Sang Hee Cho

Large-scale genetic study in East Asians identifies six new loci associated with colorectal cancer risk

Known genetic loci explain only a small proportion of the familial relative risk of colorectal cancer (CRC). We conducted a genome-wide association study of CRC in East Asians with 14,963 cases and 31,945 controls and identified 6 new loci associated with CRC risk (P = 3.42 × 10−8 to 9.22 × 10−21) at 10q22.3, 10q25.2, 11q12.2, 12p13.31, 17p13.3 and 19q13.2. Two of these loci map to genes (TCF7L2 and TGFB1) with established roles in colorectal tumorigenesis. Four other loci are located in or near genes involved in transcriptional regulation (ZMIZ1), genome maintenance (FEN1), fatty acid metabolism (FADS1 and FADS2), cancer cell motility and metastasis (CD9), and cell growth and differentiation (NXN). We also found suggestive evidence for three additional loci associated with CRC risk near genome-wide significance at 8q24.11, 10q21.1 and 10q24.2. Furthermore, we replicated 22 previously reported CRC-associated loci. Our study provides insights into the genetic basis of CRC and suggests the involvement of new biological pathways.

S-1 plus oxaliplatin versus capecitabine plus oxaliplatin for first-line treatment of patients with metastatic colorectal cancer: a randomised, non-inferiority phase 3 trial

BACKGROUNDnCapecitabine plus oxaliplatin (CapeOX) is one of the reference doublet cytotoxic chemotherapy treatments for patients with metastatic colorectal cancer. We aimed to compare the efficacy and safety of CapeOX with that of S-1 plus oxaliplatin (SOX), a promising alternative treatment for patients with metastatic colorectal cancer.nnnMETHODSnIn this open-label, multicentre, randomised phase 3 trial, we randomly assigned patients (1:1) from 11 institutions in South Korea to receive either CapeOX (capecitabine 1000 mg/m(2) twice daily on days 1-14 and oxaliplatin 130 mg/m(2) on day 1) or SOX (S-1 40 mg/m(2) twice daily on days 1-14 and oxaliplatin 130 mg/m(2) on day 1). Treatment was repeated every 3 weeks and continued for as many as nine cycles of oxaliplatin-containing chemotherapy, except in instances of disease progression, unacceptable toxicity, or a patients refusal. Maintenance chemotherapy with S-1 or capecitabine was allowed after discontinuation of oxaliplatin. Randomisation was done with a computer-generated sequence (stratified by primary sites, previous adjuvant or neoadjuvant treatment, and the presence of measurable lesions). The primary endpoint was to show non-inferiority of SOX relative to CapeOX in terms of progression-free survival (PFS). The primary analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00677443.nnnFINDINGSnBetween May 14, 2008, and Sept 23, 2009, we randomly assigned 168 patients to receive SOX and 172 to receive CapeOX. Median PFS was 8·5 months (95% CI 7·6-9·3) in the SOX group and 6·7 months (6·2-7·1) in the CapeOX group (hazard ratio, 0·79 [95% CI 0·60-1·04]; p(non-inferiority)<0·0001, p(log-rank)=0·09). The upper limit of the CI was below the predefined margin of 1·43, showing the non-inferiority of SOX to CapeOX. We recorded a higher incidence of grade 3-4 neutropenia (49 [29%] vs 24 [15%]), thrombocytopenia (37 [22%] vs 11 [7%]), and diarrhoea (16 [10%] vs seven [4%]) in the SOX group than in the CapeOX group. The frequency of any grade of hand-foot syndrome was greater in the CapeOX group than it was in the SOX group (51 [31%] vs 23 [14%]).nnnINTERPRETATIONnThe SOX regimen could be an alternative first-line doublet chemotherapy strategy for patients with metastatic colorectal cancer. Further investigation is needed to explore its potential when used together with other targeted agents or as adjuvant chemotherapy.nnnFUNDINGnKorea Healthcare Technology Research and Development Project, Ministry of Health and Welfare, South Korea.

