Impact of Six Consecutive Days of Sprint Training in Hypoxia on Performance in Competitive Sprint Runners.

Kasai, N, Mizuno, S, Ishimoto, S, Sakamoto, E, Maruta, M, Kurihara, T, Kurosawa, Y, and Goto, K. Impact of six consecutive days of sprint training in hypoxia on performance in competitive sprint runners. J Strength Cond Res 33(1): 36-43, 2019-The purpose of this study was to determine the effects of 6 successive days of repeated sprint (RS) training in moderate hypoxia on anaerobic capacity in 100-200-m sprint runners. Eighteen male sprint runners (age, 20.0 ± 0.3 years; height, 175.9 ± 1.1 cm; and body mass, 65.0 ± 1.2 kg) performed repeated cycling sprints for 6 consecutive days in either normoxic (NOR; fraction of inspired oxygen [FiO2], 20.9%; n = 9) or hypoxic conditions (HYPO; FiO2, 14.5%; n = 9). The RS ability (10 × 6-second sprints), 30-second maximal sprint ability, maximal oxygen uptake ((Equation is included in full-text article.)max), and 60-m running time on the track were measured before and after the training period. Intramuscular phosphocreatine (PCr) content (quadriceps femoris muscle) was measured by P-magnetic resonance spectroscopy (P-MRS) before and after the training period. Both groups showed similar improvements in RS ability after the training period (p < 0.05). Power output during the 30-second maximal sprint test and (Equation is included in full-text article.)max did not change significantly after the training period in either group. Running time for 0-10 m improved significantly after the training period in the HYPO only (before, 1.39 ± 0.01 seconds; after, 1.34 ± 0.02 seconds, p < 0.05). The HYPO also showed a significant increase in intramuscular PCr content after the training period (before, 31.5 ± 1.3 mM; after, 38.2 ± 2.8 mM, p < 0.05). These results suggest that sprint training for 6 consecutive days in hypoxia or normoxia improved RS ability in competitive sprint runners.

Muscle RAS oncogene homolog (MRAS) recurrent mutation in Borrmann type IV gastric cancer.

The prognosis of patients with Borrmann type IV gastric cancer (Type IV) is extremely poor. Thus, there is an urgent need to elucidate the molecular mechanisms underlying the oncogenesis of Type IV and to identify new therapeutic targets. Although previous studies using whole-exome and whole-genome sequencing have elucidated genomic alterations in gastric cancer, none has focused on comprehensive genetic analysis of Type IV. To discover cancer-relevant genes in Type IV, we performed whole-exome sequencing and genome-wide copy number analysis on 13 patients with Type IV. Exome sequencing identified 178 somatic mutations in protein-coding sequences or at splice sites. Among the mutations, we found a mutation in muscle RAS oncogene homolog (MRAS), which is predicted to cause molecular dysfunction. MRAS belongs to the Ras subgroup of small G proteins, which includes the prototypic RAS oncogenes. We analyzed an additional 46 Type IV samples to investigate the frequency of MRAS mutation. There were eight nonsynonymous mutations (mutation frequency, 17%), showing that MRAS is recurrently mutated in Type IV. Copy number analysis identified six focal amplifications and one homozygous deletion, including insulin-like growth factor 1 receptor (IGF1R) amplification. The samples with IGF1R amplification had remarkably higher IGF1R mRNA and protein expression levels compared with the other samples. This is the first report of MRAS recurrent mutation in human tumor samples. Our results suggest that MRAS mutation and IGF1R amplification could drive tumorigenesis of Type IV and could be new therapeutic targets.

ARHGEF15 overexpression worsens the prognosis in patients with pancreatic ductal adenocarcinoma through enhancing the motility and proliferative activity of the cancer cells.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive neoplastic diseases, associated with a remarkably poor prognosis. However, the molecular mechanisms underlying the development of PDAC remain elusive. The aim of this study was to identify genes whose expressions are correlated with a poor prognosis in PDAC patients, and to unravel the mechanisms underlying the involvement of these genes in the development of the cancer. METHODS: Global gene expression profiling was conducted in 39 specimens obtained from Japanese patients with PDAC to identify genes whose expressions were correlated with a shorter overall survival. The effect of gene silencing or overexpression of ARHGEF15 in pancreatic cancer cell lines was examined by introducing siRNAs of ARHGEF15 or the ARHGEF15 expression vector. After assessing the effect of ARHGEF15 deregulation on the Rho-family proteins by pull-down assay, wound healing, transwell and cell viability assays were carried out to investigate the cellular phenotypes caused by the perturbation. RESULTS: The global mRNA expression profiling revealed that overexpression of ARHGEF15, a Rho-specific GEF, was significantly associated with a poor prognosis in patients with PDAC. We also found that the depletion of ARHGEF15 by RNA interference in pancreatic cancer cell lines downregulated the activities of molecules of the Rho signaling pathway, including RhoA, Cdc42 and Rac1. Then, we also showed that ARHGEF15 silencing significantly reduced the motility and viability of the cells, while its overexpression resulted in the development of the opposite phenotype in multiple pancreatic cancer cell lines. CONCLUSION: These data suggest that upregulation of ARHGEF15 contributes to the development of aggressive PDAC by increasing the growth and motility of the pancreatic cancer cells, thereby worsening the prognosis of these patients. Therefore, ARHGEF15 could serve as a novel therapeutic target in patients with PDAC.

