Cancer multidrug resistance (MDR) impairs the therapeutic efficacy of various chemotherapeutics. Novel approaches, particularly the development of MDR reversal agents, are critically needed to address this challenge. This study demonstrates that tenacissoside I (TI), a compound isolated from Marsdenia tenacissima (Roxb.) Wight et Arn, traditionally used in clinical practice as an ethnic medicine for cancer treatment, exhibits significant MDR reversal effects in ABCB1-mediated MDR cancer cells. TI reversed the resistance of SW620/AD300 and KBV200 cells to doxorubicin (DOX) and paclitaxel (PAC) by downregulating ABCB1 expression and reducing ABCB1 drug transport function. Mechanistically, protein arginine methyltransferase 1 (PRMT1), whose expression correlates with poor prognosis and shows positive association with both ABCB1 and EGFR expressions in tumor tissues, was differentially expressed in TI-treated SW620/AD300 cells. SW620/AD300 and KBV200 cells exhibited elevated levels of EGFR asymmetric dimethylarginine (aDMA) and enhanced PRMT1-EGFR interaction compared to their parental cells. Moreover, TI-induced PRMT1 downregulation impaired PRMT1-mediated aDMA of EGFR, PRMT1-EGFR interaction, and EGFR downstream signaling in SW620/AD300 and KBV200 cells. These effects were significantly reversed by PRMT1 overexpression. Additionally, TI demonstrated resistance reversal to PAC in xenograft models without detectable toxicities. This study establishes TI's MDR reversal effect in ABCB1-mediated MDR human cancer cells through inhibition of PRMT1-mediated aDMA of EGFR, suggesting TI's potential as an MDR modulator for improving chemotherapy outcomes.
Humans ; Protein-Arginine N-Methyltransferases/antagonists & inhibitors* ; Drug Resistance, Neoplasm/drug effects* ; ErbB Receptors/genetics* ; Animals ; Cell Line, Tumor ; Drug Resistance, Multiple/drug effects* ; Methylation/drug effects* ; Saponins/administration & dosage* ; Mice ; Mice, Nude ; Mice, Inbred BALB C ; ATP Binding Cassette Transporter, Subfamily B/genetics* ; Doxorubicin/pharmacology* ; Paclitaxel/pharmacology* ; Female ; Repressor Proteins

With the rapid development of epidermal growth factor receptor (EGFR) gene testing of lung adenocarcinoma patients has been routinely carried out, EGFR mutations are also possible for some small samples of non-smoking female lung squamous cell carcinoma patients. This increases the opportunity for targeted therapy for this group of patients. However, drug resistance in patients with lung squamous cell carcinoma during targeted therapy is an important factor affecting subsequent treatment. There are multiple mechanisms of acquired drug resistance in targeted therapy, and the alteration of mesenchymal-epithelial transition factor (MET) signaling pathway is one of the common mechanisms of drug resistance. At present, some selective tyrosine kinase inhibitors (TKIs) of MET has been approved for non-small cell lung cancer with MET gene 14 exon skipping mutation, such as Glumetinib, Savolitinib, Tepotinib, Capmatinib, etc. Drugs that target secondary MET amplification are still in clinical trials. This paper retrospectively analyzed the clinical data of a female patient with EGFR-TKIs resistant secondary MET amplified squamous cell lung cancer, and reviewed relevant literature to explore how to optimize the treatment of lung squamous cell carcinoma patients with EGFR mutation, so as to provide clinical reference for the diagnosis and treatment of such patients.
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Female ; Humans ; Carcinoma, Squamous Cell/drug therapy* ; Drug Resistance, Neoplasm/genetics* ; ErbB Receptors/antagonists & inhibitors* ; Gene Amplification ; Lung Neoplasms/drug therapy* ; Protein Kinase Inhibitors/pharmacology* ; Proto-Oncogene Proteins c-met/genetics*