BRCA1 and XRCC1 polymorphisms associated with survival in advanced gastric cancer treated with taxane and cisplatin

This study evaluated the influence of genetic polymorphism influencing drug metabolism on survival in taxane‐ and cisplatin‐treated advanced gastric cancer (AGC). Peripheral blood samples from 207 AGC patients treated with first‐line chemotherapy of taxane and cisplatin were used. We investigated polymorphisms that influenced the metabolism of taxane (ATP‐binding cassette transporter B1 (ABCB1)), cisplatin (glutathione S‐transferase M1 (GSTM1), glutathione S‐transferase P1 (GSTP1), glutathione S‐transferase T1 (GSTT1), excision repair cross complementing 1 (ERCC1), X‐ray Cross Complementing group 3 (XRCC3), X‐ray Cross Complementing group 4 (XRCC4), X‐ray Cross Complementing group 1 (XRCC1), breast cancer (BRCA1)), and 5‐fluorouracil (methylene tetrahydrofolate reductase (MTHFR), thymidylate synthase (TYMS)). A total of 207 patients were enrolled between May 2004 and Dec 2008, and 200 patients were analyzed. The overall response rate was 38.5%. Time to progression and overall survival time were 4.3u2003±u20030.19u2003months and 11.9u2003±u20031.05u2003months, respectively. There was no significant association between genetic polymorphism and response rate. However, the BRCA1 mutant TT homozygote was associated with significant prolongation of overall survival (hazard ratio [HR]u2003=u20030.43; 95% confidence interval [CI], 0.20–0.92; Pu2003=u20030.03) and progression‐free survival (HRu2003=u20030.51; 95% CI, 0.26–1.00; Pu2003=u20030.05). Also, the XRCC1 194 CT genotype was associated with inferior overall survival, relative to the XRCC1 194 CC homozygotes (HRu2003=u20031.49; 95% CI, 0.11–2.07; Pu2003=u20030.018).These findings suggest that BRCA1 TT and XRCC1 194 CT genotypes could be modest prognostic markers of AGC response in taxane‐ and cisplatin‐treated patients.

KITENIN recruits Dishevelled/PKCδ to form a functional complex and controls the migration and invasiveness of colorectal cancer cells

Background and aims: KITENIN was previously reported to promote metastasis in mouse colon tumour models; however, the signalling mechanism of KITENIN at the cellular level was unknown. Here the functional role of KITENIN with respect to colorectal cancer (CRC) cell invasion and its expression in CRC tissues were investigated. Methods: The effect of KITENIN on cell motility was analysed in a migration and invasion assay upon its overexpression and knockdown. Immunoprecipitation was used to elucidate binding partners, and immunohistochemistry was used to study expression levels. Results: KITENIN overexpression enhanced the migration of rat intestinal epithelial cells, whereas a loss of invasiveness was observed in CRC cells after KITENIN knockdown. Mechanically, KITENIN served as a scaffolding molecule that simultaneously recruited both Dishevelled (Dvl) and protein kinase Cδ (PKCδ) through the membrane-spanning C-terminal region to form a complex that stimulated extracellular signal-regulated kinase (ERK)/activating protein-1 (AP-1) via a PKCδ component but also organised the actin filament via a Dvl component. The KITENIN complex controlled the invasiveness of CRC cells aetiologically harbouring various mutations in APC, β-catenin or K-ras, in which AP-1 activation is redundant but the organisation of the actin filament is indispensable for cell motility. Clinically, KITENIN expression was significantly higher in colon cancer tissues from advanced stage (III, IV) than that of stage I CRC and also in corresponding metastatic tissues. Conclusions: The functional KITENIN complex acts as an executor with regard to cell motility and thereby controls CRC cell invasion, which may contribute to promoting metastasis.

Phase II study of docetaxel, cisplatin, and 5-FU induction chemotherapy followed by chemoradiotherapy in locoregionally advanced nasopharyngeal cancer

