Kun-Huei Yeh

p27Kip1 ubiquitination and degradation is regulated by the SCFSkp2 complex through phosphorylated Thr187 in p27

Many tumorigenic processes affect cell-cycle progression by their effects on the levels of the cyclin-dependent kinase inhibitor p27(Kip1) [1,2]. The phosphorylation- and ubiquitination-dependent proteolysis of p27 is implicated in control of the G1-S transition in the cell cycle [3-6]. To determine the factors that control p27 stability, we established a cell-free extract assay that recapitulates the degradation of p27. Phosphorylation of p27 at Thr187 was essential for its degradation. Degradation was also dependent on SCF(Skp2), a protein complex implicated in targeting phosphorylated proteins for ubiquitination [7-10]. Immunodepletion of components of the complex - Cul-1, Skp1, or Skp2 - from the extract abolished p27 degradation, while addition of purified SCF(Skp2) to Skp2- depleted extract restored the capacity to degrade p27. A specific association was observed between Skp2 and a p27 carboxy-terminal peptide containing phosphorylated Thr187, but not between Skp2 and the non-phosphorylated peptide. Skp2-dependent associations between Skp1 or Cul-1 and the p27 phosphopeptide were also detected. Isolated SCF(Skp2) contained an E3 ubiquitin ligase activity towards p27. Our data thus suggest that SCF(Skp2) specifically targets p27 for degradation during cell-cycle progression.

Everolimus for Previously Treated Advanced Gastric Cancer: Results of the Randomized, Double-Blind, Phase III GRANITE-1 Study

PURPOSE The oral mammalian target of rapamycin inhibitor everolimus demonstrated promising efficacy in a phase II study of pretreated advanced gastric cancer. This international, double-blind, phase III study compared everolimus efficacy and safety with that of best supportive care (BSC) in previously treated advanced gastric cancer. PATIENTS AND METHODS Patients with advanced gastric cancer that progressed after one or two lines of systemic chemotherapy were randomly assigned to everolimus 10 mg/d (assignment schedule: 2:1) or matching placebo, both given with BSC. Randomization was stratified by previous chemotherapy lines (one v two) and region (Asia v rest of the world [ROW]). Treatment continued until disease progression or intolerable toxicity. Primary end point was overall survival (OS). Secondary end points included progression-free survival (PFS), overall response rate, and safety. RESULTS Six hundred fifty-six patients (median age, 62.0 years; 73.6% male) were enrolled. Median OS was 5.4 months with everolimus and 4.3 months with placebo (hazard ratio, 0.90; 95% CI, 0.75 to 1.08; P = .124). Median PFS was 1.7 months and 1.4 months in the everolimus and placebo arms, respectively (hazard ratio, 0.66; 95% CI, 0.56 to 0.78). Common grade 3/4 adverse events included anemia, decreased appetite, and fatigue. The safety profile was similar in patients enrolled in Asia versus ROW. CONCLUSION Compared with BSC, everolimus did not significantly improve overall survival for advanced gastric cancer that progressed after one or two lines of previous systemic chemotherapy. The safety profile observed for everolimus was consistent with that observed for everolimus in other cancers.

Lapatinib Plus Paclitaxel Versus Paclitaxel Alone in the Second-Line Treatment of HER2-Amplified Advanced Gastric Cancer in Asian Populations: TyTAN— A Randomized, Phase III Study

PURPOSE In Asian countries, paclitaxel once per week is used as second-line treatment in advanced gastric cancer, including human epidermal growth factor receptor 2 (HER2) -positive tumors. The role of anti-HER2 agents, including lapatinib, in this setting and population is unclear. PATIENTS AND METHODS TyTAN was a two-part, parallel-group, phase III study in Asian patients. An open-label, dose-optimization phase (n = 12) was followed by a randomized phase (n = 261), in which patients who were HER2 positive by fluorescence in situ hybridization (FISH) received lapatinib 1,500 mg once per day plus once-per-week paclitaxel 80 mg/m(2) or paclitaxel alone. The primary end point was overall survival (OS). Secondary end points included progression-free survival (PFS), time to progression (TTP), overall response rate (ORR), time to response, response duration, and safety. Analyses were based on immunohistochemistry (IHC) and gastrectomy status, prior trastuzumab therapy, and regional subpopulations. RESULTS Median OS was 11.0 months with lapatinib plus paclitaxel versus 8.9 months with paclitaxel alone (P = .1044), with no significant difference in median PFS (5.4 v 4.4 months) or TTP (5.5 v 4.4 months). ORR was higher with lapatinib plus paclitaxel versus paclitaxel alone (odds ratio, 3.85; P < .001). Better efficacy with lapatinib plus paclitaxel was demonstrated in IHC3+ compared with IHC0/1+ and 2+ patients and in Chinese compared with Japanese patients. A similar proportion of patients experienced adverse events with each treatment (lapatinib plus paclitaxel, 100% v paclitaxel alone, 98%). CONCLUSION Lapatinib plus paclitaxel demonstrated activity in the second-line treatment of patients with HER2 FISH-positive IHC3+ advanced gastric cancer but did not significantly improve OS in the intent-to-treat population.

