PTPLAD1 Regulates PHB-Raf Interaction to Orchestrate Epithelial-Mesenchymal and Mitofusion-Fission Transitions in Colorectal Cancer.

Colorectal cancer (CRC) remains one of the leading causes of cancer-related death worldwide. The poor prognosis of this malignancy is attributed mainly to the persistent activation of cancer signaling for metastasis. Here, we showed that protein tyrosine phosphatase-like A domain containing 1 (PTPLAD1) is down-regulated in highly metastatic CRC cells and negatively associated with poor survival of CRC patients. Systematic analysis reveals that epithelial-to-mesenchymal transition (EMT) and mitochondrial fusion-to-fission (MFT) transition are two critical features for CRC patients with low expression of PTPLAD1. PTPLAD1 overexpression suppresses the metastasis of CRC in vivo and in vitro by inhibiting the Raf/ERK signaling-mediated EMT and mitofission. Mechanically, PTPLAD1 binds with PHB via its middle fragment (141-178 amino acids) and induces dephosphorylation of PHB-Y259 to disrupt the interaction of PHB-Raf, resulting in the inactivation of Raf/ERK signaling. Our results unveil a novel mechanism in which Raf/ERK signaling activated in metastatic CRC induces EMT and mitochondrial fission simultaneously, which can be suppressed by PTPLAD1. This finding may provide a new paradigm for developing more effective treatment strategies for CRC.

Drug-Drug Interactions and Disease Status Are Associated With Irinotecan-Induced Hepatotoxicity: A Cross-Sectional Study in Shanghai.

Irinotecan-induced hepatotoxicity can cause severe clinical complications in patients; however, the underlying mechanism and factors affecting hepatotoxicity have rarely been investigated. In this cross-sectional study, we screened all clinical, demographic, medication, and genetic variables among 126 patients receiving irinotecan and explored potential associations with the incidence and time to onset of irinotecan-induced hepatotoxicity. Approximately 38.9% of the patients suffered from hepatotoxicity after irinotecan administration. The presence of cardiovascular diseases increases the incidence of hepatotoxicity ≈2.9-fold and doubles the hazard of time to hepatotoxicity. Patients with liver metastasis had a >4-fold higher risk of hepatotoxicity and a 3.5-fold increased hazard of time to hepatotoxicity compared to those without liver metastasis. Patients who took cytochrome P450 (CYP) 3A inducers had a 4.4-fold increased incidence of hepatotoxicity, and furthermore, concomitant use of platinum-based antineoplastics revealed 4.2 times the hazard of time to hepatotoxicity compared to those receiving antimetabolites. The cumulative dose of irinotecan (5-9 cycles) increased hepatotoxicity by 8.5 times. However, the genotypes and phenotypes of UGT1A1*28/*6 failed to be predictive factors of hepatotoxicity. The findings of this study suggest that irinotecan-induced hepatotoxicity is not directly associated with genetic variables but is mostly related to concomitant use of CYP3A4 inducers and platinum, as well as the presence of liver metastasis and cardiovascular disease. Thus, close monitoring of liver function is recommended, especially in patients with liver impairment or using CYP3A inducers and platinum antineoplastic drugs, which may be the best way to prevent hepatotoxicity.

Gene-Gene Interactions of Gemcitabine Metabolizing-Enzyme Genes hCNT3 and WEE1 for Preventing Severe Gemcitabine-Induced Hematological Toxicity.