OBJECTIVE: To study the effects of the overexpression of autophagy-related gene 3 (ATG3) on autophagy and salinomycin-induced apoptosis in breast cancer cells and explore the underlying mechanisms. METHODS: We used the lentivirus approach to establish a breast cancer cell line with stable overexpression of ATG3. Western blotting, immunofluorescence staining and transmission electron microscopy were used to analyze the effect of ATG3 overexpression on autophagy in breast cancer MCF-7 cells. Using the AKT/mTOR agonists SC79 and MHY1485, we analyzed the effect of AKT/mTOR signal pathway activation on ATG3 overexpression-induced autophagy. Western blotting and flow cytometry were used to analyze the effect of autophagy on apoptosis of the ATG3-overexpressing cells treated with salinomycin and 3-MA (an autophagy inhibitor). RESULTS: In ATG3-overexpressing MCF-7 cells, ATG3 overexpression obviously promoted autophagy, inhibited the AKT/mTOR signaling pathway, significantly weakened salinomycin-induced apoptosis ( < 0.01), caused significant reduction of the levels of the pro-apoptotic proteins cleaved-caspase 3 ( < 0.01) and Bax ( < 0.05), and enhanced the expression of the anti-apoptotic protein Bcl-2 ( < 0.05). The inhibition of autophagy obviously weakened the inhibitory effect of ATG3 overexpression on salinomycin-induced apoptosis. CONCLUSIONS ATG3 overexpression promotes autophagy possibly by inhibiting the AKT/mTOR signaling pathway to decrease salinomycin-induced apoptosis in MCF-7 cells, suggesting that autophagy induction might be one of the mechanisms of drug resistance in breast cancer cells.
Acetates ; pharmacology ; Apoptosis ; drug effects ; genetics ; Autophagy ; drug effects ; Autophagy-Related Proteins ; metabolism ; Benzopyrans ; pharmacology ; Breast Neoplasms ; metabolism ; pathology ; Cell Line, Tumor ; Cell Proliferation ; Drug Resistance, Neoplasm ; Female ; Gene Expression Regulation ; Humans ; MCF-7 Cells ; Morpholines ; pharmacology ; Proto-Oncogene Proteins c-akt ; antagonists & inhibitors ; metabolism ; Pyrans ; pharmacology ; TOR Serine-Threonine Kinases ; antagonists & inhibitors ; metabolism ; Triazines ; pharmacology ; Ubiquitin-Conjugating Enzymes ; metabolism

OBJECTIVE: To investigate the interaction between interleukin-17 (IL-17) and interferon-γ (IFN-γ) and how their interaction affects the growth of mouse hepatoma Hepa1-6 cells. METHODS: Hepa1-6 cells treated with IL-17 and IFN-γ either alone or in combination were examined for changes in cell proliferation using MTT assay and in cell cycle distribution using flow cytometry. Western blotting was used to detect the protein expression levels of proliferating cell nuclear antigen (PCNA), cyclin D1, P21 and P16 and the phosphorylation of p38MAPK, ERK1/2 and Stat1 in the cells. RESULTS: Compared with control group, IFN-γ treatment obviously inhibited the growth and proliferation of Hepa1-6 cells, induced cell cycle arrest at G0/G1 phase, reduced the protein expression of PCNA and cyclin D1, and increased the protein expression of P21. IL-17 alone had no effect on the growth of Hepa1-6 cells. In the combined treatment, IL-17 significantly antagonized the effects of IFN-γ. Compared with those treated with IFN-γ alone, the cells with the combined treatment showed significantly decreased G0/G1 cell population, increased the protein expressions of PCNA and cyclin D1, and decreased the protein expression of P21. IL-17 significantly inhibited IFN-γ-induced phosphorylation of p38MAPK and ERK1/2 without affecting the phosphorylation of Stat1. CONCLUSIONS IL-17 obviously reverses the antitumor effects of IFN-γ to promote the proliferation of mouse hepatoma cells and accelerate the development of hepatocellular carcinoma.
Animals ; Carcinoma, Hepatocellular ; metabolism ; pathology ; Cell Cycle ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cyclin D1 ; metabolism ; Cyclin-Dependent Kinase Inhibitor p21 ; metabolism ; Interferon-gamma ; antagonists & inhibitors ; Interleukin-17 ; pharmacology ; Liver Neoplasms ; metabolism ; pathology ; Mice ; Neoplasm Proteins ; metabolism ; Proliferating Cell Nuclear Antigen ; metabolism

