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29 result(s) for "Poon, Ronnie Tung Ping"
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Phase 1 study of capmatinib in MET‐positive solid tumor patients: Dose escalation and expansion of selected cohorts
Capmatinib is an oral, ATP‐competitive, and highly potent, type 1b MET inhibitor. Herein, we report phase 1 dose‐escalation results for capmatinib in advanced MET‐positive solid tumor patients and dose expansion in advanced non‐lung tumors. Capmatinib was well tolerated with a manageable safety profile across all explored doses. Dose‐limiting toxicities (DLT) occurred at 200 mg twice daily (bid), 250 mg bid, and 450 mg bid capsules; however, no DLT were reported at 600 mg bid (capsules). Capmatinib tablets at 400 mg bid had comparable tolerability and exposure to that of 600 mg bid capsules. Maximum tolerated dose was not reached; recommended phase 2 dose was 400 mg bid tablets/600 mg bid capsules; at this dose, Ctrough >EC90 (90% inhibition of c‐MET phosphorylation in animal models) is expected to be achieved and maintained. Among the dose‐expansion patients (N = 38), best overall response across all cohorts was stable disease (gastric cancer 22%, hepatocellular carcinoma 46%, other indications 28%); two other indication patients with gene copy number (GCN) ≥6 achieved substantial tumor reduction. Near‐complete immunohistochemically determined phospho‐MET inhibition (H‐score = 2) was shown following capmatinib 450 mg bid capsule in paired biopsies obtained from one advanced colorectal cancer patient. Incidence of high‐level MET GCN (GCN ≥6) and MET‐overexpressing (immunohistochemistry 3+) tumors in the expansion cohorts was 8% and 13%, respectively; no MET mutations were observed. Thus, the recommended phase 2 dose (RP2D) of capmatinib was 600 mg bid capsule/400 mg bid tablet. Capmatinib was well tolerated and showed antitumor activity and acceptable safety profile at the RP2D. (ClinicalTrials.gov Identifier: NCT01324479). MET dysregulation is an important newly established molecular driver of tumorigenesis in various cancers and is recognized as a negative prognostic factor. The findings of this study provide the recommended phase 2 dose (RP2D) of capmatinib and also safety and efficacy data in selected expansion cohorts treated at the RP2D.
The Enhanced Metastatic Potential of Hepatocellular Carcinoma (HCC) Cells with Sorafenib Resistance
Acquired resistance towards sorafenib treatment was found in HCC patients, which results in poor prognosis. To investigate the enhanced metastatic potential of sorafenib resistance cells, sorafenib-resistant (SorR) cell lines were established by long-term exposure of the HCC cells to the maximum tolerated dose of sorafenib. Cell proliferation assay and qPCR of ABC transporter genes (ABCC1-3) were first performed to confirm the resistance of cells. Migration and invasion assays, and immunoblotting analysis on the expression of epithelial to mesenchymal transition (EMT) regulatory proteins were performed to study the metastatic potential of SorR cells. The expression of CD44 and CD133 were studied by flow cytometry and the gene expressions of pluripotency factors were studied by qPCR to demonstrate the enrichment of cancer stem cells (CSCs) in SorR cells. Control (CTL) and SorR cells were also injected orthotopically to the livers of NOD-SCID mice to investigate the development of lung metastasis. Increased expressions of ABCC1-3 were found in SorR cells. Enhanced migratory and invasive abilities of SorR cells were observed. The changes in expression of EMT regulatory proteins demonstrated an activation of the EMT process in SorR cells. Enriched proportion of CD44(+) and CD44(+)CD133(+) cells were also observed in SorR cells. All (8/8) mice injected with SorR cells demonstrated lung metastasis whereas only 1/8 mouse injected with CTL cells showed lung metastasis. HCC cells with sorafenib resistance demonstrated a higher metastatic potential, which may be due to the activated EMT process. Enriched CSCs were also demonstrated in the sorafenib resistant cells. This study suggests that advanced HCC patients with acquired sorafenib resistance may have enhanced tumor growth or distant metastasis, which raises the concern of long-term sorafenib treatment in advanced HCC patients who have developed resistance of sorafenib.
