ABSTRACT
Although docetaxel (DTX) confers significant survival benefits in patients with castration-resistant prostate cancer (CRPC), resistance to DTX inevitably occurs. Therefore, clarifying the mechanisms of DTX resistance may improve survival in patients with CRPC. Claspin plays a pivotal role in DNA replication stress and damage responses and is an essential regulator for the S-phase checkpoint. CLSPN is an oncogenic gene that contributes to tumor proliferation in several human solid tumors. However, the clinical significance of claspin in prostate cancer (PCa) has not been examined. The present study aimed to elucidate the role of claspin and its relationship with DTX resistance in PCa. We immunohistochemically analyzed the expression of claspin in 89 PCa cases, of which 31 (35%) were positive for claspin. Claspin-positive cases were associated with higher Gleason score, venous invasion, and perineural invasion. Kaplan-Meier analysis showed that high claspin expression was related to poor prostate-specific antigen (PSA) relapse-free prognosis. In a public database, high CLSPN expression was associated with poor PSA relapse-free prognosis, Gleason score, T stage, lymph node metastasis, CRPC, and metastatic PCa. Claspin knockdown by siRNA decreased cell proliferation, upregulated DTX sensitivity, and suppressed the expression of Akt, Erk1/2, and CHK1 phosphorylation in DU145 and PC3 cell lines. Furthermore, claspin expression was much more upregulated in DTX-resistant DU145 (DU145-DR) than in parental DU145 cells. Claspin knockdown significantly upregulated the sensitivity to DTX in DU145-DR cells. These results suggest that claspin plays an important role in PCa tumor progression and DTX resistance.
Subject(s)
Adaptor Proteins, Signal Transducing/genetics , Docetaxel/pharmacology , Drug Resistance, Neoplasm/genetics , Neoplasm Recurrence, Local/genetics , Prostatic Neoplasms/drug therapy , Aged , Datasets as Topic , Disease-Free Survival , Docetaxel/therapeutic use , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Gene Knockdown Techniques , Humans , Kallikreins/blood , Kaplan-Meier Estimate , Male , Neoplasm Grading , Neoplasm Recurrence, Local/blood , Neoplasm Recurrence, Local/diagnosis , Neoplasm Recurrence, Local/epidemiology , PC-3 Cells , Prostate-Specific Antigen/blood , Prostatic Neoplasms/blood , Prostatic Neoplasms/genetics , Prostatic Neoplasms/mortality , Retrospective Studies , Up-RegulationABSTRACT
Colorectal cancer (CRC) is the second leading cause of cancer-related mortality worldwide. Kinesin Family Member C1 (KIFC1) has been proposed as a promising therapeutic target due to its pivotal role in centrosome clustering to mediate cancer cell progression. This study aimed to analyze the expression and biological function of KIFC1 in CRC. Immunohistochemically, 67 (52%) of 129 CRC cases were positive for KIFC1 and statistically associated with poorer overall survival. KIFC1 small interfering RNA (siRNA)-transfected cells demonstrated lower cell proliferation as compared to the negative control cells. A specific KIFC1 inhibitor, kolavenic acid analog (KAA) drastically inhibited CRC cell proliferation. Microarray analysis revealed that KAA-treated CRC cells presented reduced ZW10 interacting kinetochore protein (ZWINT) expression as compared to control cells. Immunohistochemical analysis demonstrated that 61 (47%) of 129 CRC cases were positive for ZWINT and ZWINT expression was significantly correlated with KIFC1 expression. ZWINT-positive cases exhibited significantly worse overall survival. KIFC1 siRNA-transfected cells showed reduced ZWINT expression while ZWINT siRNA-transfected cells decreased cell proliferation. Both KIFC1 and ZWINT knockdown cells attenuated spheroid formation ability. This study provides new insights into KIFC1 regulating ZWINT in CRC progression and its potential as a therapeutic target.
Subject(s)
Colorectal Neoplasms , Intracellular Signaling Peptides and Proteins/metabolism , Kinesins , Nuclear Proteins/metabolism , Antineoplastic Agents/pharmacology , Biomarkers, Tumor/metabolism , Cell Line, Tumor , Cell Proliferation , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/metabolism , Diterpenes/pharmacology , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Humans , Immunohistochemistry , Kinesins/genetics , Kinesins/metabolism , RNA, Small Interfering , TransfectionABSTRACT
BACKGROUND: Although unresectable or recurrent gastric cancers (GC) are frequently treated with platinum-based chemotherapy, response to treatment remains unpredictable. Because Schlafen 11 (SLFN11) is recently identified as a critical determinant of platinum sensitivity, we investigated the potential clinical utility of SLFN11 in the treatment of GC. METHODS: We analysed the correlation between SLFN11 expression and overall survival in 169 GC patients by our established immunohistochemical approach. The impact of SLFN11 expression on the response to platinum and transition of SLFN11 expression upon long-term treatment with platinum were examined using GC cell lines and organoids. RESULTS: GC patients with high-SLFN11 expression exhibited significantly better survival than those with low-SLFN11 expression, and the significance increased when we selected patients treated with platinum-based chemotherapy. Knockout of SLFN11 and reactivation of SLFN11 in GC cells conferred resistance and sensitivity to platinum, respectively. In GC cells and organoids, long-term treatment with oxaliplatin suppressed SLFN11 expression while imparting drug resistance. The acquired resistance to oxaliplatin was reversed by reactivation of SLFN11 with epigenetic modifying drugs. CONCLUSIONS: This is the first report revealing definitive clinical implications of SLFN11 in the treatment of GC patients and providing novel strategies for the drug selection based on SLFN11 expression.