BACKGROUND: Long noncoding RNAs (lncRNAs) play pivotal roles in various malignant tumors. Epidermal growth factor receptor (EGFR) signaling is associated with the pathogenesis of cutaneous squamous cell carcinoma (cSCC). This study aimed to explore the role of LINC00520 in the development of cSCC via EGFR and phosphoinositide 3-kinase-protein kinase B (PI3K/Akt) signaling pathways. METHODS: A microarray analysis was applied to screen differentially expressed lncRNAs in cSCC samples. The A431 cSCC cell line was transfected and assigned different groups. The expression patterns of LINC00520, EGFR, and intermediates in the PI3K/Akt pathway were characterized using reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blotting analysis. Cell proliferation, migration, and invasion were detected using the MTT assay, scratch test, and Transwell assay, respectively. Cell-based experiments and a tumorigenicity assay were conducted to assess the effect of LINC00520 on cSCC progression. This study was ended in September 2017. Comparisons between two groups were analyzed with t-test and comparisons among multiple groups were analyzed using one-way analysis of variance. The nonparametric Wilcoxon rank sum test was used to analyze skewed data. The enumerated data were analyzed using the chi-square test or Fisher exact test. RESULTS: Data from chip GSE66359 revealed depletion of LINC00520 in cSCC. Cells transfected with LINC00520 vector and LINC00520 vector + si-EGFR showed elevated LINC00520 level but decreased levels of the EGFR, PI3K, AKT, VEGF, MMP-2 and MMP-9 mRNAs and proteins, and inhibition of the growth, migration and adhesion of cSCC cells, while the si-LINC00520 group showed opposite trends (all P < 0.05). Compared with the LINC00520 vector group, the LINC00520 vector + si-EGFR group showed decreased levels of the EGFR, PI3K, AKT, VEGF, MMP-2 and MMP-9 mRNAs and proteins, and inhibition of the growth, migration and adhesion of cSCC cells, while the LINC00520 vector + EGFR vector group showed opposite results (all P < 0.05). CONCLUSION Based on our results, LINC00520-targeted EGFR inhibition might result in the inactivation of the PI3K/Akt pathway, thus inhibiting cSCC development.
Animals ; Carcinoma, Squamous Cell ; pathology ; prevention & control ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Disease Progression ; ErbB Receptors ; antagonists & inhibitors ; Female ; Humans ; Lymphatic Metastasis ; Mice ; Neoplasm Invasiveness ; Phosphatidylinositol 3-Kinases ; physiology ; Proto-Oncogene Proteins c-akt ; physiology ; RNA, Long Noncoding ; physiology ; Signal Transduction ; physiology ; Skin Neoplasms ; pathology ; prevention & control

OBJECTIVE: To investigate the expression profile of miR-122-5p in melanoma tissues and the effect of miR-122-5p on the proliferation, cell cycle and apoptosis of human melanoma cell lines SK-MEL-110 and A375. METHODS: The expression profiles of miR-122-5p in melanoma and pigmented nevus tissues were detected using real-time fluorescence quantitative PCR (qRT-PCR). SK-MEL-110 and A375 cells transfected with miR-122-5p inhibitor or negative control inhibitor (NC) I were examined for miR-122- 5p expression using qRT-PCR and changes in cell proliferation, cell cycle and apoptosis using MTT assay or flow cytometry. NOP14 mRNA and protein expressions in the cells were detected using qRT- PCR and Western blotting, respectively. Luciferase reporter assay was used to confirm the identity of NOP14 as the direct target of miR-122-5p. RESULTS: The relative expression of miR-122-5p in human pigmented nevus tissues and melanoma tissues was 1.23±0.270 and 7.65 ± 1.37, respectively. The relative expression of miR-122-5p in SK-MEL-110 and A375 cells transfected with miR-122-5p inhibitor was 0.21 ± 0.08 and 0.17 ± 0.05, respectively. miR-122-5p inhibitor obviously inhibited the cell proliferation and increased the percentage of cells in G1 stage in both SK-MEL-110 and A-375 cells, but did not cause obvious changes in the apoptosis of the two cells. miR-122-5p inhibitor did not significantly affect the expression level of NOP14 mRNA, but obviously increased the expression level of NOP14 protein. Luciferase reporter assay revealed a significantly lower luciferase activity in cells co-transfected with miR-122-5p mimics and wild-type psi-CHECK2-3'UTR plasmid than in the cells cotransfected with NC and wild-type psi-CHECK2-3'UTR plasmid (0.21 ± 0.14 0.56 ± 0.1, < 0.01). CONCLUSIONS miR-122-5p expression is upregulated in melanoma tissues, indicating its involvement in the development of melanoma. miR-122-5p inhibits the proliferation of SK-MEL-110 and A-375 cells possibly by affecting the cycle through NOP14.
Apoptosis ; Cell Cycle ; Cell Line, Tumor ; Cell Proliferation ; Humans ; Luciferases ; metabolism ; Melanoma ; etiology ; metabolism ; pathology ; MicroRNAs ; antagonists & inhibitors ; metabolism ; Neoplasm Proteins ; metabolism ; Nevus, Pigmented ; etiology ; metabolism ; pathology ; Nuclear Proteins ; metabolism ; Skin Neoplasms ; etiology ; metabolism ; pathology ; Up-Regulation

