/DDP cells was lower. Conclusion Curcumin can reduce the activity of LKB1-AMPK-LC3 signaling pathway, thereby inhibiting autophagy, proliferation and migration of bladder cancer cells, promoting their apoptosis, and weakening their resistance to DDP.
Humans ; Cisplatin/pharmacology* ; Curcumin/pharmacology* ; Cell Proliferation/drug effects* ; Signal Transduction/drug effects* ; Protein Serine-Threonine Kinases/genetics* ; AMP-Activated Protein Kinases/metabolism* ; Drug Resistance, Neoplasm/drug effects* ; Urinary Bladder Neoplasms/pathology* ; Cell Line, Tumor ; Cell Movement/drug effects* ; AMP-Activated Protein Kinase Kinases ; Microtubule-Associated Proteins/metabolism* ; Apoptosis/drug effects* ; Antineoplastic Agents/pharmacology* ; Metformin/pharmacology* ; Autophagy/drug effects*

It has been popular and challenging to undertake researches on the delay of acquired resistance of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKI). As key cells for tumor initiation, cancer stem cells (CSC) play an important role in the process of resistance to EGFR-TKI. Although preliminary studies found that traditional Chinese medicine (TCM) could inhibit CSC properties and delay EGFR-TKI resistance, the specific molecular mechanism remains unclear. By summarizing the empirical syndrome treatment of EGFR-TKI resistance via TCM and combining recent researches on TCM intervention in CSC to delay EGFR-TKI resistance, this review discussed the potential molecular pathways and mechanisms of deceleration in resistance to EGFR-TKI by TCM via inhibiting CSC characteristics, in order to expand the research ideas of TCM in combination with targeted therapy.
Humans ; Neoplastic Stem Cells/metabolism* ; Drug Resistance, Neoplasm/drug effects* ; ErbB Receptors/genetics* ; Protein Kinase Inhibitors/therapeutic use* ; Medicine, Chinese Traditional ; Neoplasms/drug therapy* ; Animals ; Drugs, Chinese Herbal/therapeutic use*

Objective The aim of this study was to investigate the effect of p38 on stem cell maintenance of pancreatic cancer. Methods Human pancreatic cancer cells PANC-1 were treated with different concentrations of 5-fluorouracil(5-FU)(0.5×IC₅₀, IC₅₀, and 2×IC₅₀) for 24 hours, and VX-702 (p38 phosphorylation inhibitor) was added, and the cells were inoculated in 6-well culture dishes with ultra-low adhesion to observe the changes of sphere tumors. The expression levels of cyclin-dependent kinase 2(CDK2), cyclin B1 and D1, Octamer-binding transcription factor 4(OCT4), SRY-box transcription factor 2(SOX2), Nanog and p38 were measured by Western blot. The mRNA expression levels of p38, OCT4, Nanog and SOX2 were tested by RT-PCR. Cell cycle, apoptosis, and the proportion of CD44⁺CD133⁺PANC-1 cells were evaluated by flow cytometry. Results The results showed that 5-FU inhibited the formation of tumor spheres in PANC-1 cells, increased CD44⁺CD133⁺cell fragments, down-regulated the expression of OCT4, Nanog and SOX2, and inhibited the stemness maintenance of PANC-1 tumor stem cells. Phosphorylation of PANC-1 cells was inhibited by a highly selective p38 MAPK inhibitor, VX-702(p38 mitogen-activated protein kinase inhibitor), which had the same effect as 5-FU treatment. When VX-702 combined with 5-FU was used to treat PANC-1 cells, the therapeutic effect was enhanced. Conclusion p38 inhibitors decreased PANC-1 cell activity and increased cell apoptosis. p38 inhibitors inhibit the stemness maintenance of pancreatic cancer stem cells.
Humans ; Phosphorylation/drug effects* ; Cell Line, Tumor ; p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors* ; Neoplastic Stem Cells/metabolism* ; Drug Resistance, Neoplasm/drug effects* ; Fluorouracil/pharmacology* ; Pancreatic Neoplasms/pathology* ; Apoptosis/drug effects* ; SOXB1 Transcription Factors/genetics* ; Octamer Transcription Factor-3/genetics*

Lung cancer is the leading cause of cancer-related deaths worldwide, characterized by high incidence and mortality rates. The primary reasons for treatment failure in lung cancer patients are tumor invasion and drug resistance, particularly resistance to chemotherapeutic agents and epidermal growth factor receptor (EGFR) mutant targeted therapy, which considerably undermine the therapeutic outcomes for those with advanced lung cancer. Epithelial-mesenchymal transition (EMT) serves as a crucial biological process closely associated with physiological or pathological processes such as tissue embryogenesis, organogenesis, wound repair, and tumor invasion. Numerous studies have indicated that EMT, mediated through various signaling pathways, plays a pivotal role in the initiation, progression, and metastasis of lung cancer, while it is also closely associated with drug resistance in lung cancer cells. Therefore, research focusing on the molecular mechanisms and pathophysiology related to EMT can contribute to reversing drug resistance in drug treatment for lung cancer, thereby improving prognosis. This article reviews the progress in research on EMT in the invasion, metastasis, and drug resistance of lung cancer based on relevant domestic and international literature.
Humans ; Epithelial-Mesenchymal Transition/drug effects* ; Drug Resistance, Neoplasm ; Lung Neoplasms/physiopathology* ; Neoplasm Metastasis ; Neoplasm Invasiveness ; Animals ; Antineoplastic Agents/therapeutic use*