Most patients experience severe hematological toxicity during treatment with gemcitabine; thus, preventing such toxicity would improve the treatment effects and patient quality of life. We analyzed 13 polymorphisms in the transporters, metabolizing enzymes, targets, and genes involved in DNA damage and the folate pathway among 132 patients treated with gemcitabine and studied their association with the severity of the hematological toxicities. Single-locus analysis showed that the single-nucleotide polymorphisms (SNPs) RRM1 rs12806698 and rs11031918 and DCTD rs7663494 were significantly associated with severe neutropenia, hENT1 rs760370 and hCNT3 rs7867504 and rs4877831 were associated with severe leukopenia, CDA rs2072671, DCTD rs7663494, and WEE1 rs3910384 were associated with severe anemia, and MTHFR rs1801133 was associated with severe thrombocytopenia after stringent Bonferroni correction (P < .0038). The gene-gene interaction analysis identified the overall best models, including a 2-way interaction model (hCNT3 rs7867504 and dCK rs12648166) for severe leukopenia (P = .0022) and a 3-locus model (CDA rs207671, DCTD rs7663494, and WEE1 rs3910384) for severe anemia with a strong synergistic effect (P = .0001). The association with hematological toxicity was further strengthened by the results of a haplotype analysis, in which the homozygous genotype combination of rs3910384 CC, rs2072671 AA, rs12648166 GG, rs7867504 CC, and rs7663494 TT conferred high genetic susceptibility to severe thrombocytopenia. Our results suggest that the gene-gene interaction of gemcitabine metabolic pathway genes and WEE1 contributes to susceptibility to gemcitabine-induced hematological toxicity. Moreover, we propose a promising data-mining analysis approach (generalized multifactor dimensionality reduction) to detect and characterize gene-gene interactions.

Anti-allergic drug azelastine suppresses colon tumorigenesis by directly targeting ARF1 to inhibit IQGAP1-ERK-Drp1-mediated mitochondrial fission.

This study aimed to screen novel anticancer strategies from FDA-approved non-cancer drugs and identify potential biomarkers and therapeutic targets for colorectal cancer (CRC). Methods: A library consisting of 1056 FDA-approved drugs was screened for anticancer agents. WST-1, colony-formation, flow cytometry, and tumor xenograft assays were used to determine the anticancer effect of azelastine. Quantitative proteomics, confocal imaging, Western blotting and JC-1 assays were performed to examine the effects on mitochondrial pathways. The target protein of azelastine was analyzed and confirmed by DARTS, WST-1, Biacore and tumor xenograft assays. Immunohistochemistry, gain- and loss-of-function experiments, WST-1, colony-formation, immunoprecipitation, and tumor xenograft assays were used to examine the functional and clinical significance of ARF1 in colon tumorigenesis. Results: Azelastine, a current anti-allergic drug, was found to exert a significant inhibitory effect on CRC cell proliferation in vitro and in vivo, but not on ARF1-deficient or ARF1-T48S mutant cells. ARF1 was identified as a direct target of azelastine. High ARF1 expression was associated with advanced stages and poor survival of CRC. ARF1 promoted colon tumorigenesis through its interaction with IQGAP1 and subsequent activation of ERK signaling and mitochondrial fission by enhancing the interaction of IQGAP1 with MEK and ERK. Mechanistically, azelastine bound to Thr-48 in ARF1 and repressed its activity, decreasing Drp1 phosphorylation. This, in turn, inhibited mitochondrial fission and suppressed colon tumorigenesis by blocking IQGAP1-ERK signaling. Conclusions: This study provides the first evidence that azelastine may be novel therapeutics for CRC treatment. ARF1 promotes colon tumorigenesis, representing a promising biomarker and therapeutic target in CRC.

Curcumol Overcomes TRAIL Resistance of Non-Small Cell Lung Cancer by Targeting NRH:Quinone Oxidoreductase 2 (NQO2).