Multidrug resistance (MDR) is one of the major obstacles in cancer chemotherapy. Our previous study has shown that icariin could reverse MDR in MG-63 doxorubicin-resistant (MG-63/DOX) cells. It is reported that icariin is usually metabolized to icariside II and icaritin. Herein, we investigated the effects of icariin, icariside II, and icaritin (ICT) on reversing MDR in MG-63/DOX cells. Among these compounds, ICT exhibited strongest effect and showed no obvious cytotoxicity effect on both MG-63 and MG-63/DOX cells ranging from 1 to 10 μmol·L. Furthermore, ICT increased accumulation of rhodamine 123 and 6-carboxyfluorescein diacetate and enhanced DOX-induced apoptosis in MG-63/DOX cells in a dose-dependent manner. Further studies demonstrated that ICT decreased the mRNA and protein levels of multidrug resistance protein 1 (MDR1) and multidrug resistance-associated protein 1 (MRP1). We also verified that blockade of STAT3 phosphorylation was involved in the reversal effect of multidrug resistance in MG-63/DOX cells. Taken together, these results indicated that ICT may be a potential candidate in chemotherapy for osteosarcoma.
ATP Binding Cassette Transporter, Subfamily B ; drug effects ; genetics ; metabolism ; Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Survival ; drug effects ; Dose-Response Relationship, Drug ; Doxorubicin ; metabolism ; pharmacology ; toxicity ; Drug Resistance, Multiple ; drug effects ; Drug Resistance, Neoplasm ; drug effects ; Flavonoids ; pharmacology ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Multidrug Resistance-Associated Proteins ; drug effects ; genetics ; metabolism ; Osteosarcoma ; drug therapy ; metabolism ; pathology ; Phosphorylation ; drug effects ; Rhodamine 123 ; metabolism ; STAT3 Transcription Factor ; antagonists & inhibitors ; metabolism ; Triterpenes ; pharmacology

The present study analyzed the predictive value of combined analysis of collapsin response mediator protein 4 (CRMP4) methylation levels and the Cancer of the Prostate Risk Assessment (CAPRA-S) Postsurgical score of patients who required adjuvant hormone therapy (AHT) after radical prostatectomy (RP). We retrospectively analyzed 305 patients with prostate cancer (PCa) who received RP and subsequent androgen deprivation therapy (ADT). Two hundred and thirty patients with clinically high-risk PCa underwent immediate ADT, and 75 patients with intermediate risk PCa underwent deferred ADT. CRMP4 methylation levels in biopsies were determined, and CAPRA-S scores were calculated. In the deferred ADT group, the values of the hazard ratios for tumor progression and cancer-specific mortality (CSM) in patients with ≥15% CRMP4 methylation were 6.81 (95% CI: 2.34-19.80) and 12.83 (95% CI: 2.16-26.10), respectively. Receiver-operating characteristic curve analysis indicated that CRMP4 methylation levels ≥15% served as a significant prognostic marker of tumor progression and CSM. In the immediate ADT group, CAPRA-S scores ≥6 and CRMP4 methylation levels ≥15% were independent predictors of these outcomes (uni- and multi-variable Cox regression analyses). The differences in the 5-year progression-free survival between each combination were statistically significant. Combining CAPRA-S score and CRMP4 methylation levels improved the area under the curve compared with the CRMP4 or CAPRA-S model. Therefore, CRMP4 methylation levels ≥15% were significantly associated with a poor prognosis and their combination with CAPRA-S score accurately predicted tumor progression and metastasis for patients requiring AHT after RP.
Aged ; Androgen Antagonists/therapeutic use* ; Biomarkers, Tumor/blood* ; Female ; Hormone Replacement Therapy ; Humans ; Male ; Methylation ; Middle Aged ; Muscle Proteins/metabolism* ; Neoplasm Grading ; Neoplasm Metastasis ; Neoplasm Staging ; Prognosis ; Progression-Free Survival ; Prostatectomy ; Prostatic Neoplasms/metabolism* ; Retrospective Studies ; Risk Assessment ; Treatment Outcome