Management of gastric cancer in Asia: resource-stratified guidelines

Gastric cancer is the fourth most common cancer globally, and is the second most common cause of death from cancer worldwide. About three-quarters of newly diagnosed cases in 2008 were from Asian countries. With a high mortality-to-incidence ratio, management of gastric cancer is challenging. We discuss evidence for optimum management of gastric cancer in aspects of screening and early detection, diagnosis, and staging; endoscopic and surgical intervention; and the concepts of perioperative, postoperative, and palliative chemotherapy and use of molecularly targeted therapy. Recommendations are formulated on the basis of the framework provided by the Breast Health Global Initiative, using the categories of basic, limited, enhanced, and maximum level. We aim to provide a stepwise strategy for management of gastric cancer applicable to different levels of health-care resources in Asian countries.

Regorafenib plus best supportive care versus placebo plus best supportive care in Asian patients with previously treated metastatic colorectal cancer (CONCUR): a randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND In the international randomised phase 3 CORRECT trial (NCT01103323), regorafenib significantly improved overall survival versus placebo in patients with treatment-refractory metastatic colorectal cancer. Of the 760 patients in CORRECT, 111 were Asian (mostly Japanese). This phase 3 trial was done to assess regorafenib in a broader population of Asian patients with refractory metastatic colorectal cancer than was studied in CORRECT. METHODS In this randomised, double-blind, placebo-controlled, parallel-group, phase 3 trial done in 25 hospitals in mainland China, Hong Kong, South Korea, Taiwan, and Vietnam, we recruited Asian patients aged 18 years or older with progressive metastatic colorectal cancer who had received at least two previous treatment lines or were unable to tolerate standard treatments. Patients had to have an Eastern Cooperative Oncology Group performance status of 0 or 1, life expectancy of at least 3 months, and adequate bone marrow, liver, and renal function, without other uncontrolled medical disorders. We randomly allocated patients (2:1; with a computer-generated unicentric randomisation list [prepared by the study funder] and interactive voice response system; block size of six; stratified by metastatic site [single vs multiple organs] and time from diagnosis of metastatic disease [<18 months vs ≥18 months]) to receive oral regorafenib 160 mg once daily or placebo on days 1-21 of each 28 day cycle; patients in both groups were also to receive best supportive care. Participants, investigators, and the study funder were masked to treatment assignment. The primary endpoint was overall survival, and we analysed data on an intention-to-treat basis. This trial is registered with ClinicalTrials.gov, number NCT01584830. FINDINGS Between April 29, 2012, and Feb 6, 2013, we screened 243 patients and randomly assigned 204 patients to receive either regorafenib (136 [67%]) or placebo (68 [33%]). After a median follow-up of 7·4 months (IQR 4·3-12·2), overall survival was significantly better with regorafenib than it was with placebo (hazard ratio 0·55, 95% CI 0·40-0·77, one-sided p=0·00016; median overall survival 8·8 months [95% CI 7·3-9·8] in the regorafenib group vs 6·3 months [4·8-7·6] in the placebo group). Drug-related adverse events occurred in 132 (97%) of 136 regorafenib recipients and 31 (46%) of 68 placebo recipients. The most frequent grade 3 or higher regorafenib-related adverse events were hand-foot skin reaction (22 [16%] of 136 patients in the regorafenib group vs none in the placebo group), hypertension (15 [11%] vs two [3%] of 68 patients in the placebo group), hyperbilirubinaemia (nine [7%] vs one [1%]), hypophosphataemia (nine [7%] vs none), alanine aminotransferase concentration increases (nine [7%] vs none), aspartate aminotransferase concentration increases (eight [6%] vs none), lipase concentration increases (six [4%] vs one [1%]), and maculopapular rash (six [4%] vs none). Drug-related serious adverse events occurred in 12 (9%) patients in the regorafenib group and three (4%) in the placebo group. INTERPRETATION This phase 3 trial is the second to show an overall survival benefit with regorafenib compared with placebo in patients with treatment-refractory metastatic colorectal cancer, substantiating the role of regorafenib as an important treatment option for patients whose disease has progressed after standard treatments. In this trial, preceding standard treatments did not necessarily include targeted treatments. Adverse events were generally consistent with the known safety profile of regorafenib in this setting. FUNDING Bayer HealthCare Pharmaceuticals.