Non-small cell lung cancer (NSCLC) ranks among the most lethal malignancies worldwide. The clinical application of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) have successfully revolutionized the treatment paradigm for EGFR-mutant NSCLC, significantly prolonging progression-free survival and establishing EGFR-TKIs as the standard first-line therapy for advanced lung adenocarcinoma. However, acquired resistance remains a major obstacle to sustained clinical benefit, with mechanisms that are highly heterogeneous. A phenomenon of "oxidative stress compensation" is commonly observed in EGFR-TKIs-resistant cells, where in redox homeostasis, through the precise regulation of reactive oxygen species (ROS) generation and elimination, plays a pivotal role in maintaining the balance between tumor cell proliferation and apoptosis. This review aims to innovatively construct a theoretical framework describing how dynamic redox regulation influences resistance to third-generation EGFR-TKIs. It focuses on the multifaceted roles of ROS in both EGFR-dependent and EGFR-independent resistance mechanisms, and further explores therapeutic strategies that target ROS kinetic thresholds and antioxidant systems. These insights not only propose an innovative "metabolic checkpoint" regulatory pathway to overcome acquired resistance to third-generation EGFR-TKIs, but also lay a molecular foundation for developing the redox biomarker-based dynamic therapeutic decision-making systems, thereby facilitating a shift in NSCLC therapy from single-target inhibition toward multi-dimensional metabolic remodeling in the context of precision medicine.
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Humans ; Carcinoma, Non-Small-Cell Lung/genetics* ; ErbB Receptors/genetics* ; Drug Resistance, Neoplasm/drug effects* ; Lung Neoplasms/genetics* ; Oxidation-Reduction/drug effects* ; Homeostasis/drug effects* ; Protein Kinase Inhibitors/therapeutic use* ; Reactive Oxygen Species/metabolism* ; Animals

BACKGROUND: Lung cancer currently ranks first globally in both incidence and mortality. Pemetrexed (PMX) serves as a first-line treatment for lung adenocarcinoma (LUAD), but the patients often develop drug resistance during therapy. Milk exosome (mEXO) have the advantages of low immunogenicity, high tissue affinity, and low cost, and mEXO itself has anti-tumor effects. Hyaluronan (HA) naturally bind to CD44, a receptor which is highly expressed in LUAD tissues. This study aims to construct hyaluronan-modified milk exosome (HA-mEXO) and preliminarily investigate their molecular mechanisms for reversing PMX resistance through cellular experiments. METHODS: Exosomes were extracted from milk using high-speed centrifugation, and HA-mEXO was constructed. PMX-resistant A549 and PC-9 cell lines were treated with mEXO and HA-mEXO, respectively. CCK-8 assays, colony formation assays, Transwell assays, and flow cytometry were performed to evaluate proliferation, colony formation, migration, invasion, and apoptosis phenotypes in the treated resistant cell lines. Finally, transcriptomic sequencing, analysis, and cellular functional recovery experiments were conducted to investigate the mechanism by which HA-mEXO reverses PMX resistance in LUAD cells. RESULTS: The expression of CD44 in A549 and PC-9 LUAD drug-resistant cell lines was significantly higher than that in parental cells, and the uptake rate of HA-mEXO by drug-resistant cell lines was significantly higher than that of mEXO. Compared to the mEXO group, HA-mEXO-treated A549 and PC-9 resistant cells exhibited significantly reduced half maximal inhibitory concentration (IC50) values for PMX, markedly diminished clonogenic, migratory, and invasive capabilities, and a significantly increased proportion of apoptotic cells. Western blot analysis revealed that, compared to parental cells, A549 and PC-9 drug-resistant cells exhibited downregulated ZNF516 expression and upregulated ABCC5 expression. Immunofluorescence analysis revealed that HA-mEXO treatment downregulated ABCC5 expression in A549 and PC-9 drug-resistant cells compared to the PBS group, whereas co-treatment with HA-mEXO and ZNF516 knockdown showed no significant change in ABCC5 expression. CONCLUSIONS HA-mEXO carrying ZNF516 suppress ABCC5 expression, thereby enhancing the sensitivity of A549 and PC-9 LAUD drug-resistant cells to PMX.
Humans ; Hyaluronic Acid/chemistry* ; Drug Resistance, Neoplasm/drug effects* ; Exosomes/chemistry* ; Adenocarcinoma of Lung/genetics* ; Pemetrexed/pharmacology* ; Animals ; Lung Neoplasms/pathology* ; Milk/chemistry* ; Cell Proliferation/drug effects* ; Apoptosis/drug effects* ; Cell Line, Tumor ; Hyaluronan Receptors/metabolism*

