A Pilot Study of Silymarin as Supplementation to Reduce Toxicities in Metastatic Colorectal Cancer Patients Treated With First-Line FOLFIRI Plus Bevacizumab.

Irinotecan, a topoisomerase inhibitor, is a common cytotoxic agent prescribed for metastatic colorectal cancer (mCRC) patients. Diarrhea is the most common adverse event (AE). The underlying mechanism of irinotecan-induced diarrhea is intestinal mucosal damage caused by SN-38 (active metabolite of irinotecan) hydrolyzed from SN-38G (inactive metabolite) by bacterial -glucuronidase (G). According to an animal study, silymarin reduces the activity of bacterial G without impairing antitumor efficacy. We conducted a prospective open-label pilot study to evaluate the effect of silymarin as supplementation in reducing toxicities of mCRC patients undergoing irinotecan-based chemotherapy. We enrolled and randomized 70 mCRC patients receiving first-line FOLFIRI (5-fluorouracil/leucovorin/irinotecan) plus bevacizumab. In each treatment cycle, the study group was administered silymarin capsules (150 mg) three times daily for 7 days. The study group experienced less AEs in diarrhea (5.7% vs. 14.6%, p=0.002) and nausea (27.0% vs. 40.2%, p=0.005) in comparison with the control group, but no significant differences in hepatic toxicities were observed. In conclusion, simultaneous administration of silymarin is a potential effective supplementation for reducing toxicities in mCRC patients undergoing first-line FOLFIRI plus bevacizumab, especially in diarrhea and nausea.

Chemical Constituent of ß-Glucuronidase Inhibitors from the Root of Neolitsea acuminatissima.

Neolitsea acuminatissima (Lauraceae) is an endemic plant in Taiwan. One new carboline alkaloid, demethoxydaibucarboline A (1), two new eudesmanolide-type sesquiterpenes, methyl-neolitacumone A (2), neolitacumone E (3), and twelve known compounds (4-15) were isolated from the root of Neolitsea acuminatissima. Their structures were elucidated by spectroscopic analysis. Glucuronidation represents a major metabolism process of detoxification for carcinogens in the liver. However, intestinal bacterial ß-Glucuronidase (ßG) has been considered pivotal to colorectal carcinogenesis. To develop specific bacterial-ßG inhibitors with no effect on human ßG, methanolic extract of roots of N. acuminatissima was selected to evaluate their anti-ßG activity. Among the isolates, demethoxydaibucarboline A (1) and quercetin (8) showed a strong bacterial ßG inhibitory effect with an inhibition ratio of about 80%. Methylneolitacumone A (2) and epicatechin (10) exhibited a moderate or weak inhibitory effect and the enzyme activity was less than 45% and 74%, respectively. These four compounds specifically inhibit bacterial ßG but not human ßG. Thus, they are expected to be used for the purpose of reducing chemotherapy-induced diarrhea (CID). The results suggest that the constituents of N. acuminatissima have the potential to be used as CID relief candidates. However, further investigation is required to determine their mechanisms of action.

Optimization of a multigene biochip for detection of relapsed and early relapsed colorectal cancer.

