Pharmacogenetics of irinotecan, doxorubicin and docetaxel transporters in Asian and Caucasian cancer patients: a comparative review.

Drug efflux and influx transporters play critical roles in regulating the cellular drug disposition and modulating the pharmacokinetics and pharmacodynamics of anti-cancer agents, which may potentially alter treatment outcomes. The efficiency of drug transport is often dependent on the expression and activity of these membrane-bound proteins, factors which have been shown to be regulated by genes that are known to be highly polymorphic in different ethnic populations. The role of drug transporters becomes even more critical for anti-cancer agents due to the narrow therapeutic windows that separate treatment response and toxicities for these agents. Moreover, high inter-individual variability in the disposition of anti-cancer agents often results in variable treatment outcomes among patients receiving standard doses of the same drug. Such variability has been attributed at least in part to polymorphisms in genes encoding drug-metabolizing enzymes and transporter. To date, numerous pharmacogenetic studies have investigated the associations between variants in the ABC and SLC transporters genes with drug disposition, treatment outcomes and drug-induced toxicities. However, the strengths of these associations and their clinical relevance in different ethnic populations have not been critically examined. This review aims to summarize and evaluate the implications of pharmacogenetic variants in the ABC and SLC transporters genes on the pharmacokinetics and clinical outcomes of three anti-cancer agents: irinotecan, docetaxel and doxorubicin in Caucasian and Asian patients.

Y-box binding protein 1 is correlated with lymph node metastasis in intestinal-type gastric cancer.

AIMS: Y-box binding protein-1 (YB-1) is known to modulate gene transcription and protein translation, as well as cellular response to drug treatment. The aim of this study is to correlate YB-1 protein expression levels with clinicopathological parameters in intestinal-type gastric cancer tissue samples (as categorized by the Lauren classification) and substantiate the findings with in vitro experimentation. METHODS AND RESULTS: Paraffin-embedded samples from 167 patients with intestinal-type gastric cancer were used for the construction of tissue microarrays (TMAs). TMA slides were immunostained and YB-1 immunoreactivity score was based on the weighted average intensity score. Univariate analysis revealed that YB-1 immunohistochemical expression was correlated significantly with lymph node status (P = 0.054, borderline significance) and perforation (P = 0.043). YB-1 expression was also found to be an independent predictor of lymph node spread by multivariate analysis. Furthermore, siRNA-mediated YB-1 gene knockdown in MKN7 gastric cancer cells (which is known to originate from an intestinal-type gastric cancer tissue) inhibited cell migration (P = 0.0002) and invasion in vitro (P = 0.0129) significantly. CONCLUSION: YB-1 expression is associated with lymph node spread in intestinal-type gastric cancer and is a potential prognostic biomarker in this subtype of gastric cancer.

Therapeutic targeting of ARID1A-deficient cancer cells with RITA (Reactivating p53 and inducing tumor apoptosis).

ARID1A, a component of the SWI/SNF chromatin-remodeling complex, is frequently mutated in various cancer types and has emerged as a potential therapeutic target. In this study, we observed that ARID1A-deficient colorectal cancer (CRC) cells showed synthetic lethal effects with a p53 activator, RITA (reactivating p53 and inducing tumor apoptosis). RITA, an inhibitor of the p53-MDM2 interaction, exhibits increased sensitivity in ARID1A-deficient cells compared to ARID1A wild-type cells. Mechanistically, the observed synthetic lethality is dependent on both p53 activation and DNA damage accumulation, which are regulated by the interplay between ARID1A and RITA. ARID1A loss exhibits an opposing effect on p53 targets, leading to decreased p21 expression and increased levels of proapoptotic genes, PUMA and NOXA, which is further potentiated by RITA treatment, ultimately inducing cell apoptosis. Meanwhile, ARID1A loss aggravates RITA-induced DNA damage accumulation by downregulating Chk2 phosphorylation. Taken together, ARID1A loss significantly heightens sensitivity to RITA in CRC, revealing a novel synthetic lethal interaction between ARID1A and RITA. These findings present a promising therapeutic approach for colorectal cancer characterized by ARID1A loss-of-function mutations.

Association of LINC-PINT polymorphisms with lumbar disc herniation risk among Chinese Han population: a case control study.