High-frequency microsatellite instability predicts better chemosensitivity to high-dose 5-fluorouracil plus leucovorin chemotherapy for stage IV sporadic colorectal cancer after palliative bowel resection.

The influence of MSI on treatment outcome of colorectal cancers remains unclear and deserves further investigation. We recruited 244 patients with stage IV sporadic colorectal cancers for our study, based on appropriate eligibility criteria. Patients were nonrandomly allocated to 2 treatment groups of either with or without high‐dose 5‐FU plus leucovorin chemotherapy (HDFL, 5‐FU 2,600 mg/m2 leucovorin 300 mg/m2 maximum 500 mg). Each treatment group was further divided into 2 subgroups according to high‐frequency MSI (MSI‐H) status. MSI‐H was defined as the appearance of MSI in at least 2 of the 5 examined chromosomal loci (BAT‐25, BAT‐26, D5S346, D2S123, D17S250). We compared clinicopathologic parameters, p53 overexpression and overall survival between the groups. In addition, 4 subgroups were identified as follows: MSI‐H+HDFL+, n = 35; MSI‐H−HDFL+, n = 134; MSI‐H+HDFL−, n = 17; MSI‐H−HDFL−, n = 58. There was no significant difference of background clinicopathologic data between the HDFL+ and HDFL− treatment groups (p > 0.05). Survival analyses indicated that the patients of subgroup MSI‐H+HDFL+ survived significantly longer than those of subgroup MSI‐H−HDFL+, with median survival times of 24 (95% CI 20.2–27.9) and 13 (95% CI 11.6–14.4) months, respectively (p = 0.0001, log‐rank test). In contrast, in patients without chemotherapy, the prognosis was poor irrespective of MSI status, with median survival times of 7.0 (95% CI 4.6–9.4) and 7.0 (95% CI 6.1–7.9) months in the MSI‐H+HDFL− and MSI‐H−HDFL− subgroups, respectively (p = 0.8205, log‐rank test). MSI‐H cancers responded significantly better to HDFL (p = 0.001), with a mean response rate of 65.71% (95% CI 49.98–81.44%) in subgroup MSI‐H+HDFL+ compared to 35.07% (95% CI 26.99–43.15%) in subgroup MSI‐H−HDFL+. There appeared to be no preferential metastatic site where response to HDFL can be predicted based on the MSI status of the primary tumor. Toxicity to HDFL was similarly minimal between MSI‐H+ and MSI‐H− patients (p > 0.05). Multivariate analysis of all patients further indicated that MSI‐H and chemotherapy were independent favorable prognostic parameters (p < 0.05). Thus, the better prognosis of stage IV sporadic colorectal cancers with MSI‐H may be associated with better chemosensitivity, rather than lower aggressiveness in biologic behavior.

Down-regulation of Phospho-Akt Is a Major Molecular Determinant of Bortezomib-Induced Apoptosis in Hepatocellular Carcinoma Cells

Bortezomib, a proteasome inhibitor, has been clinically approved for the treatment of myeloma and lymphoma. Here, we report a differential effect of bortezomib on apoptosis in four hepatocellular carcinoma (HCC) cell lines and identify the major molecular event that determines sensitivity. Although bortezomib inhibited proteasome activity to a similar extent in all HCC cell lines, it showed differential effects on their viability: Huh-7 (IC(50) 196 nmol/L), Sk-Hep1 (IC(50) 180 nmol/L), Hep3B (IC(50) 112 nmol/L), and resistant PLC5 (IC(50) >1,000 nmol/L). Bortezomib caused cell cycle arrest at G(2)-M phase in all HCC cells tested whereas apoptotic induction was found only in sensitive cells but not in PLC5 cells. No significant bortezomib-induced NF-kappaB changes were noted in Huh-7 and PLC5. Bortezomib down-regulated phospho-Akt (P-Akt) in a dose- and time-dependent manner in all sensitive HCC cells whereas no alterations of P-Akt were found in PLC5. Down-regulation of Akt1 by small interference RNA overcame the apoptotic resistance to bortezomib in PLC5 cells, but a constitutively activated Akt1 protected Huh-7 cells from bortezomib-induced apoptosis. Furthermore, bortezomib showed suppression of tumor growth with down-regulation of P-Akt in Huh-7 tumors but not in PLC5 tumors. Down-regulation of P-Akt represents a major molecular event of bortezomib-induced apoptosis in HCC cell lines and may be a biomarker for predicting clinical response to HCC treatment. Targeting Akt signaling overcomes drug resistance to bortezomib in HCC cells, which provides a new approach for the combinational therapy of HCC.