Resistance to tumor-necrosis-factor-related apoptosis-inducing ligand (TRAIL) of cancer cell remains a key obstacle for clinical cancer therapies. To overcome TRAIL resistance, this study identifies curcumol as a novel safe sensitizer from a food-source compound library, which exhibits synergistic lethal effects in combination with TRAIL on non-small cell lung cancer (NSCLC). SILAC-based cellular thermal shift profiling identifies NRH:quinone oxidoreductase 2 (NQO2) as the key target of curcumol. Mechanistically, curcumol directly targets NQO2 to cause reactive oxygen species (ROS) generation, which triggers endoplasmic reticulum (ER) stress-C/EBP homologous protein (CHOP) death receptor (DR5) signaling, sensitizing NSCLC cell to TRAIL-induced apoptosis. Molecular docking analysis and surface plasmon resonance assay demonstrate that Phe178 in NQO2 is a critical site for curcumol binding. Mutation of Phe178 completely abolishes the function of NQO2 and augments the TRAIL sensitization. This study characterizes the functional role of NQO2 in TRAIL resistance and the sensitizing function of curcumol by directly targeting NQO2, highlighting the potential of using curcumol as an NQO2 inhibitor for clinical treatment of TRAIL-resistant cancers.

Identification of miR-515-3p and its targets, vimentin and MMP3, as a key regulatory mechanism in esophageal cancer metastasis: functional and clinical significance.

Metastasis is the main factor of treatment failure in cancer patients, but the underlying mechanism remains to be elucidated and effective new treatment strategies are urgently needed. This study aims to explore novel key metastasis-related microRNAs (miRNAs) in esophageal squamous cell carcinoma (ESCC). By comparing miRNA profiles of the highly metastatic ESCC cell sublines, we established through serial in vivo selection with the parental cells, we found that the expression level of miR-515-3p was lower in ESCC tumor tissues than adjacent normal tissues, further decreased in metastatic tumors, and moreover, markedly associated with advanced stage, metastasis and patient survival. The in vitro and in vivo assays suggested that miR-515-3p could increase the expression of the epithelial markers as well as decrease the expression of the mesenchymal markers, and more importantly, suppress invasion and metastasis of ESCC cells. Mechanistically, we revealed that miR-515-3p directly regulated vimentin and matrix metalloproteinase-3 (MMP3) expression by binding to the coding sequence and 3'untranslated region, respectively. In addition, the data from whole-genome methylation sequencing and methylation-specific PCR indicated that the CpG island within miR-515-3p promoter was markedly hypermethylated in ESCC cell lines and ESCC tumor tissues, which may lead to deregulation of miR-515-3p expression in ESCC. Furthermore, our preclinical experiment provides solid evidence that systemic delivery of miR-515-3p oligonucleotide obviously suppressed the metastasis of ESCC cells in nude mice. Taken together, this study demonstrates that miR-515-3p suppresses tumor metastasis and thus represents a promising prognostic biomarker and therapeutic strategy in ESCC.

Direct targeting of HSP90 with daurisoline destabilizes ß-catenin to suppress lung cancer tumorigenesis.

Lung cancer is the most frequent cancer worldwide with a poor prognosis. Identification of novel cancer targets and useful therapeutic strategies without toxicity are urgently needed. In this study, we screened natural products for anticancer bioactivity in a library consisting of 429 small molecules. We demonstrated for the first time that daurisoline, a constituent of Rhizoma Menispermi, repressed lung cancer cell proliferation by inducing cell cycle arrest at the G1 phase. Furthermore, daurisoline was found not only to suppress the growth of lung tumor xenografts in animals without obvious side effects, but also to inhibit cell migration and invasion. Mechanistically, quantitative proteomics and bioinformatics analyses, Western blotting and qRT-PCR confirmed that daurisoline exerted its anticancer effects by inhibiting the expression levels of ß-catenin and its downstream targets c-myc and cyclin D1. Furthermore, our data from Drug Affinity Responsive Target Stability (DARTS), isothermal titration calorimetry (ITC) and a series of functional assays demonstrated that daurisoline could target HSP90 directly and disrupt its interaction with ß-catenin, therefore increasing the ubiquitin-mediated proteasomal degradation of ß-catenin. This study reveals that daurisoline could be a promising therapeutic strategy for the treatment of lung cancer.

Comparative Proteomics Analysis Identifies Cdc42-Cdc42BPA Signaling as Prognostic Biomarker and Therapeutic Target for Colon Cancer Invasion.