PurposeThis study sought to determine the feasibility and safety of induction chemotherapy with docetaxel, cisplatin, and 5-fluorouracil (5-FU) triple combination chemotherapy (TPF) followed by concurrent chemoradiotherapy (CCRT) for locoregionally advanced nasopharyngeal cancer (NPC).MethodsPatients with advanced NPC were treated with three cycles of induction chemotherapy. Docetaxel (70xa0mg/m2) and cisplatin (75xa0mg/m2) were given on day 1, followed by 5-FU (1,000xa0mg/m2) as a continuous infusion for 4xa0days. After induction chemotherapy, cisplatin was given at a dose of 100xa0mg/m2 every 3xa0weeks with radiotherapy.ResultsThirty-three patients were enrolled; all patients were stage III (nxa0=xa04, 12.1%) or IV (nxa0=xa029, 87.9%). Among the patients, 32 patients completed both induction TPF therapy and CCRT, with responses as follows: five patients (15.2%) achieved a complete response (CR), and 27 patients (81.8%) a partial response (PR). At 6xa0weeks after CCRT, 23 patients (69.7%) had a CR and 9 patients (27.3%) a PR. The 3-year progression-free survival was 75.6% and the 3-year overall survival was 86.1%. Neutropenia (72.7%), febrile neutropenia (9.1%), and nausea (9.1%) were the most severe toxicities (grade 3–4) during induction chemotherapy, and mucositis (39.4%), fatigue (15.2%), and nausea (9.1%) were the most common toxicities (grade 3–4) during CCRT.ConclusionsAlthough most patients had stage IV NPC, the TPF induction chemotherapy followed by CCRT showed promising activity with manageable toxicity. These results demonstrated the possibility of effective treatment with the aim of not only a palliative, but also a curative, approach to the treatment of advanced NPC.

Docetaxel-loaded thermoresponsive conjugated linoleic acid-incorporated poloxamer hydrogel for the suppression of peritoneal metastasis of gastric cancer.

We evaluated the potential of a thermoresponsive hydrogel consisting of conjugated linoleic acid-coupled Pluronic F-127 (Plu-CLA) as a controlled release, intraperitoneal delivery system for docetaxel with the aim of treating peritoneal dissemination of gastric cancer. Previously, we established a peritoneal metastasis model that involves the injection of BALB/c mice with TMK1 human gastric cancer cells. One week after the TMK1 cells were injected, the mice were injected intraperitoneally with docetaxel alone or docetaxel-loaded Plu-CLA. Tumor progression and response to therapy were monitored by micro-positron emission tomography. The total number of peritoneal tumors and the ascites volume were also measured. Compared with docetaxel alone, the combination of docetaxel and Plu-CLA (docetaxel-Plu-CLA) significantly and synergistically reduced tumor cell survival. Docetaxel-Plu-CLA showed excellent anti-tumor activity, inducing apoptosis more potently than docetaxel alone. Docetaxel-Plu-CLA also significantly reduced the number of peritoneal metastatic nodules and increased survival in the peritoneal gastric cancer xenograft model. Our results show that intraperitoneal administration of docetaxel-Plu-CLA synergistically inhibits peritoneal metastasis and prolongs survival in a peritoneal gastric cancer model. Therefore, Plu-CLA is a potential intraperitoneal-route carrier for hydrophobic docetaxel for the effective treatment of peritoneal metastatic gastric cancer.

Concurrent chemoradiotherapy with S-1 and cisplatin in advanced esophageal cancer

How best to manage advanced esophageal cancer remains unresolved, especially in palliative care. Here, in a pilot study, we evaluated the efficacy and safety of concurrent chemoradiotherapy with S-1 and cisplatin in advanced esophageal cancer. Patients with locally advanced or metastatic squamous cell carcinoma of the esophagus received S-1 and cisplatin at doses of 70 mg/m(2)/day for 14 days and 70 mg/m(2) on day 1, respectively, every 3 weeks. Concurrently, radiotherapy was started at a dose of 200 cGy/day, up to a total of 5400 cGy. After concurrent chemoradiotherapy, additive chemotherapy was repeated up to six cycles. Thirty patients were enrolled in this study; of the 27 in whom efficacy could be evaluated, an objective response rate was seen in 20 (74.1%), including five (18.5%) complete pathologic responses in primary lesions. Improvement of dysphagia was seen in 21 (76%) patients. In patients with stage II or III esophageal cancer, the median progression-free survival and overall survival were 10.6 +/- 0.6 months (95% CI: 9.4-11.8) and 23.0 +/- 5.1 months (95% CI: 13.0-32.9), respectively. In patients with stage IV esophageal cancer, the median progression-free survival and overall survival were 5.4 +/- 1.6 months (95% CI: 2.2-8.6) and 11.6 +/- 1.6 months (95% CI: 8.4-14.8), respectively. The main hematological toxicity was neutropenia, but no neutropenic fever was observed. The major non-hematological toxicities were asthenia and vomiting, mostly of grades 1 and 2. Thus, concurrent chemoradiotherapy with S-1 and cisplatin may be a promising nonsurgical treatment in advanced esophageal cancer.