BACKGROUND: Lumbar disc herniation (LDH) is a complex spinal disease, with multiple genetic polymorphisms being related to its risk. Nevertheless, the role of LINC-PINT polymorphisms in LDH risk has remained unknown. Therefore, this study aimed to investigate the association between LINC-PINT polymorphisms and LDH risk. METHODS: DNA was extracted from 504 LDH patients and 500 healthy controls. Three single nucleotide polymorphisms (SNPs) in LINC-PINT were selected and genotyped using Agena MassARRAY. We used logistic regression analysis to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs) under multiple genetic models to evaluate the association between LINC-PINT polymorphisms and LDH risk. Haploview 4.2 and SNPStats software were used to evaluate the linkage strength of SNPs and the correlation between haplotypes and LDH risk. The impact of SNP-SNP interactions on LDH risk was analyzed using multi-factor dimensionality reduction (MDR). RESULTS: Results showed that rs157916 (G vs. A: OR = 1.23, FDR-p = 0.029) and rs7801029 (G vs. C: OR = 1.39, FDR-p = 0.006; GG vs. CC: OR = 2.34, FDR-p = 0.038; recessive: OR = 2.13, FDR-p = 0.045; additive: OR = 1.39, FDR-p = 0.030) were associated with an increased risk of LDH. Furthermore, LINC-PINT rs157916 and rs780129 were found to be significantly associated with LDH risk in males. The "GGG" haplotype was associated with increased LDH risk (OR = 1.41, FDR-p = 0.006). MDR analysis indicated that the interaction between rs7801029 and rs16873842 was associated with an increased risk of LDH (OR = 1.47, p = 0.004). Additionally, there were significant differences in C-reactive protein levels among different genotypes of rs157916 and rs780129 (p < 0.05). CONCLUSION: This study suggests that LINC-PINT gene polymorphisms (rs157916 and rs7801029) are considered risk factors for LDH in the Chinese Han population and provide a scientific basis for early screening, prevention, and diagnosis of LDH.

Protect effect of bicyclol on cisplatin-induced nephrotoxicity in mice.

This study investigated the protective effects of bicyclol against cisplatin-induced nephrotoxicity and the possible mechanisms in mice. Bicyclol (250 mg/kg, p.o., 5 days) showed significant protection as evidenced by the decrease of elevated serum creatine and blood urea nitrogen, and improvement of histopathological injury induced by cisplatin. The formation of kidney malondialdehyde with a concomitant reduction of reduced glutathione were also inhibited by bicyclol, while the activities of kidney superoxide dismutase, catalase and glutathione peroxidase were all increased, respectively. Bicyclol also inhibited the increase of kidney and serum nitric oxide induced by cisplatin. In addition, induction of induced nitric oxide synthase and nitrotyrosine were suppressed by bicyclol. Bicyclol suppressed cisplatin-induced extracelluar signal regulated kinases 1/2 and p38 mitogen-activated protein kinase activation in the kidney of mice. Results obtained demonstrate that bicyclol pre-administration can prevent the nephrotoxicity induced by cisplatin.

[Effect of bicyclol on gene expression profiles in mice with liver injury induced by concanavalin A].

The aim of this study was to investigate the effect of the novel antihepatitis drug bicyclol on the gene expression profiles in concanavalin A (Con A) intoxicated mice by using cDNA microarray analysis. Bicyclol (250 mg x kg(-1)) was given orally to mice three doses before Con A intravenous injection (26.5 mg x kg(-1)). Serum levels of aminotransferases were examined by biochemical methods. Liver mRNA was extracted and reversely transcribed to cDNA with the incorporation of labeled Cy3-dUTP and Cy5-dUTP, separately. The probes were hybridized to the cDNA microarray. The acquired image was scanned and analyzed by Cenepix Pro 3.0 software. Microarray analysis showed that 287 genes exhibited differential expression in bicyclol group, in which 121 genes were up-regulated and 166 genes were down-regulated comparing with that of untreated Con A intoxicated mice. The differential gene expression after bicyclol treatment was involved in the biotransformation, protein synthesis, degradation and circadian rhythm, proliferation and signal transduction. Bicyclol might regulate a series of genes expressions in Con A intoxicated mice.

Methotrexate chemotherapy triggers touch-evoked pain and increased CGRP-positive sensory fibres in the tibial periosteum of young rats.

Although bone pain caused by cancer chemotherapy is a well-recognized and significant problem, with approximately 1 in 10 childhood cancer patients being reported to experience isolated bone pain along with other skeletal complications, the underlying mechanisms are poorly understood and there is no specific treatment. In this study, effects of methotrexate (MTX) treatment on pain in the hind legs and the extent of sensory innervation of the tibial bone were examined through a 20-day time course in young rats after 5 daily 0.75 mg/kg MTX injections. MTX treatment increased von-Frey filament stimulation-induced mechanical allodynia and palpation nocifensive score in the tibia. MTX-treated rats showed trends in reduced loading (numbers of stands) on hind limbs after palpation, commencing early during treatment and 2 weeks after the end of treatment despite no signs of ongoing pain during normal locomotion. Immunohistochemical analyses showed an increase in innervation of calcitonin gene-related peptide (CGRP)-positive sensory nerve fibres in tibial periosteum on days preceding and overlapping with those rats with touch-evoked pain responses and the bone repair phase. These data suggest that methotrexate chemotherapy triggers touch-evoked pain involving enhanced sensory nerve innervation of the bone.

