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1.  Prone-position thoracoscopic resection of posterior mediastinal lymph node metastasis from rectal cancer 
Mediastinal lymph node metastasis from colorectal cancer is rare, and barely any reports have described resection of this pathology. We report herein a successful thoracoscopic resection of mediastinal lymph node metastasis in a prone position. A 65-year-old man presented with posterior mediastinal lymph node metastasis after resection of the primary rectal cancer and metachronous hepatic metastasis. Metastatic lymph nodes were resected completely using thoracoscopic surgery in the prone position, which provided advantages of minimal invasiveness, good surgical field, and reduced ergonomic burden on the surgeon. Thoracoscopic resection in the prone position was thought to have the potential to become the standard procedure of posterior mediastinal tumors.
PMCID: PMC4330938
Thoracoscopic resection; Prone position; Mediastinal lymph node metastasis; Colorectal cancer
2.  Molecular diagnosis and therapy for occult peritoneal metastasis in gastric cancer patients 
World Journal of Gastroenterology : WJG  2014;20(47):17796-17803.
To apply an individualized oncological approach to gastric cancer patients, the accurate diagnosis of disease entities is required. Peritoneal metastasis is the most frequent mode of metastasis in gastric cancer, and the tumor-node-metastasis classification includes cytological detection of intraperitoneal cancer cells as part of the staging process, denoting metastatic disease. The accuracy of cytological diagnosis leaves room for improvement; therefore, highly sensitive molecular diagnostics, such as an enzyme immunoassay, reverse transcription polymerase chain reaction, and virus-guided imaging, have been developed to detect minute cancer cells in the peritoneal cavity. Molecular targeting therapy has also been spun off from basic research in the past decade. Although conventional cytology is still the mainstay, novel approaches could serve as practical complementary diagnostics to cytology in near future.
PMCID: PMC4273130  PMID: 25548478
Gastric cancer; Peritoneal lavage; Cytology; Molecular diagnostic techniques; Reverse transcriptase polymerase chain reaction; Carcinoembryonic antigen
3.  Antiproliferative effect of a novel mTOR inhibitor temsirolimus contributes to the prolonged survival of orthotopic esophageal cancer-bearing mice 
Cancer Biology & Therapy  2013;14(3):230-236.
Esophageal squamous cell carcinoma (ESCC) remains one of the most aggressive cancers with poor prognosis regardless of a several reports that indicate a better therapeutic efficacy using some new chemotherapeutic agents. Recent drug development has contributed to an improved specificity to suppress mTOR activity by which many types of malignancies can be explosively progressed. Temsirolimus (CCI-779, TricelTM) is one of recently synthesized analogs of rapamycin and has provided better outcomes for patients with renal cell carcinoma. In this study, we experimentally evaluated an efficacy of targeting mTOR by temsirolimus for ESCC treatment, with an assessment of its survival advantage using an advanced ESCC animal model.
First, we confirmed that the expression of phosphorylated mTOR was increased in 46 of 58 clinical ESCC tumor tissues (79.3%) and appeared to get strengthened with tumor progression. All of ESCC cell lines used in this study revealed an increase of mTOR phosphorylation, accompanied with the upregulation of hypoxia inducible factor-I α (HIF-1α), one of the critical effectors regulated by mTOR. Temsirolimus treatment apparently suppressed the activation of mTOR and its downstream effectors, resulting in the reduced ability of ESCC cell proliferation. Finally, the weekly administration of temsirolimus significantly diminished the size of subcutaneous tumors (vehicle, 3261.6 ± 722.0; temsirolimus, 599.2 ± 122.9; p = 0.007) in nude mice and effectively prolonged orthotopic esophageal cancer-bearing mice (median survival periods: control, 31 d; temsirolimus, 43 d; p = 0.0024).
These data suggests that targeting mTOR by temsirolimus may become a therapeutic alternative for esophageal cancer, with a contribution to a better outcome.
PMCID: PMC3595305  PMID: 23291985
temsirolimus; esophageal cancer; mTOR; prolonged survival; molecular-targeted therapy
4.  Hypoxia activates the cyclooxygenase-2–prostaglandin E synthase axis 
Carcinogenesis  2009;31(3):427-434.
Hypoxia-inducible factors (HIFs), in particular HIF-1α, have been implicated in tumor biology. However, HIF target genes in the esophageal tumor microenvironment remain elusive. Gene expression profiling was performed upon hypoxia-exposed non-transformed immortalized human esophageal epithelial cells, EPC2-hTERT, and comparing with a gene signature of esophageal squamous cell carcinoma (ESCC). In addition to known HIF-1α target genes such as carbonic anhydrase 9, insulin-like growth factor binding protein-3 (IGFBP3) and cyclooxygenase (COX)-2, prostaglandin E synthase (PTGES) was identified as a novel target gene among the commonly upregulated genes in ESCC as well as the cells exposed to hypoxia. The PTGES induction was augmented upon stabilization of HIF-1α by hypoxia or cobalt chloride under normoxic conditions and suppressed by dominant-negative HIF-1α. Whereas PTGES messenger RNA (mRNA) was negatively regulated by normoxia, PTGES protein remained stable upon reoxygenation. Prostaglandin E2 (PGE2) biosynthesis was documented in transformed human esophageal cells by ectopic expression of PTGES as well as RNA interference directed against PTGES. Moreover, hypoxia stimulated PGE2 production in a HIF-1α-dependent manner. In ESCC, PTGES was overexpressed frequently at the mRNA and protein levels. Finally, COX-2 and PTGES were colocalized in primary tumors along with HIF-1α and IGFBP3. Activation of the COX-2–PTGES axis in primary tumors was further corroborated by concomitant upregulation of interleukin-1β and downregulation of hydroxylprostaglandin dehydrogenase. Thus, PTGES is a novel HIF-1α target gene, involved in prostaglandin E biosynthesis in the esophageal tumor hypoxic microenvironment, and this has implications in diverse tumors types, especially of squamous origin.