BACKGROUND: With the recent development of molecular markers, strategies for identifying patients with colorectal cancer (CRC) having a high risk of postoperative early relapse (within 1 y) and relapse have been improved. We previously constructed a multigene biochip with 19 candidate genes. The objective of the present study was to optimize a multigene biochip for detecting the risk of postoperative early relapse and relapse in patients with CRC. METHODS: We included 357 patients with stage I-III CRC who underwent curative resection at a single institution between June 2010 and May 2015. During each follow-up, a postoperative surveillance strategy including the National Comprehensive Cancer Network recommendations and a multigene biochip was used. A statistical algorithm was developed to select candidate biomarkers for an optimal combination. RESULTS: After a 30.9-mo median follow-up, 67 patients (18.8%) had postoperative relapse, of whom 25 (7.0%) relapsed within 1 y after operation and accounted for 37.3% of all relapsed patients. Of the 19 circulating biomarkers, ELAVL4, PTTG1, BIRC5, PDE6D, CHRNB1, MMP13, and PSG2, which presented significant predictive validity, were selected for combination. The expression of the seven-biomarker biochip resulted in area under the receiver operating characteristic curve values of 0.854 (95% confidence interval: 0.756-0.952) for early relapse and 0.884 (95% confidence interval: 0.830-0.939) for relapse. Moreover, the sensitivity, specificity, and predictive accuracy levels were 84.0%, 83.1%, and 83.2% for early relapse and 76.1%, 91.0%, and 88.2% for relapse (P = 0.415, 0.006, and 0.054, respectively). The median lead times before the detection of postoperative early relapse and relapse were 3.8 and 10.4 mo, respectively. CONCLUSIONS: From 19 circulating biomarkers, we optimized seven contemporary circulating biomarkers. The prediction model used for the early and accurate identification of Taiwanese patients with CRC having a high risk of postoperative early relapse and relapse seems to be feasible and comparable.

Discovery of specific inhibitors for intestinal E. coli ß-glucuronidase through in silico virtual screening.

Glucuronidation is a major metabolism process of detoxification for carcinogens, 4-(methylnitrosamino)-1-(3-pyridy)-1-butanone (NNK) and 1,2-dimethylhydrazine (DMH), of reactive oxygen species (ROS). However, intestinal E. coli ß-glucuronidase (eßG) has been considered pivotal to colorectal carcinogenesis. Specific inhibition of eßG may prevent reactivating the glucuronide-carcinogen and protect the intestine from ROS-mediated carcinogenesis. In order to develop specific eßG inhibitors, we found that 59 candidate compounds obtained from the initial virtual screening had high inhibition specificity against eßG but not human ßG. In particular, we found that compounds 7145 and 4041 with naphthalenylidene-benzenesulfonamide (NYBS) are highly effective and selective to inhibit eßG activity. Compound 4041 (IC50 = 2.8 µM) shows a higher inhibiting ability than compound 7145 (IC50 = 31.6 µM) against eßG. Furthermore, the molecular docking analysis indicates that compound 4041 has two hydrophobic contacts to residues L361 and I363 in the bacterial loop, but 7145 has one contact to L361. Only compound 4041 can bind to key residue (E413) at active site of eßG via hydrogen-bonding interactions. These novel NYBS-based eßG specific inhibitors may provide as novel candidate compounds, which specifically inhibit eßG to reduce eßG-based carcinogenesis and intestinal injury.

Gene expression profiles for predicting the efficacy of the anticancer drug 5-fluorouracil in breast cancer.

Chemotherapy is an important postsurgery adjuvant therapy in the treatment of breast cancer. However, because of the individual genotype differences of patients, the drug efficacy differs from person to person, even when the same chemotherapy drug is administered. The purpose of this research was to probe the gene expression profiles to predict the efficacy of 5-fluorouracil (5-FU), the common drug used in chemotherapy for various type of cancers, in Taiwanese breast cancer patients. Microarray analysis was conducted on the cancer cell line ZR-75-1 with and without 5-FU stimulation to identify the differentially expressed genes. The significant overexpressed gene groups were selected after bioinformatics software analysis to explore the molecular mechanism of 5-FU. Six strains of breast cancer cell line purchased from American Type Culture Collection were used to analyze the expression profiles of the above target gene groups. IL18, CCL28, CXCL2, SOD1, HRAS, FDXR, and CHI3L1 genes were significantly differentially expressed in 5-FU responder and nonresponder cell lines. The selected gene groups were validated with 20 strains of breast cancer primary cultures established previously in our laboratory. The experimental results demonstrated that FAM46A, IL18, CCL28, TNF, CXCL2, PLEKHA8, HRAS, FDXR, and CHI3L1 genes showed statistically significant differential expression between primary breast cancer culture cells that respond and nonrespond to 5-FU. Six genes, IL18, CCL28, CXCL2, HRAS, FDXR, and CHI3L1, showed significant differential expression pattern in both American Type Culture Collection and primary breast cancer cultured cells. The findings of this study may serve as basis for predicting the effectiveness of 5-FU on breast cancer.