PURPOSE: Rearrangement of the proto-oncogene rearranged during transfection (RET) has been newly identified potential driver mutation in lung adenocarcinoma. Clinically available tyrosine kinase inhibitors (TKIs) target RET kinase activity, which suggests that patients with RET fusion genes may be treatable with a kinase inhibitor. Nevertheless, the mechanisms of resistance to these agents remain largely unknown. Thus, the present study aimed to determine whether epidermal growth factor (EGF) and hepatocyte growth factor (HGF) trigger RET inhibitor resistance in LC-2/ad cells with CCDC6-RET fusion genes. MATERIALS AND METHODS: The effects of EGF and HGF on the susceptibility of a CCDC6-RET lung cancer cell line to RET inhibitors (sunitinib, E7080, vandetanib, and sorafenib) were examined. RESULTS: CCDC6-RET lung cancer cells were highly sensitive to RET inhibitors. EGF activated epidermal growth factor receptor (EGFR) and triggered resistance to sunitinib, E7080, vandetanib, and sorafenib by transducing bypass survival signaling through ERK and AKT. Reversible EGFR-TKI (gefitinib) resensitized cancer cells to RET inhibitors, even in the presence of EGF. Endothelial cells, which are known to produce EGF, decreased the sensitivity of CCDC6-RET lung cancer cells to RET inhibitors, an effect that was inhibited by EGFR small interfering RNA (siRNA), anti-EGFR antibody (cetuximab), and EGFR-TKI (Iressa). HGF had relatively little effect on the sensitivity to RET inhibitors. CONCLUSION: EGF could trigger resistance to RET inhibition in CCDC6-RET lung cancer cells, and endothelial cells may confer resistance to RET inhibitors by EGF. E7080 and other RET inhibitors may provide therapeutic benefits in the treatment of RET-positive lung cancer patients.
Adenocarcinoma/drug therapy/*genetics ; Cell Line, Tumor ; Cetuximab/pharmacology ; Drug Resistance, Neoplasm/drug effects/*genetics ; Epidermal Growth Factor/metabolism/*pharmacology ; *Gene Rearrangement ; Hepatocyte Growth Factor/*pharmacology ; Humans ; Indoles/pharmacology ; Lung Neoplasms/drug therapy/*genetics ; MAP Kinase Signaling System ; *Mutation ; Niacinamide/analogs & derivatives/pharmacology ; Phenylurea Compounds/pharmacology ; Piperidines/pharmacology ; Protein Kinase Inhibitors/therapeutic use ; Proto-Oncogene Proteins c-ret/*antagonists & inhibitors/genetics ; Pyrroles/pharmacology ; Quinazolines/pharmacology ; RNA, Small Interfering/pharmacology ; Receptor, Epidermal Growth Factor/genetics/metabolism ; Signal Transduction/drug effects ; fms-Like Tyrosine Kinase 3/metabolism

Antineoplastic Agents, Immunological ; immunology ; pharmacology ; Cell Line, Tumor ; GPI-Linked Proteins ; antagonists & inhibitors ; immunology ; Humans ; Neoplasm Proteins ; analysis ; immunology ; Pancreatic Neoplasms ; drug therapy ; immunology ; pathology