Purpose Flavonols, a class of polyphenols, show a variety of biological activities such as antioxidant and anticancer. However, rapid in vivo O-glucuronidation posed a challenge to develop them as therapeutic agents. The objective of this paper is to determine the regioselective glucuronidation of flavonols by UGT1A isoforms (i.e., UGT1A1, UGT1A3, UGT1A7, UGT1A8, UGT1A9 and UGT1A10). Methods The kinetics of UGT1A1-, 1A3- and 1A7~1A10-mediated metabolisms of four flavonols that contain 7-OH group were characterized and kinetic parameters (Km, Vmax and intrinsic clearance (CLint=Vmax/Km)) were determined. Results UGT1A1 and 1A3 regioselectively metabolized 7-OH, whereas UGT1A7~1A10 preferred to glucuronidate 3-OH group. UGT1A1 and UGT1A9 were the most efficient conjugating enzymes with Km of ≤1 µM and Vmax/Km of >3 ml/min/mg protein, resulting in a CLint value as high as 6 ml/min/mg protein. Additionally, the four flavonols generally strongly self-inhibited the UGT1A1-mediated glucuronidation, with Ks (substrate inhibition constant) of ≤ 5.4 µM. Conclusion UGT1A isoforms displayed distinct positional preferences between 3-OH and 7-OH in the glucuronidation of flavonols. The differentiated kinetics properties between 3-O- and 7-O- glucuronidation indicated that at least two distinct binding modes within the catalytic domain were responsible for the formation of these two glucuronide isomers.

Insulin-like growth factor-II mRNA-binding protein 3 (IMP3) is a newly identified oncofetal mRNA-binding protein that is involved in embryogenesis and carcinogenesis of some malignant neoplasms. To investigate the diagnostic and clinicopathologic significance of this protein in endometrial carcinomas, we evaluated immunohistochemical expression of IMP3 in the two most common forms of endometrial malignancies, endometrioid adenocarcinoma and serous carcinoma. We selected 167 endometrial adenocarcinoma cases including 122 cases of endometrioid adenocarcinoma and 45 cases of serous carcinoma. Twenty samples of benign endometrium obtained from 20 patients with nonmalignant uterine lesions were used as controls. Positive immunohistochemical stain for IMP3 was identified in all serous carcinoma cases, among which, 39 (86%) and 3 (7%) cases showed IMP3 immunoreactivity in 450%, and 21-50, or 6-20% of tumor cells, respectively. Immunohistochemical reaction intensity for IMP3 was identified to be strong in 38 (84%) and intermediate in 7 (16%) cases of serous carcinoma. Fifty-four (44%) cases of endometrioid adenocarcinoma were negative for IMP3. Thirty (25%), 20 (16%), 10 (8%), and 8 (7%) cases of endometrioid adenocarcinoma demonstrated positive immunoreactivity for IMP3 in 1-5, 6-20, 21-50, and 450% of the tumor cells. Strong IMP3-staining intensity was noted in 34 (28%), intermediate in 26 (21%), and weak in 8 (7%) cases of endometrioid adenocarcinoma. All 20 control cases were negative for IMP3. To compare p53 with IMP3 expressions, we found that 35 (78%) of the serous carcinoma cases showed strong p53 immunohistochemical activity in 450% of the tumor cell nuclei. In contrast, 11 of 112 (10%) endometrioid adenocarcinoma cases demonstrated strong p53 positivity in 450% of the tumor cell nuclei. In conclusion, our findings demonstrate significant expression of IMP3 in serous carcinoma as compared to endometrioid adenocarcinoma (Po0.0001). Expression of IMP3 and p53 may be helpful biomarkers in the distinction of endometrial serous carcinoma from endometrioid adenocarcinoma. In addition, expression of IMP3 in endometrioid adenocarcinoma correlates with higher nuclear and architecture grades of the tumor (P ¼ 0.0000 and P ¼ 0.0002, respectively).

ABSTRACT:The interplay between phase II enzymes and efflux transporters leads to extensive metabolism and low bioavailability for flavonoids. To investigate the simplest interplay between one UDPglucuronosyltransferase isoform and one efflux transporter in flavonoid disposition, engineered HeLa cells stably overexpressing UGT1A9 were developed, characterized, and further applied to In conclusion, the engineered HeLa cells overexpressing UGT1A9 is an appropriate model to study the kinetic interplay between UGT1A9 and BCRP in the phase II disposition of flavonoids. This simple cell model should also be very useful to rapidly identify whether a phase II metabolite is the substrate of BCRP.

Galectin-4 is a multifunctional lectin found at both intracellular and extracellular sites. It could serve as a tumor suppressor intracellularly and promote tumor metastases extracellularly during colorectal cancer development. However, galectin-4 expression and its prognostic value for patients with hepatocellular carcinoma (HCC) have not been well investigated. Here we report that galectin-4 was significantly downregulated in early recurrent/metastatic HCC patients, when compared to non-recurrent/metastatic HCC patients. Low expression of gelectin-4 was well associated with larger tumor size, microvascular invasion, malignant differentiation, more advanced TNM stage, and poor prognosis. Cancer cell migration and invasion could be significantly reduced through overexpression of galectin-4, but upregulated by knocking down of galectin-4 in vitro. Moreover, the serum galectin-4 level could be significantly elevated solely by hepatitis B virus infection. Combined with clinicopathological features, the higher serologic level of galectin-4 was well associated with more aggressive characteristics of HCC. Taken together, galectin-4 expression closely associates with HCC progression and might have potential use as a prognostic biomarker for HCC patients.

BackgroundHepatic resection is the preferred treatment for huge hepatocellular carcinoma (>10 cm in diameter; H-HCC). However, the patients with H-HCC suffer from poor prognosis due to the early recurrence/metastasis. The underlying mechanism of H-HCC’s early recurrence/metastasis is currently not well understood.ResultsHere, we describe an Isobaric Tags for relative and absolute quantification (iTRAQ)-based quantitative proteomics approach to analyze the early recurrence/metastasis related proteins of H-HCC after radical resection through multidimensional chromatography coupled with tandem mass spectrometry (2DLC-MS/MS). The different protein expression profiles between the early recurrence/metastasis within 6 months(R/M≤6months) and late recurrence/metastasis within 6–12 months after surgery (R/M6-12months) were confirmed and might reveal different underlying molecular mechanisms. We identified 44 and 49 significantly differentially expressed proteins in the R/M≤6months group and the R/M6-12months group compared to the group who had no recurrence within 2 years post surgery (the NR/M group), respectively. Moreover, among those proteins, S100A12 and AMACR were down regulated in the R/M≤6months group but up-regulated in the R/M6-12months group; and this regulation was further confirmed in mRNA and protein level by Q-PCR, Western-Blot and Immunohistochemistry (IHC).ConclusionsThis current study presents the first proteomic profile of the early recurrence/metastasis of H-HCC. The results suggest that S100A12 and AMACR might be potential prognostic markers for predicting the early recurrence/metastasis of H-HCC after hepatectomy.