Metastasis is one of the major causes of treatment failure in the patients with colon cancer. The aim of our study is to find key proteins and pathways that drive invasion and metastasis in colon cancer. Eight rounds of selection of cancer cells invading through matrigel-coated chamber were performed to obtain highly invasive colon cancer sublines HCT116-I8 and RKO-I8. Stable Isotope Labeling by Amino Acids in Cell Culture technology was used to identify the differently expressed proteins, and the proteomics data were analyzed by ingenuity pathway analysis. PAK1-PBD immunoprecipitation combined with Western blot were carried out to determine Cdc42 activity, and qRT-PCR and Western blot were used to determine gene expression. The functional role of Cdc42BPA and Cdc42 pathway in colon cancer invasion was studied by loss-of-function experiments including pharmacological blockade, siRNA knockdown, chamber invasion, and WST-1 assays. Human colon cancer tissue microarray was analyzed by immunohistochemistry for overexpression of Cdc42BPA and its correlation with clinicopathological parameters and patient survival outcomes. HCT116-I8 and RKO-I8 cells showed significantly stronger invasive potential as well as decreased E-cadherin and increased vimentin expressions compared with parental cells. The differently expressed proteins in I8 cells compared with parental cells were identified. Bioinformatics analysis of proteomics data suggested that Cdc42BPA protein and Cdc42 signaling pathway are important for colon cancer invasion, which was confirmed by experimental data showing upregulation of Cdc42BPA and higher expression of active GTP-bound form of Cdc42 in HCT116-I8 and RKO-I8 cells. Functionally, pharmacological and genetic blockade of Cdc42BPA and Cdc42 signaling markedly suppressed colon cancer cell invasion and reversed epithelial mesenchymal transition process. Furthermore, compared with adjacent normal tissues, Cdc42BPA expression was significantly higher in colon cancer tissues and further upregulated in metastatic tumors in lymph nodes. More importantly, Cdc42BPA expression was correlated with metastasis and poor survival of the patients with colon cancer. This study provides the first evidence that Cdc42BPA and Cdc42 signaling are important for colon cancer invasion, and Cdc42BPA has potential implications for colon cancer prognosis and treatment.

Inhibition of Nrf2 enhances the anticancer effect of 6-O-angeloylenolin in lung adenocarcinoma.

6-O-Angeloylenolin (6-OA), a sesquiterpene lactone isolated from Centipeda minima (L.) A. Br. (Compositae), has been used to treat respiratory diseases for centuries. However, whether and how 6-OA exerts anticancer effects against lung cancer remains to be elucidated. In this study, we showed that 6-OA markedly suppressed the cell viability and colony formation of lung cancer cells H1299 and A549, with no significant toxic effect on non-cancer cells HBE. Annexin V/7-AAD assay revealed that 6-OA induced cell apoptosis in dose- and time-dependent manners, which was further confirmed by the increased expression of cleaved caspase-3. To uncover the molecular mechanism how 6-OA exerts its anticancer effects, SILAC quantitative proteomics was performed to identify 6-OA-regulated proteins in lung cancer cells. Ingenuity Pathway Analysis revealed that these 6-OA-regulated proteins were mainly involved in Nrf2-mediated oxidative stress response, which was confirmed by the nuclear translocation of Nrf2 upon 6-OA treatment. Moreover, we found that 6-OA stimulated the accumulation of reactive oxygen species (ROS), whereas inhibition of ROS generation with N-acetyl l-cysteine could block the 6-OA-induced anticancer effects. Furthermore, blockade of cellular anti-oxidative system by Nrf2 knockdown significantly augmented the 6-OA-induced apoptosis. Taken together, we demonstrated that 6-OA exerts its anticancer effects by generating ROS, and inhibition of Nrf2 anti-oxidative system potentiated these effects. These results suggest that 6-OA may be used to treat lung cancer, with better outcome by combining with Nrf2 inhibitor to block Nrf2 pathway.