Biomarkers for predicting future metastasis of human gastrointestinal tumors
The recent advances in surgery and radiation therapy have significantly improved the prognosis of patients with primary cancer, and the major challenge of cancer treatment now is metastatic disease development. The 5-year survival rate of cancer patients who have distant metastasis at diagnosis is extremely low, suggesting that prediction and early detection of metastasis would definitely improve their prognosis because suitable patient therapeutic management and treatment strategy can be provided. Cancer cells from a primary site give rise to a metastatic tumor via a number of steps which require the involvement and altered expression of many regulators. These regulators may serve as biomarkers for predicting metastasis. Over the past few years, numerous regulators have been found correlating with metastasis. In this review, we summarize the findings of a number of potential biomarkers that are involved in cadherin–catenin interaction, integrin signaling, PI3K/Akt/mTOR signaling and cancer stem cell identification in gastrointestinal cancers. We will also discuss how certain biomarkers are associated with the tumor microenvironment that favors cancer metastasis.
Post-Operative Plasma Osteopontin Predicts Distant Metastasis in Human Colorectal Cancer
The overall prognosis of colorectal cancer (CRC) patients is unsatisfactory due to cancer metastasis after operation. This study aims to investigate the clinical significance of plasma osteopontin (OPN) levels as minimally invasive, predictive, and surrogate biomarkers for prognosis of CRC patients. This randomized study design consists of pre-operative and post-operative plasma samples from a total of 79 patients. We determined plasma levels of OPN by ELISA and examined their correlation with the clinicopathological parameters of CRC patients. The effects of endogenous and exogenous OPN on CRC metastasis were investigated by examination of the effect on regulators of epithelial to messenchymal transition and migration assay. Our findings demonstrated for the first time the clinical correlation of plasma OPN with metastasis of CRC patients. High post-operative plasma OPN level (>153.02 ng/ml) associated with development of metastasis after curative resection (p<0.001). Moreover, post-operative plasma OPN level correlated with disease-free survival of CRC patients (p=0.009) and was an independent factor for predicting development of metastasis in CRC patients after curative resection (p=0.036). Our in vitro model showed that OPN ectopic expression induced DLD1 cell migration through Snail and Twist1 overexpression and E-cadherin repression, and secretory OPN level enhanced cell migration. The results of the current study suggest that post-operative plasma OPN correlated with post-operative metastasis, suggesting that it is a potential non-invasive biomarker for the development of future metastasis in CRC patients. In addition, OPN was shown to be involved in the metastatic process and thus inhibition of OPN is a potential therapeutic approach to treat CRC patients.
Overexpression of Pin1 and rho signaling partners correlates with metastatic behavior and poor recurrence-free survival of hepatocellular carcinoma patients
Background Identification of molecular markers for early detection or prediction of metastasis is crucial for both management of HCC patient postoperative treatment and identify new therapeutic targets to inhibit HCC progression and metastasis. In the current study, we investigated the clinical correlation between Pin1, RhoA and RhoC and their association with HCC metastasis. Methods Using a randomized study design of primary HCC samples from 139 patients, we determined messenger RNA expression of Pin1, RhoA and RhoC and their prognostic value. Results Our findings demonstrated for the first time the clinical correlation of Pin1 in HCC metastasis. Pin1, RhoA and RhoC transcript levels were significantly higher in HCC specimens when compared with the paired adjacent non-tumorous liver. Pin1 overexpression was closely correlated with that of RhoA (R = 0.562, p  < 0.001) and RhoC (R = 0.529, p < 0.001), and their co-overexpressions correlated with metastatic HCC ( p  = 0.000012) and poor recurrence-free survival of HCC patients ( p  < 0.00001), which showed better prognostic significance than either Pin1, RhoA or RhoC overexpression alone. Co-overexpressions of Pin1 + RhoA/RhoC were also an independent factor for predicting development of metastasis after curative resection in our multivariate regression model ( p  < 0.001). Conclusion Pin1, RhoA and RhoC co-overexpressions are prognostic factor for metastatic HCC and predict poor recurrence-free survival.