ERCC2 2251A>C genetic polymorphism was highly correlated with early relapse in high-risk stage II and stage III colorectal cancer patients: a preliminary study.

BACKGROUND: Early relapse in colorectal cancer (CRC) patients is attributed mainly to the higher malignant entity (such as an unfavorable genotype, deeper tumor invasion, lymph node metastasis and advance cancer stage) and poor response to chemotherapy. Several investigations have demonstrated that genetic polymorphisms in drug-targeted genes, metabolizing enzymes, and DNA-repairing enzymes are all strongly correlated with inter-individual differences in the efficacy and toxicity of many treatment regimens. This preliminary study attempts to identify the correlation between genetic polymorphisms and clinicopathological features of CRC, and evaluates the relationship between genetic polymorphisms and chemotherapeutic susceptibility of Taiwanese CRC patients. To our knowledge, this study discusses, for the first time, early cancer relapse and its indication by multiple genes. METHODS: Six gene polymorphisms functional in drug-metabolism - GSTP1 Ile105Val, ABCB1 Ile1145Ile, MTHFR Ala222Val, TYMS double (2R) or triple (3R) tandem repeat - and DNA-repair genes - ERCC2 Lys751Gln and XRCC1 Arg399Gln - were assessed in 201 CRC patients using a polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) technique and DNA sequencing. Patients were diagnosed as either high-risk stage II (T2 and 3 N0 M0) or III (any T N1 and 2 M0) and were administered adjuvant chemotherapy regimens that included 5-fluorouracil (5FU) and leucovorin (LV). The correlations between genetic polymorphisms and patient clinicopathological features and relapses were investigated. RESULTS: In this study, the distributions of GSTP1 (P = 0.003), ABCB1 (P = 0.001), TYMS (P < 0.0001), ERCC2 (P < 0.0001) and XRCC1 (P = 0.006) genotypes in the Asian population, with the exception of MTHFR (P = 0.081), differed significantly from their distributions in a Caucasian population. However, the unfavorable genotype ERCC2 2251A>C (P = 0.006), tumor invasion depth (P = 0.025), lymph node metastasis (P = 0.011) and cancer stage (P = 0.008) were significantly correlated with early relapse. Patients carrying the ERCC2 2251AC or2251CC genotypes had a significantly increased risk of early relapse (OR = 3.294, 95% CI, 1.272-8.532). CONCLUSION: We suggest that ERCC2 2251A>C alleles may be genetic predictors of early CRC relapse.

Synthesis of Cysteine-Capped Zn(x)Cd(1)(-)(x)Se alloyed quantum dots emitting in the blue-green spectral range.

Alloyed ZnxCd1-xSe quantum dots (QDs) have been successfully prepared at low temperatures by reacting a mixture of Cd(ClO4)2 and Zn(ClO4)2 with NaHSe using cysteine as a surface-stabilizing agent. The photoluminescence (PL) spectra of the alloyed QDs are determined on the basis of the Zn2+/Cd2+ molar ratio, reaction pH, intrinsic Zn2+and Cd2+ reactivities toward NaHSe, concentration of NaHSe, and the kind of thiols. A systematic blue shift in emission wavelength of the alloyed QDs was found with the increase in the Zn mole fraction. This result provides clear evidence of the formation of ZnxCd1-xSe QDs by the simultaneous reaction of Zn2+ and Cd2+ with NaHSe, rather than the formation of separate CdSe and ZnSe nanocrystals or core-shell structure CdSe/ZnSe nanocrystals. The size and inner structure of these QDs are also corroborated by using high-resolution transmission electron microscopy and X-ray powder diffraction. To further understand the formation mechanism, the growth kinetics of Zn0.99Cd0.01Se was studied by measuring the PL spectra at different growth intervals. The results demonstrated that, in the initial stage of growth, Zn0.99Cd0.01Se has a structure with a Cd-rich core and a Zn-rich shell. The post-preparative irradiation of these QDs improved their PL properties, resulting in stronger emission.