Effect of training in hypoxia on repeated sprint performance in female athletes.

BACKGROUND: This study determined the effect of repeated sprint training in hypoxia (RSH) in female athletes. METHODS: Thirty-two college female athletes performed repeated cycling sprints of two sets of 10 × 7-s sprints with a 30-s rest between sprints twice per week for 4 weeks under either normoxic conditions (RSN group; FiO2, 20.9%; n = 16) or hypoxic conditions (RSH group; FiO2, 14.5%; n = 16). The repeated sprint ability (10 × 7-s sprints) and maximal oxygen uptake ([Formula: see text]) were determined before and after the training period. RESULTS: After training, when compared to pre-values, the mean power output was higher in all sprints during the repeated sprint test in the RSH group but only for the second half of the sprints in the RSN group (P ≤ 0.05). The percentage increases in peak and mean power output between before and after the training period were significantly greater in the RSH group than in the RSN group (peak power output, 5.0 ± 0.7% vs. 1.5 ± 0.9%, respectively; mean power output, 9.7 ± 0.9% vs. 6.0 ± 0.8%, respectively; P < 0.05). [Formula: see text] did not change significantly after the training period in either group. CONCLUSION: Four weeks of RSH further enhanced the peak and mean power output during repeated sprint test compared with RSN.

Comprehensive evaluation of the response of genes to the administration of the antitumor drug S-1 using a low density array.

S-1 is a newly developed dihydropyrimidine dehydrogenase inhibitory fluoropyrimidine that exhibits high clinical efficacy against non-small cell lung cancers. To identify genes that may be associated with chemosensitivity to the antitumor drug S-1, we used a low density array representing 93 genes to analyze expression profiles in 4 orthotopically implanted lung cancers derived from human lung cancer cell lines (Lu99, Lu130, LC6 and A549). The tumor growth inhibition (TGI) rates of S-1 in orthotopically implanted tumors of the Lu99, Lu130, LC6 and A549 cell lines were 34.6, 37.5, 32.1 and 3.6%, respectively. The expression of the PRSS3, ABCC4, TXN, SHMT1 and CMPK genes was significantly promoted in the orthotopically implanted SCID mouse model of the 4 lung cancer cell lines by the administration of S-1, while the expression of the LMO7 and FOLH1 genes was significantly suppressed. The expression of the ABCC1, 2 and TST genes was negatively correlated with TGI. The expression of the TK1 and ERCC2 genes was positively correlated with TGI. The results of the present study suggest that the expression of the ABCC1, 2, TST, TK1 and ERCC2 genes is related to resistance to the antitumor drug S-1.

In vivo evidence for a significant role of folylpolyglutamate synthase in combined chemotherapy with oral fluoropyrimidine, UFT or S-1, and leucovorin.

Combined chemotherapy with 5-fluorouracil and leucovorin (LV) has been widely used for the treatment of patients with colorectal cancer. Given that LV effects are attributable to increased levels of reduced folate in cancer cells, we attempted here to show the in vivo role of folylpolyglutamate synthetase (FPGS), which stabilizes intracellular reduced folate, in the anticancer activities of oral fluoropyrimidines, UFT or S-1, combined with LV. To this end, HCT-15 human colon cancer cells were knocked down for FPGS expression by RNA interference. The cell line stably expressing FPGS shRNA (FPGS shRNA HCT-15) was cloned and transferred subcutaneously into nude mice fed a low-folate diet. FPGS shRNA HCT-15 tumors expressed a significantly lower level of FPGS at protein and mRNA levels than parental HCT-15 cells, and the levels of reduced folate in FPGS shRNA HCT-15 tumors became 57% of those in parent after a single administration of 10 mg/kg of LV. Notably, FPGS downregulation did not affect the tumor growth or sensitivity to fluoropyrimidine. Importantly, we observed that LV given for 14 days failed to enhance the anticancer effects of UFT and S-1 in FPGS shRNA HCT-15. This was in keeping with the results that LV did not increase the ternary complex of TS, FdUMP and reduced folate. In conclusion, the present results provide in vivo evidence that intratumor FPGS plays an important role in the efficacy of oral fluoropyrimidine plus LV therapy for colorectal cancer.