Genome-Wide Association Study of Hepatocellular Carcinoma in Southern Chinese Patients with Chronic Hepatitis B Virus Infection
One of the most relevant risk factors for hepatocellular carcinoma (HCC) development is chronic hepatitis B virus (HBV) infection, but only a fraction of chronic HBV carriers develop HCC, indicating that complex interactions among viral, environmental and genetic factors lead to HCC in HBV-infected patients. So far, host genetic factors have incompletely been characterized. Therefore, we performed a genome-wide association (GWA) study in a Southern Chinese cohort consisting of 95 HBV-infected HCC patients (cases) and 97 HBV-infected patients without HCC (controls) using the Illumina Human610-Quad BeadChips. The top single nucleotide polymorphisms (SNPs) were then validated in an independent cohort of 500 cases and 728 controls. 4 SNPs (rs12682266, rs7821974, rs2275959, rs1573266) at chromosome 8p12 showed consistent association in both the GWA and replication phases (OR(combined) = 1.31-1.39; p(combined) = 2.71 × 10(-5)-5.19 × 10(-4); PAR(combined) = 26-31%). We found a 2.3-kb expressed sequence tag (EST) in the region using in-silico data mining and verified the existence of the full-length EST experimentally. The expression level of the EST was significantly reduced in human HCC tumors in comparison to the corresponding non-tumorous liver tissues (P<0.001). Results from sequence analysis and in-vitro protein translation study suggest that the transcript might function as a long non-coding RNA. In summary, our study suggests that variations at chromosome 8p12 may promote HCC in patients with HBV. Further functional studies of this region may help understand HBV-associated hepatocarcinogenesis.
Risk Factors and Post-Resection Independent Predictive Score for the Recurrence of Hepatitis B-Related Hepatocellular Carcinoma
Independent risk factors associated with hepatitis B (HBV)-related hepatocellular carcinoma (HCC) after resection remains unknown. An accurate risk score for HCC recurrence is lacking. We prospectively followed up 200 patients who underwent liver resection for HBV-related HCC for at least 2 years. Demographic, biochemical, tumor, virological and anti-viral treatment factors were analyzed to identify independent risk factors associated with recurrence after resection and a risk score for HCC recurrence formulated. Two hundred patients (80% male) who underwent liver resection for HBV-related HCC were recruited. The median time of recurrence was 184 weeks (IQR 52-207 weeks) for the entire cohort and 100 patients (50%) developed HCC recurrence. Stepwise Cox regression analysis identified that one-month post resection HBV DNA >20,000 IU/mL (p = 0.019; relative risk (RR) 1.67; 95% confidence interval (C.I.): 1.09-2.57), the presence of lymphovascular permeation (p<0.001; RR 2.69; 95% C.I.: 1.75-4.12), microsatellite lesions (p<0.001; RR 2.86; 95% C.I.: 1.82-4.51), and AFP >100ng/mL before resection (p = 0.021; RR 1.63; 95% C.I.: 1.08-2.47) were independently associated with HCC recurrence. Antiviral treatment before resection (p = 0.024; RR 0.1; 95% C.I.: 0.01-0.74) was independently associated with reduced risk of HCC recurrence. A post-resection independent predictive score (PRIPS) was derived and validated with sensitivity of 75.3% and 60.6% and specificity of 55.7% and 79.2%, to predict the 1- and 3-year risks for the HCC recurrence respectively with the hazard ratio of 2.71 (95% C.I.: 2.12-3.48; p<0.001). The AUC for the 1- and 3-year prediction were 0.675 (95% C.I.: 0.6-0.78) and 0.746 (95% C.I.: 0.69-0.82) respectively. Several tumor, virological and biochemical factors were associated with a higher cumulative risk of HCC recurrence after resection. PRIPS was derived for more accurate risk assessment. Regardless of the HBV DNA level, antiviral treatment should be given to patients before resection to reduce the risk of recurrence.