Organic anion transporting polypeptide-1B1 haplotypes in Chinese patients.

AIM: To detect 388G>A and 521T>C variant alleles in the organic anion transporting polypeptide-1B1 (OATP1B1, encoding gene SLCO1B1) gene. METHODS: One hundred and eleven healthy volunteers were screened for OATP1B1 alleles in our study. PCR-restriction fragment length polymorphism was used to identify the 388G>A polymorphism and a 1-step tetra-primer method was developed for the determination of 521T>C mutation. RESULTS: The frequencies of the 388G>A and 521T>C variant alleles in the Chinese population were 73.4% and 14.0%, respectively. The frequencies of the SLCO1B1*1b and *15 haplotypes were 59.9% and 14.0%, respectively. CONCLUSION: The SLCO1B1*1b and SLCO1B1*15 variants are relatively common in the Chinese population. Their frequencies are similar to that in the Japanese, but significantly different from that in Caucasians and blacks.

Effect of SLCO1B1 genetic polymorphism on the pharmacokinetics of nateglinide.

AIMS: Nateglinide is a meglitinide analogue with antidiabetic action. A recent study showed that SLCO1B1 (which codes the OATP1B1 gene, also known as OATP-C, OATP2) is a major determinant which markedly affects the pharmacokinetics of repaglinide. Our objective was to assess the association between single nucleotide polymorphisms (SNPs) of SLCO1B1 and the pharmacokinetics of nateglinide. METHODS: Seventeen healthy volunteers with different SLCO1B1 genotypes (11 with 521TT, four with 521TC and two with 521CC) were enrolled in this study. Each was given a single oral dose of 90 mg nateglinide. Plasma concentrations of nateglinide were measured up to 8 h by HPLC. RESULTS: The C(max) and AUC(0,infinity) of nateglinide were 83% (P = 0.002) and 82% (P = 0.001) higher in the SLCO1B1521TC subjects (n = 4), and 76% (P = 0.016) and 108% (P = 0.001) higher in the SLCO1B1521CC subjects (n = 2) than in the SLCO1B1521TT subjects (n = 11), respectively. The t(1/2) of nateglinide in SLCO1B1521CC subjects was 78% longer than that in 521TT subjects (P = 0.036). The difference in t(max) values among the three genotypic groups was not statistically significant. CONCLUSIONS: Our results suggest that OATP1B1-mediated hepatic uptake of nateglinide may be the prior step for its metabolism and elimination. SLCO1B1521T > C SNP might play an important role in the pharmacokinetics of nateglinide.

Arg257Cys polymorphism of CYP2A13 in a Chinese population.

BACKGROUND: Human cytochrome P450 2A13 (CYP2A13) is involved in the activation of numerous toxicants and carcinogens, especially in the metabolic activation of 4-(methyl-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a major tobacco-specific carcinogen. A functionally significant coding single nucleotide polymorphism (C3375T) in exon 5 of CYP2A13, which results in an amino acid substitution of Arg 257 to Cys, has been recently reported to exist in White, Black, Hispanic, and Asian individuals, with the variant 3375T allele frequencies being 1.9%, 14.4%, 5.8% and 7.7%, respectively. Since genetic background differs between ethnic groups, our present study aims to characterize the CYP2A13 Arg257Cys polymorphism in Chinese. METHODS: 258 healthy Chinese Han volunteers were involved in this study. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay was employed to genotype for the Arg257Cys polymorphism. RESULTS: Of all the 258 subjects, 27 (10.5%) heterozygotes and 1 (0.4%) homozygote for the 257Cys allele were detected. The frequency of the variant 257Cys allele in this Chinese population was 5.6% (95%CI: 4.2-7.0%). CONCLUSION: The CYP2A13 Arg257Cys variant represents a common polymorphism in Chinese, with the 257Cys allele frequency being similar to the Hispanic and Asian groups, but significantly lower than the Black.