Antibody-drug conjugate (ADC), a novel class of antineoplastic agents, combines tumor-specific targeting with potent cytotoxic activity. In recent years, ADC has achieved notable advances in the treatment of non-small cell lung cancer (NSCLC), particularly within therapeutic sequencing after failure of first-line therapy or the emergence of resistance. This paper will systematically review the efficacy and safety evidence of representative ADC in NSCLC, and further to discuss progress and challenges in ADC structural optimization, toxicity management, biomarker identification, and combination strategies, aiming to provide a comprehensive theoretical foundation and practical reference for clinical practice and future research.
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Humans ; Carcinoma, Non-Small-Cell Lung/drug therapy* ; Immunoconjugates/chemistry* ; Lung Neoplasms/drug therapy* ; Drug Resistance, Neoplasm/drug effects* ; Antineoplastic Agents/chemistry*

OBJECTIVE: To examine the mechanism of action of tanshinone II A (Tan II A) in promoting chemosensitization of osteosarcoma cells to cisplatin (DDP). METHODS: The effects of different concentrations of Tan II A (0-80 µ mol/L) and DDP (0-2 µ mol/L) on the proliferation of osteosarcoma cell lines (U2R, U2OS, 143B, and HOS) at different times were examined using the cell counting kit-8 and colony formation assays. Migration and invasion of U2R and U2OS cells were detected after 24 h treatment with 30 µ mol/L Tan II A, 0.5 µ mol/L DDP alone, and a combination of 10 µ mol/L Tan II A and 0.25 µ mol/L DDP using the transwell assay. After 48 h of treatment of U2R and U2OS cells with predetermined concentrations of each group of drugs, the cell cycle was analyzed using a cell cycle detection kit and flow cytometry. After 48 h treatment, apoptosis of U2R and U2OS cells was detected using annexin V-FITC apoptosis detection kit and flow cytometry. U2R cells were inoculated into the unilateral axilla of nude mice and then the mice were randomly divided into 4 groups of 6 nude mice each. The 4 groups were treated with equal volume of Tan II A (15 mg/kg), DDP (3 mg/kg), Tan II A (7.5 mg/kg) + DDP (1.5 mg/kg), and normal saline, respectively. The body weight of the nude mice was weighed, and the tumor volume and weight were measured. Cell-related gene and signaling pathway expression were detected by RNA sequencing and Kyoto Encyclopedia of Genes and Genomes pathway analysis. p38 MAPK signaling pathway proteins and apoptotic protein expressions were detected by Western blot. RESULTS: In vitro studies have shown that Tan II A, DDP and the combination of Tan II A and DDP inhibit the proliferation, migration and invasion of osteosarcoma cells. The inhibitory effect was more pronounced in the Tan II A and DDP combined treatment group (P<0.05 or P<0.01). Osteosarcoma cells underwent significantly cell-cycle arrest and cell apoptosis by Tan II A-DDP combination treatment (P<0.05 or P<0.01). In vivo studies demonstrated that the Tan II A-DD combination treatment group significantly inhibited tumor growth compared to the Tan II A and DDP single drug group (P<0.01). Additionally, we found that the combination of Tan II A and DDP treatment enhanced the p38 MAPK signaling pathway. Western blot assays showed higher p-p38, cleaved caspase-3, and Bax and lower caspase-3, and Bcl-2 expressions with the combination of Tan II A and DDP treatment compared to the single drug treatment (P<0.01). CONCLUSION Tan II A synergizes with DDP by activating the p38/MAPK pathway to upregulate cleaved caspase-3 and Bax pro-apoptotic gene expressions, and downregulate caspase-3 and Bcl-2 inhibitory apoptotic gene expressions, thereby enhancing the chemosensitivity of osteosarcoma cells to DDP.
Abietanes/therapeutic use* ; Osteosarcoma/enzymology* ; Cisplatin/therapeutic use* ; Humans ; Cell Line, Tumor ; Animals ; Apoptosis/drug effects* ; Mice, Nude ; Cell Proliferation/drug effects* ; Cell Movement/drug effects* ; p38 Mitogen-Activated Protein Kinases/metabolism* ; MAP Kinase Signaling System/drug effects* ; Bone Neoplasms/enzymology* ; Cell Cycle/drug effects* ; Xenograft Model Antitumor Assays ; Mice ; Drug Resistance, Neoplasm/drug effects* ; Neoplasm Invasiveness ; Mice, Inbred BALB C