Osteopontin Overexpression Induced Tumor Progression and Chemoresistance to Oxaliplatin through Induction of Stem-Like Properties in Human Colorectal Cancer
Colorectal cancer (CRC) is one of the most common and fatal malignancies worldwide. The poor prognosis of colorectal cancer patients is due to development of chemoresistance and cancer metastasis. Recently osteopontin (OPN) has been associated with stem-like properties in colorectal cancer. This study further examined the clinicopathological significance of OPN in CRC and its effect on chemoresistance and transcription of stem cell markers. We examined the transcription level of OPN in 84 CRC patients and correlated the expression with their clinicopathological parameters. The associations of OPN overexpression with transcription of stem cell markers and response to chemotherapy in DLD1-OPN overexpressing clones and CRC patients were also investigated. Our results showed that OPN was significantly overexpressed in CRC, and its overexpression correlated with tumor stage and poor prognosis. Overexpression of CRC induced OCT4 and SOX2 expression in vitro and correlated with SOX2 overexpression in CRC patients. In addition, DLD1-OPN overexpressing cells showed enhanced ability to survive upon oxaliplatin treatment, and OPN expression was higher in CRC patients who were resistant to oxaliplatin-involved chemotherapy treatment. Thus, CRC cells overexpressing OPN demonstrated stem-like properties and OPN inhibition is a potential therapeutic approach to combat CRC progression and chemoresistance.
Microvascular Invasion Does Not Predict Long-Term Survival in Hepatocellular Carcinoma up to 2 cm: Reappraisal of the Staging System for Solitary Tumors
Background Excellent long-term outcomes have been reported recently for patients with small (≤2 cm) hepatocellular carcinoma (HCC). However, the significance of microvascular invasion (MVI) in small HCC remains unclear. The purpose of this study was to determine the impact of MVI in small HCC up to 2 cm. Methods In 1,109 patients with solitary HCC from six major international hepatobiliary centers, the impact of MVI on long-term survival in patients with small HCC (≤2 cm) and patients with tumors larger than 2 cm was analyzed. Results In patients with small HCC, long-term survival was not affected by MVI ( p  = 0.8), whereas in patients with larger HCC, significantly worse survival was observed in patients with MVI ( p  < 0.0001). In multivariate analysis, MVI (hazard ratio [HR] 1.59; 95 % confidence interval (CI) 1.27–1.99; p  < 0.001), elevated alpha-fetoprotein (HR 1.41; 95 % CI 1.11–1.8; p  = 0.005), and higher histologic grade (HR 1.29; 95 % CI 1.01–1.64; p  = 0.04) were significant predictors of worse survival in patients with HCC larger than 2 cm but were not correlated with long-term survival in small HCC. When the cohort was divided into three groups—HCC ≤2, >2 cm without MVI, and HCC >2 cm with MVI—significant between-group survival difference was observed ( p  < 0.0001). Conclusions Small HCC is associated with an excellent prognosis that is not affected by the presence of MVI. The discriminatory power of the 7th edition of the AJCC classification for solitary HCC could be further improved by subdividing tumors according to size (≤2 vs. >2 cm).
Over-Expression of miR-106b Promotes Cell Migration and Metastasis in Hepatocellular Carcinoma by Activating Epithelial-Mesenchymal Transition Process
Hepatocellular carcinoma (HCC) is one the the most fatal cancers worldwide. The poor prognosis of HCC is mainly due to the developement of distance metastasis. To investigate the mechanism of metastasis in HCC, an orthotopic HCC metastasis animal model was established. Two sets of primary liver tumor cell lines and corresponding lung metastasis cell lines were generated. In vitro functional analysis demonstrated that the metastatic cell line had higher invasion and migration ability when compared with the primary liver tumor cell line. These cell lines were subjected to microRNA (miRNAs) microarray analysis to identify differentially expressed miRNAs which were associated with the developement of metastasis in vivo. Fifteen human miRNAs, including miR-106b, were differentially expressed in 2 metastatic cell lines compared with the primary tumor cell lines. The clinical significance of miR-106b in 99 HCC clinical samples was studied. The results demonstrated that miR-106b was over-expressed in HCC tumor tissue compared with adjacent non-tumor tissue (p = 0.0005), and overexpression of miR-106b was signficantly correlated with higher tumor grade (p = 0.018). Further functional studies demonstrated that miR-106b could promote cell migration and stress fiber formation by over-expressing RhoGTPases, RhoA and RhoC. In vivo functional studies also showed that over-expression of miR-106b promoted HCC metastasis. These effects were related to the activation of the epithelial-mesenchymal transition (EMT) process. Our results suggested that miR-106b expression contributed to HCC metastasis by activating the EMT process promoting cell migration in vitro and metastasis in vivo.