[Early phase medical system review in Kobe 2009 influenza A (H1N1) pandemic].

We discuss the efficacy 3 pandemic influenza, measures planned against an anticipated outbreak. First was an exclusive influenza outpatient clinic. Second was a medical call center for febrile illness subjects needing with fever clinic recommendation. The last was isolation. Before the outbreak, we had thought that all confirmed or suspected new influenza case should be quarantined. May 2009 brought the first A1/H1 pandemic influenza outbreak to Kobe, Japan. After the first infection announcement, call center and fever clinic consultations skyrocketed, filling all 55 designated Kobe hospital bed within 48 hours. Inquiries at call centers increased more rapidly than numbers of subjects rushing to fever clinics. Just after designated hospital beds were filled, medical service restrictions were rapidly relaxed. Our experiences suggest that compulsory hospitalization broke down quickest in the fever case overflow, so medical call centers may be crucial in preventing fever clinic overflows by subjects with fever of unknown origin not recommended to consult fever clinics. Those with severe influenza symptoms should be given priority in hospitalization and flexible policies are recommended.

Molecular determinants of folate levels after leucovorin administration in colorectal cancer.

PURPOSE: Oral leucovorin (LV) is used with uracil/tegafur (UFT) in the treatment of colorectal cancer (CRC). In order to find the factors related to the efficacy of LV in enhancing the antitumour effect of UFT, we investigated the relationships between the reduced folate levels in the CRC tissue after LV administration and the gene-expression levels of folate-metabolizing enzymes and folate transporters. METHODS: The subjects were 60 CRC patients, scheduled to undergo surgery. The control group (n = 30) did not receive LV. Three groups (n = 10 for each) received a single dose of oral LV at 25 mg, 4, 12 or 18 h before surgery (LV 4 h, LV 12 h or LV 18 h groups, respectively). The reduced folate levels in plasma and tissues were measured by high-performance liquid chromatography (HPLC) or a thymidylate synthase-FdUMP binding assay, respectively. The intratumoral expression levels of 34 genes were quantitatively evaluated with a real-time polymerase chain reaction (RT-PCR) assay. RESULTS: The reduced folate levels persisted for a longer period of time in the CRC tissue than in the plasma after LV administration. A multivariate logistic regression analysis revealed that high folylpolyglutamate synthase (FPGS) gene expression, low gamma-glutamyl hydrolase (GGH) gene expression and low ATP-binding cassette sub-family C, number 1 (ABCC1) gene expression in CRC tissues were predictive factors for a high reduced folate level after LV administration. CONCLUSIONS: The expression level of FPGS, GGH and ABCC1 in CRC tissues could predict the reduced folate level after LV administration, and these factors may determine the efficacy of LV treatment.

Effect of leucovorin on the antitumor efficacy of the 5-FU prodrug, tegafur-uracil, in human colorectal cancer xenografts with various expression levels of thymidylate synthase.

The combination of oral tegafur-uracil (UFT) with leucovorin (LV) is used to treat patients with stage II to III colon cancer based on the results of postoperative randomized studies in which UFT/LV treatment showed an equivalent efficacy to intravenous 5-FU plus LV therapy. However, whether the addition of LV to UFT can elevate the antitumor activity of UFT in colorectal tumors with high expression levels of thymidylate synthase (TS), which affects 5-FU efficacy, remains to be clarified. This study investigated the effect of LV on the antitumor activity of UFT and/or 5-FU prodrugs in low folate diet-fed nude mice using human colorectal cancer xenografts with various expression levels of TS. The addition of LV to UFT resulted in a 55-79% inhibition of tumor growth among 11 types of colorectal tumor xenograft, whereas UFT alone showed 23-67% antitumor activity. Although there was an inverse relationship between the antitumor effect of UFT alone and UFT plus LV and tumoral TS activity, UFT plus LV appeared to have a more potent antitumor effect than UFT alone on colorectal tumors such as Co-3 and KM12C/5-FU with high expression levels of TS. This finding was confirmed by the significant positive correlation between the relative inhibition ratio of UFT/LV to UFT alone and TS levels in tumors. To investigate the reason for the higher efficacy of UFT/LV on colorectal cancer xenografts with high TS activity, intratumoral levels of reduced folates and a ternary complex of TS after oral UFT with or without LV were measured using Co-3 xenografts. Elevated levels of reduced folates and an increased ternary complex of TS in LV-treated tumors were noted. Our results indicate that a combined therapy of UFT with LV may contribute to the treatment of colorectal cancer patients with low and high expression levels of tumoral TS by increased formation of the ternary complex of TS leading to potentiated antitumor efficacy of UFT.