Nivolumab in patients with advanced gastric or gastro-oesophageal junction cancer refractory to, or intolerant of, at least two previous chemotherapy regimens (ONO-4538-12, ATTRACTION-2): a randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND Patients with advanced gastric or gastro-oesophageal junction cancer refractory to, or intolerant of, two or more previous regimens of chemotherapy have a poor prognosis, and current guidelines do not recommend any specific treatments for these patients. We assessed the efficacy and safety of nivolumab, a fully human IgG4 monoclonal antibody inhibitor of programmed death-1 (PD-1), in patients with advanced gastric or gastro-oesophageal junction cancer who had been previously been treated with two or more chemotherapy regimens. METHODS In this randomised, double-blind, placebo-controlled, phase 3 trial done at 49 clinical sites in Japan, South Korea, and Taiwan, eligible patients (aged ≥20 years with unresectable advanced or recurrent gastric or gastro-oesophageal junction cancer refractory to, or intolerant of, standard therapy [including two or more previous chemotherapy regimens], with an Eastern Cooperative Oncology Group [ECOG] performance status of 0-1, and naive to anti-PD-1 therapy or other therapeutic antibodies and pharmacotherapies for the regulation of T cells) were recruited. Patients were randomly assigned (2:1) using an interactive web response system to receive 3 mg/kg nivolumab or placebo intravenously every 2 weeks, stratified by country, ECOG performance status, and number of organs with metastases. Study treatment was continued until progressive disease per investigator assessment or onset of toxicities requiring permanent discontinuation. Patients and investigators were masked to group assignment. The primary endpoint was overall survival in the intention-to-treat population. Safety was analysed in all patients who received at least one dose of study treatment. This study is ongoing but not recruiting new patients, and is registered with ClinicalTrials.gov, number NCT02267343. FINDINGS Between Nov 4, 2014, and Feb 26, 2016, we randomly assigned 493 patients to receive nivolumab (n=330) or placebo (n=163). At the data cutoff (Aug 13, 2016), median follow-up in surviving patients was 8·87 months (IQR 6·57-12·37) in the nivolumab group and 8·59 months (5·65-11·37) in the placebo group. Median overall survival was 5·26 months (95% CI 4·60-6·37) in the nivolumab group and 4·14 months (3·42-4·86) in the placebo group (hazard ratio 0·63, 95% CI 0·51-0·78; p<0·0001). 12-month overall survival rates were 26·2% (95% CI 20·7-32·0) with nivolumab and 10·9% (6·2-17·0) with placebo. Grade 3 or 4 treatment-related adverse events occurred in 34 (10%) of 330 patients who received nivolumab and seven (4%) of 161 patients who received placebo; treatment-related adverse events led to death in five (2%) of 330 patients in the nivolumab group and two (1%) of 161 patients in the placebo group. No new safety signals were observed. INTERPRETATION In this phase 3 study, the survival benefits indicate that nivolumab might be a new treatment option for heavily pretreated patients with advanced gastric or gastro-oesophageal junction cancer. Ongoing trials that include non-Asian patients are investigating nivolumab for advanced gastric or gastro-oesophageal junction cancer in various settings and earlier treatment lines. FUNDING Ono Pharmaceutical and Bristol-Myers Squibb.

High-dose 5-fluorouracil infusional therapy is associated with hyperammonaemia, lactic acidosis and encephalopathy

High-dose 5-fluorouracil infusional therapy is associated with hyperammonaemia, lactic acidosis and encephalopathy

Fibrosing Cholestatic Hepatitis in a Hepatitis B Surface Antigen Carrier After Renal Transplantation

A 45-year-old hepatitis B surface antigen carrier had an allograft kidney transplantation and maintenance immunosuppression with cyclosporin A and prednisolone. Six months later, she experienced a rapidly progressive hepatic failure manifested by elevation of serum bilirubin level, prolongation of prothrombin time, and mild to modest increase of serum aminotransferase levels. She died in 6 weeks. Postmortem liver histology showed canalicular and cellular cholestasis and ground-glass appearance and ballooning of most hepatocytes, but only mild inflammatory cell infiltration. Immunohistochemical staining showed massive loads of hepatitis B surface and core antigens in the hepatocytes and extensive periportal fibrosis. The whole picture was compatible with fibrosing cholestatic hepatitis described in hepatitis B virus-infected liver transplant. Sequencing of the hepatitis B virus genome amplified from the patients serum indicated a precore mutant but few mutations in the core, pre-S, and S genes. Little inflammatory reaction was observed histologically despite HLA compatibility, a situation differing from that in liver transplant. This observation indicates that fibrosing cholestatic hepatitis may also occur in non-liver transplant setting.