Complement component 1, q subcomponent binding protein is a marker for proliferation in breast cancer.

Complement component 1, q subcomponent binding protein (C1QBP), is a multi-compartmental protein with higher mRNA expression reported in breast cancer tissues. This study evaluated the association between immunohistochemical expression of the C1QBP protein in breast cancer tissue microarrays (TMAs) and clinicopathological parameters, in particular tumor size. In addition, an in vitro study was conducted to substantiate the breast cancer TMA findings. Breast cancer TMAs were constructed from pathological specimens of patients diagnosed with invasive ductal carcinoma. C1QBP protein and proliferating cell nuclear antigen (PCNA) immunohistochemical analyses were subsequently performed in the TMAs. C1QBP immunostaining was detected in 131 out of 132 samples examined. The C1QBP protein was predominantly localized in the cytoplasm of the breast cancer cells. Univariate analysis revealed that a higher C1QBP protein expression was significantly associated with older patients (P = 0.001) and increased tumor size (P = 0.002). Multivariate analysis showed that C1QBP is an independent predictor of tumor size in progesterone-positive tumors. Furthermore, C1QBP was also significantly correlated with expression of PCNA, a known marker of proliferation. Inhibition of C1QBP expression was performed by transfecting C1QBP siRNA into T47D breast cancer cells, a progesterone receptor-positive breast cancer cell line. C1QBP gene expression was analyzed by real-time RT-PCR, and protein expression by Western blot. Cell proliferation assays were also performed by commercially available assays. Down-regulation of C1QBP expression significantly decreased cell proliferation and growth in T47D cells. Taken together, our findings suggest that the C1QBP protein could be a potential proliferative marker in breast cancer.

Surmounting chemoresistance by targeting the Y-box binding protein-1.

The Y-box binding protein 1 (YB-1), characterized by the presence of the cold shock domain, has been reported to induce chemoresistance in cancer therapy. Chemotherapy is one of the main therapeutic strategies in the treatment of cancer, in addition to surgery, radiation therapy, and hormonal therapy. However, chemoresistance remains a key obstacle to successful cancer management. In this review, we will focus on the role of YB-1, an important regulator of gene transcription, in cancer therapy and chemoresistance.

Breast cancer metastasis.

Breast cancer metastasis accounts for the majority of deaths from breast cancer. Detection of breast cancer metastasis at the earliest stage is important for the management and prediction of breast cancer progression. Emerging techniques using the analysis of circulating tumor cells show promising results in predicting and identifying the early stages of breast cancer metastasis in patients. Additionally, a deeper understanding of the metastatic cascade in breast cancer will be critical for developing therapeutic interventions to combat breast cancer metastasis. In this review, the current and novel methods for detection of breast cancer metastasis, as well as the mechanisms involved in metastasis and the treatment of breast cancer metastasis, are discussed.

TP53 genomic status regulates sensitivity of gastric cancer cells to the histone methylation inhibitor 3-deazaneplanocin A (DZNep).

PURPOSE: DZNep (3-deazaneplanocin A) depletes EZH2, a critical component of polycomb repressive complex 2 (PRC2), which is frequently deregulated in cancer. Despite exhibiting promising anticancer activity, the specific genetic determinants underlying DZNep responsiveness in cancer cells remain largely unknown. We sought to determine molecular factors influencing DZNep response in gastric cancer. EXPERIMENTAL DESIGN: Phenotypic effects of DZNep were evaluated in a panel of gastric cancer cell lines. Sensitive lines were molecularly interrogated to identify potential predictors of DZNep responsiveness. The functional importance of candidate predictors was evaluated using short hairpin RNA (shRNA) and siRNA technologies. RESULTS: DZNep depleted PRC2 pathway components in almost all gastric cancer lines, however, only a subset of lines exhibited growth inhibition upon treatment. TP53 genomic status was significantly associated with DZNep cellular responsiveness, with TP53 wild-type (WT) lines being more sensitive (P < 0.001). In TP53-WT lines, DZNep stabilized p53 by reducing ubiquitin conjugation through USP10 upregulation, resulting in activation of canonical p53 target genes. TP53 knockdown in TP53-WT lines attenuated DZNep sensitivity and p53 target activation, showing the functional importance of an intact p53 pathway in regulating DZNep cellular sensitivity. In primary human gastric cancers, EZH2 expression was negatively correlated with p53 pathway activation, suggesting that higher levels of EZH2 may repress p53 activity. CONCLUSION: Our results highlight an important role for TP53 genomic status in influencing DZNep response in gastric cancer. Clinical trials evaluating EZH2-targeting agents such as DZNep should consider stratifying patients with gastric cancer by their TP53 genomic status.