Glycoprotein 90K, downregulated in advanced colorectal cancer tissues, interacts with CD9/CD82 and suppresses the Wnt/β-catenin signal via ISGylation of β-catenin

Background and aims 90K, a tumour-associated glycoprotein, interacts with galectins and has roles in host defence by augmenting the immune response, but the serum 90K level was suggested to indicate poor prognosis in several cancers. The cellular mechanisms of 90K action on colorectal cancer (CRC) cell motility and its effect on CRC progression were investigated. Methods The impact of 90K was analysed by combining cell cultures, in vitro assays, and immunohistochemistry. Results Secreted 90K suppresses CRC cell invasion, but this action of 90K is masked through binding with extracellular galectins. A novel pathway is identified comprising a secretory 90K and a CD9/CD82 tetraspanin web; in this pathway, 90K interacts with CD9/CD82, suppresses the Wnt/β-catenin signal via a novel proteasomal-ubiquitination mechanism of β-catenin that is dependent on ISG15 (interferon-stimulated gene-15) modification (ISGylation) but not on glycogen synthase kinase 3β (GSK-3β) and Siah/Adenomatous polyposis coli (APC). In a syngeneic mouse colon tumour model, tumour growth and lung metastasis were increased with 90K knockdown. In colon tissues from stage IV human CRC and invading cancer cells of corresponding metastatic liver tissues, in which β-catenin and galectin expression was higher, immunostained 90K and CD9/CD82 were lower than in adjacent hepatic tissues or colon tissues from stage I. Conclusions 90K itself has antitumour activity in CRC cells via suppression of Wnt signalling with a novel mechanism of ISGylation-dependent ubiquitination of β-catenin when it interacts with CD9/CD82, but is downregulated in advanced CRC tissues. The data suggest a strategy of strengthening this novel pathway with concomitant knockdown of galectins as a potential therapeutic approach to CRC progression.

All-trans-retinoic acid (ATRA)-grafted polymeric gene carriers for nuclear translocation and cell growth control

Polyethyleneimine (PEI)-g-All-trans-retinoic acid (ATRA) (designated as PRA) was synthesized as a gene carrier. ATRA at its low concentration is known to be linked to nuclear translocation and cell cycle control (either proliferation or growth arrest) depending on its binding protein in cells. The cytotoxicity of PRA conjugates was lower than that of PEI and was gradually reduced as increasing ATRA graft ratios. The resulting nanosized and positively charged PRA/pDNA complexes showed lower transfection efficiency than the PEI/pDNA complexes (N/P=10) against NIH3T3 which is less sensitive to ATRA in cell growth and more sensitive HeLa cells. However, when a mixed gene complex of PEI and PRA was applied in an effort to reduce the ATRA contents, their NIH3T3 transfection evidenced effective nuclear translocation and induced 2- to 4-fold better transfection efficiency as compared with the PEI/pDNA complexes. When the PEI/pDNA complexes were utilized to transfect HeLa cells, free ATRA treatment reduced their cellular uptake and transfection efficiency. These findings show that the NIH3T3 cells against ATRA-mediated growth arrest would not damage the PRA-mediated transfection enhancement resulting from the facilitated nuclear translocation of polyplexes or pDNA. The more ATRA-sensitivity in growth arrest of HeLa cells would reduce the transfection efficiency of ATRA-incorporated polyplexes. The transfection capability of gene by newly synthesized PRA conjugates to cells is differentiated by their ATRA-sensitivity to nuclear translocation and cell growth control.

Hemolytic Anemia as a Sequela of Arsenic Intoxication Following Long-Term Ingestion of Traditional Chinese Medicine

We report on a 51-yr-old woman who developed intravascular hemolytic anemia caused by arsenic after long-term ingestion of a traditional Chinese medicine (TCM). Twelve years before the admission, she was diagnosed as neurocysticercosis. She has ingested a TCM for about 12 yr instead of undergoing medical therapy for the disease. She was presented with a severe Coombs-negative hemolytic anemia with hemosiderinuria. The urine arsenic level was elevated suggesting the arsenic intoxication as a cause of the anemia. She was treated successfully with therapeutic red cell exchange without any sequelae.