PMCID: PMC2832548  PMID: 20042640
5.  Glutamine depletion induces murine neonatal melena with increased apoptosis of the intestinal epithelium 
AIM: To investigate the possible biological outcome and effect of glutamine depletion in neonatal mice and rodent intestinal epithelial cells.
METHODS: We developed three kinds of artificial milk with different amounts of glutamine; Complete amino acid milk (CAM), which is based on maternal mouse milk, glutamine-depleted milk (GDM), and glutamine-rich milk (GRM). GRM contains three-fold more glutamine than CAM. Eighty-seven newborn mice were divided into three groups and were fed with either of CAM, GDM, or GRM via a recently improved nipple-bottle system for seven days. After the feeding period, the mice were subjected to macroscopic and microscopic observations by immunohistochemistry for 5-bromo-2’-deoxyuridine (BrdU) and Ki-67 as markers of cell proliferation, and for cleaved-caspase-3 as a marker of apoptosis. Moreover, IEC6 rat intestinal epithelial cells were cultured in different concentrations of glutamine and were subject to a 4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate cell proliferation assay, flow cytometry, and western blotting to examine the biological effect of glutamine on cell growth and apoptosis.
RESULTS: During the feeding period, we found colonic hemorrhage in six of 28 GDM-fed mice (21.4%), but not in the GRM-fed mice, with no differences in body weight gain between each group. Microscopic examination showed destruction of microvilli and the disappearance of glycocalyx of the intestinal wall in the colon epithelial tissues taken from GDM-fed mice. Intake of GDM reduced BrdU incorporation (the average percentage of BrdU-positive staining; GRM: 13.8%, CAM: 10.7%, GDM: 1.14%, GRM vs GDM: P < 0.001, CAM vs GDM: P < 0.001) and Ki-67 labeling index (the average percentage of Ki-67-positive staining; GRM: 24.5%, CAM: 22.4% GDM: 19.4%, GRM vs GDM: P = 0.001, CAM vs GDM: P = 0.049), suggesting that glutamine depletion inhibited cell proliferation of intestinal epithelial cells. Glutamine deprivation further caused the deformation of the nuclear membrane and the plasma membrane, accompanied by chromatin degeneration and an absence of fat droplets from the colonic epithelia, indicating that the cells underwent apoptosis. Moreover, immunohistochemical analysis revealed the appearance of cleaved caspase-3 in colonic epithelial cells of GDM-fed mice. Finally, when IEC6 rat intestinal epithelial cells were cultured without glutamine, cell proliferation was significantly suppressed after 24 h (relative cell growth; 4 mmol/L: 100.0% ± 36.1%, 0 mmol/L: 25.3% ± 25.0%, P < 0.05), with severe cellular damage. The cells underwent apoptosis, accompanied by increased cell population in sub-G0 phase (4 mmol/L: 1.68%, 0.4 mmol/L: 1.35%, 0 mmol/L: 5.21%), where dying cells are supposed to accumulate.
CONCLUSION: Glutamine is an important alimentary component for the maintenance of intestinal mucosa. Glutamine deprivation can cause instability of the intestinal epithelial alignment by increased apoptosis.
PMCID: PMC3042649  PMID: 21390141
Glutamine; Newborn mice; Artificial milk; Melena; Intestinal epithelial cells; Apoptosis
6.  IGF-IR and its inhibitors in gastrointestinal carcinomas (Review) 
Oncology Letters  2010;1(1):195-201.
The type I insulin-like growth factor receptor (IGF-IR) and its associated signaling system play a significant role in tumorigenesis, tumor survival and progression, and cancer therapeutic resistance, and thus has provoked great interest as a promising target for cancer treatment. In this report we present the role of IGF-IR in gastrointestinal carcinomas whose pathology has been identified as tightly correlated with an abnormal expression and activation of IGF-IR. Reported data from experimental studies suggest the feasibility of targeted IGF-IR therapy in gastrointestinal carcinomas. Many types of inhibitors against IGF-IR have been developed. Inhibitors with anti-IGF-IR monoclonal antibodies and tyrosine kinase inhibitors currently undergoing preclinical and clinical evolution are also reviewed.
PMCID: PMC3436207  PMID: 22966282
type I insulin-like growth factor receptor; monoclonal antibody; tyrosine kinase inhibitor; gastrointestinal carcinoma; cancer therapy
7.  Progress in researches about focal adhesion kinase in gastrointestinal tract 
Focal adhesion kinase (FAK) is a 125-kDa non-receptor protein tyrosine. Growth factors or the clustering of integrins facilitate the rapid phosphorylation of FAK at Tyr-397 and this in turn recruits Src-family protein tyrosine kinases, resulting in the phosphorylation of Tyr-576 and Tyr-577 in the FAK activation loop and full catalytic FAK activation. FAK plays a critical role in the biological processes of normal and cancer cells including the gastrointestinal tract. FAK also plays an important role in the restitution, cell survival and apoptosis and carcinogenesis of the gastrointestinal tract. FAK is over-expressed in cancer cells and its over-expression and elevated activities are associated with motility and invasion of cancer cells. FAK has been proposed as a potential target in cancer therapy. Small molecule inhibitors effectively inhibit the kinase activity of FAK and show a potent inhibitory effect for the proliferation and migration of tumor cells, indicating a high potential for application in cancer therapy.
PMCID: PMC2795178  PMID: 20014455
Focal adhesion kinase; Restitution; Survival and apoptosis; Cancer; Inhibitor

Results 1-7 (7)