Silencing the Peroxiredoxin III gene inhibits cell proliferation in breast cancer.

Peroxiredoxin III (Prx III), an antioxidant protein found in mitochondria, plays an essential role in mitochondrial homeostasis. Aberrant expression of Prx III has been implicated in the tumorigenesis of various cancers. In this study, we evaluated the expression of Prx III in breast cancer tissues and elucidated its role in cell proliferation, a hallmark of cancer. Breast tissue microarrays comprising 106 breast cancer sections were stained with Prx III antibody using immunohistochemisty and correlated with proliferating cell nuclear antigen (PCNA) immunostaining. To validate the role of Prx III in cell proliferation, expression of Prx III was analyzed at the mRNA and protein levels by real-time RT-PCR, Western blotting and immunofluorescence in vitro. siRNA mediated silencing of Prx III in MDA-MB-231 breast cancer cells was performed and the effect on the cell cycle was examined. Prx III expression in patient tissue microarray samples was found to be positively associated with PCNA immunostaining, a proliferative marker. Prx III was expressed in both MCF-7 and MDA-MB-231 breast cancer cell lines and transient transfection with siPrx III in MDA-MB-231 cells induced inhibition of cell proliferation and cell cycle arrest. The data suggests that Prx III has a significant role in cell cycle regulation and could be a potential proliferation marker in breast cancer.

Y-box binding protein 1 is up-regulated in proliferative breast cancer and its inhibition deregulates the cell cycle.

The Y-box-binding protein 1 (YB-1), a member of the cold-shock domain RNA-and DNA-binding protein family, has pleiotropic functions such as regulation of the cell cycle. The aim of this study was to evaluate if YB-1 is a proliferative marker in breast cancer and elucidate potential downstream targets involved in YB-1-mediated cell cycle regulation using RNA interference technology. YB-1 protein expression was evaluated in tissue microarrays of 131 breast invasive ductal carcinomas by immunohistochemistry, while the YB-1 gene expression profile was evaluated in the T-47D, MDA-MB-231, ZR-75-1 and MCF7 breast cancer cell lines. Silencing of the YB-1 gene in T-47D breast cancer cells was performed using siRNA and the effects of down-regulation of YB-1 on cell growth and regulation of the cell cycle were ascertained. A focused panel of 84 genes involved in cell cycle progression was also examined. In tissue microarrays, YB-1 expression was shown to be associated with proliferating cell nuclear antigen (PCNA) immunostaining. siRNA-mediated silencing of the YB-1 gene inhibited cell proliferation and induced G1 phase cell cycle arrest in T-47D breast cancer cells. Knockdown of the YB-1 gene induced up-regulation of two genes which contribute to G1-arrest (RAD9A and CDKN3 genes) and down-regulation of ten genes associated with positive regulation of the cell cycle (SKP2, SUMO1, ANAPC4, CCNB1, CKS2, MNAT1, CDC20, RBBP8, KPNA2 and CCNC genes). The data obtained from the tissue microarrays and cell lines provide evidence that YB-1 is a reliable marker of cell proliferation and possibly a potential molecular target in breast cancer therapy.

Effect of bicyclol on cisplatin-induced hepatotoxicity in the hepatocarcinoma 22 tumour-bearing mice.

The aim of this study was to determine the effect of bicyclol against cisplatin-induced hepatotoxicity and the influence on the antitumour capacity of cisplatin in hepatocarcinoma 22 (H22) tumour-bearing mice. ICR mice were treated with bicyclol (250 mg/kg, orally) 2 hr before the injection of cisplatin (5 mg/kg, intraperitoneally) for 5 days (once daily) after H22 tumour cells were implanted. All animals were killed on the fifth day after cisplatin treatment and tumour weight of each animal was measured. Liver pathological changes were examined by light microscopy and biochemical assay. The expressions of liver inducible nitric oxide synthase (iNOS and nitric oxide synthase 2) and 3-nitrotyrosine were assessed by Western blotting. Bicyclol showed a significant protection as evidenced by the decrease of elevated serum aminotransferases and lactate dehydrogenase, and improvement of histopathological injury induced by cisplatin. The formation of liver malondialdehyde with a concomitant reduction of reduced glutathione was also inhibited by bicyclol, while the activities of liver superoxide dismutase, catalase and glutathione peroxidase were all increased, respectively. In addition, the over expressions of liver iNOS and 3-nitrotyrosine were suppressed by bicyclol. The administration of bicyclol had no affect on the anti-tumour capacity of cisplatin in mice bearing H22 tumour. The hepatoprotective action of bicyclol provides a new approach for preventing the hepatotoxicity induced by cisplatin in the clinic.