Gene expression signature for recurrence in stage III colorectal cancers.

BACKGROUND: Colorectal cancer patients with lymph node metastases (stage III) show poorer prognosis than those without. Predicting development of recurrence may guide the need for intensive follow-up and/or adjuvant chemotherapy in such patients. The authors' objective was to identify a set of discriminating genes that could predict recurrence in stage III colorectal cancer. METHODS: Thirty-six stage III colorectal cancer patients were studied. Tumor samples were obtained from surgically resected specimens. Thirteen patients developed recurrence, whereas 23 patients did not. Gene expression profiles were determined using human HG-U133 Plus 2.0 Gene Chip (Affymetrix, Santa Clara, Calif). RESULTS: The authors identified 45 discriminating genes between patients with and without recurrence. By using this gene set, they established a new model to predict recurrence with an accuracy of 90.9%. The discriminating genes included calcineurin-binding protein 1 (CABIN1), whose expression differed remarkably between patients with and without recurrence (P=.0073). The authors further examined the DNA copy number of CABIN1 and were able to show a significant relation with recurrence (P<.012). Patients having CABIN1 gene loss demonstrated a higher risk of recurrence (odds ratio, 18.8). DNA copy number of CABIN1 alone could predict recurrence with an accuracy of 80.0%. CONCLUSIONS: The results of the current study demonstrated that gene expression profiling is useful in predicting recurrence in stage III colorectal cancer. The authors identified CABIN1 among discriminating genes that may play a key role in the development of recurrence. These results may help to establish an individualized therapy for stage III colorectal cancer.

Folylpolyglutamate synthase and gamma-glutamyl hydrolase regulate leucovorin-enhanced 5-fluorouracil anticancer activity.

Although 5-fluorouracil (5-FU) plus leucovorin (LV) is a standard chemotherapy regimen for colorectal cancer, the factors that determine the LV-mediated enhancement of the antitumor activity of 5-FU have remained unknown. We investigated the roles of folylpolyglutamate synthase (FPGS) and gamma-glutamyl hydrolase (GGH), which are the main enzymes involved in folate metabolism, in the effect of LV. LV enhanced the anticancer activity of 5-FU and the level of reduced folate in human colon cancer cells. Small-interfering RNA (siRNA) transfected into DLD-1 cells to downregulate FPGS reduced the basal level of reduced folate, the folate level after LV treatment, and the enhancement of 5-fluoro-2'-deoxyuridine (FdUrd)-induced cytotoxicity elicited by LV. By contrast, the downregulation of GGH by siRNA increased cellular sensitivity to FdUrd combined with LV. These results suggest that FPGS and GGH expression levels in tumors are determinants of the efficacy of LV in enhancing the antitumor activity of 5-FU.

Orotate phosphoribosyltransferase expression level in tumors is a potential determinant of the efficacy of 5-fluorouracil.

Although the intratumoral expression levels of thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) are known to affect the antitumor activity of 5-fluorouracil (5-FU), the importance of orotate phosphoribosyltransferase (OPRT) has remained unclear. This study investigated the relationship between intratumoral OPRT expression and the antitumor activity of 5-FU using human NCI60 cell lines with similar levels of TS and DPD messenger RNAs, as well as 31 tumor xenografts. The OPRT mRNA level was positively correlated with the 5-FU efficacy in these cell lines. In vitro, the 50% growth-inhibitory concentrations of 5-FU were closely correlated with the OPRT mRNA levels in cancer cell lines with similar levels of TS mRNAs when combined with a DPD inhibitor. Moreover, downregulation of OPRT with small-interfering RNA decreased the sensitivities of the cultured tumor cells to 5-FU. These results suggest that the OPRT expression level in tumors is an additional determinant of the efficacy of 5-FU.