S-1 plus irinotecan and oxaliplatin for the first-line treatment of patients with metastatic colorectal cancer: a prospective phase II study and pharmacogenetic analysis

BACKGROUND

S-1 is an oral fluoropyrimidine that mimics infusional 5-fluorouracil. The aim of this phase II trial was to explore the clinical efficacy of the triplet regimen TIROX, which consists of S-1, irinotecan and oxaliplatin.

METHODS

Forty-two chemo-naive patients with metastatic colorectal cancer (mCRC) were planned to be enrolled and be treated with irinotecan 150 mg m(-2) followed by oxaliplatin 85 mg m(-2) on day 1 and S-1 80 mg m(-2) per day from day 1 to 14 every 3 weeks. Polymorphisms in the UGT1A1, UGT1A6, UGT1A7 and CYP2A6 genes were analysed.

RESULTS

Between July 2007 and February 2008, 43 patients were enrolled. An objective response was noted in 29 patients (67.4%, 95% confidence interval: 53.4-81.4), of which 2 achieved durable complete responses. The median progression-free survival was 10.0 months and the median overall survival was 19.2 months. Significant grade 3 or 4 adverse events were neutropenia (45.2%), febrile neutropenia (9.5%), diarrhoea (7.1%) and vomiting (9.5%). Increased gastrointestinal toxicities were associated with the presence of UGT1A6*2 or UGT1A7*3 and an improved tumour response was noted in those without variant alleles of CYP2A6 or UGT1A1*60.

CONCLUSION

The combination of S-1, irinotecan and oxaliplatin showed favourable efficacy and tolerability in untreated patients with mCRC.

Percolated pore networks of oxygen plasma-activated multi-walled carbon nanotubes for fast response, high sensitivity capacitive humidity sensors

We report on the preparation of capacitive-type relative humidity sensors incorporating plasma-activated multi-wall carbon nanotube (p-MWCNT) electrodes and on their performance compared with existing commercial technology. Highly open porous conductive electrodes, which are almost impossible to obtain with conventional metal electrodes, are fabricated by spray-depositing MWCNT networks on a polyimide layer. Oxygen plasma activation of the MWCNTs is also explored to improve the water adsorption of the MWCNT films, by introducing oxygen-containing functional groups on the CNT surface. Polyimide humidity sensors with optimized p-MWCNT network electrodes exhibit exceptionally fast response times (1.5 for adsorption and 2 s for desorption) and high sensitivity (0.75 pF/% RH). These results may be partially due to their percolated pore structure being more accessible for water molecules, expending the diffusion of moisture to the polyimide sensing film, and partially due to the oxygenated surface of p-MWCNT films, allocating more locations for adsorption or attraction of water molecules to contribute to the sensitivity.

Effect of complementary and alternative medicine on the survival and health-related quality of life among terminally ill cancer patients: a prospective cohort study

BACKGROUND

We evaluated whether complementary and alternative medicine (CAM) use influenced outcomes [survival and health-related quality of life (HRQOL)] of cancer patients whose condition had just been judged terminal.

PATIENTS AND METHODS

From July 2005 to October 2006, we conducted a prospective cohort study of 481 terminally ill cancer patients at 11 university hospitals and the National Cancer Center in Korea. We assessed how the use of CAM affected HRQOL and survival.

RESULTS

In a follow-up of 481 patients and 163.8 person-years, we identified 466 deceased cases. On multivariate analyses, CAM users did not have better survival compared with nonusers [adjusted hazard ratio (aHR), 0.91; 95% confidence interval (CI) 0.74-1.10]. Among mind-body interventions, prayer showed significantly worse survival (aHR, 1.56; 95% CI, 1.00-2.43). Clinically, CAM users reported significantly worse cognitive functioning (-11.6 versus -1.3; P < 0.05) and fatigue (9.9 versus -1.0; P < 0.05) than nonusers. Compared with nonusers in subgroup analysis, users of alternative medical treatments, prayer, vitamin supplements, mushrooms, or rice and cereal reported clinically significant worse changes in some HRQOL subscales.

CONCLUSION

While CAM did not provide any definite survival benefit, CAM users reported clinically significant worse HRQOLs.

Abstract P3-12-05: Clinical features and outcomes of leptomeningeal metastasis in patients with breast cancer: a single center experience

Background: Leptomeningeal metastasis (LM) is one of the major problems in managing metastatic breast cancer because of LM typically carries a devastating prognosis and often represents a terminal event. We analyzed the clinical features and outcomes of LM in patients with breast cancer.

Methods: We retrospectively reviewed the medical records of patients who were diagnosed with LM from breast cancer between 2002 and 2012 at Asan Medical Center.

Results: Of the 95 LM patients by cytologically proven (n = 81) or radiologically diagnosed (n = 14), 57 (60%) had an ECOG performance status (PS) ≥ 3, and the median age was 47 years (range, 26–72 years). The patients were diagnosed with LM after a median of 10.3 months (95% CI, 5.5–15.0 months) from the time of diagnosis of metastatic breast cancer. LM was present in 2 patients at the time of initial diagnosis. Twenty-three patients (24.2%) had isolated CNS metastasis, and 6 (6.3%) had only LM without any detectable metastasis sites. At the time of diagnosis of LM, 46 patients (48.4%) presented with coincidental failure of systemic disease control. Seventy-eight patients (82.1%) underwent intrathecal chemotherapy (methotrexate; n=78, thiotepa; n=11), resulting in one-third of cytologic negative conversion (n = 26), and 41 (43.2%) received systemic chemotherapy. The overall median survival time was 3.3 months (95% CI, 2.5–4.2 months) and 7.8% of the patients survived for more than 1 year. Overall survival tended to be better in patients who achieved cytologic negative conversion to intrathecal chemotherapy than those did not (median 4.5 months versus 3.2 months, P = 0.241). Overall survival was not different according to subtypes; hormone receptor (+), HER2 (+), and triple negative (median 3.6 months, 3.3 months, and 3.2 months, P = 0.937). Multivariate analysis demonstrated that ECOG PS ≥ 3 (HR = 2.09, 95% CI 1.21–3.58, P = 0.007), coincidental failure of systemic disease control at LM (HR = 3.01, 95% CI 1.76–5.15, P &lt; 0.001), and systemic chemotherapy after LM (HR = 0.40, 95% CI 0.24–0.68, P = 0.001) were independent factors associated with survival.

Conclusions: The prognosis for patients with LM from breast cancer was still poor. Systemic chemotherapy in addition to intrathecal chemotherapy might confer a survival benefit, even after the detection of LM.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-12-05.

Lymph node ratio is an independent prognostic factor in patients with rectal cancer treated with preoperative chemoradiotherapy and curative resection

PURPOSE

To evaluate the prognostic effect of lymph node ratio (LNR) in patients with locally advanced rectal cancer who were treated with curative resection after preoperative chemoradiotherapy (CRT).

METHODS

Between October 2001 and December 2007, 519 patients who had undergone curative resection of primary rectal cancer after preoperative CRT were enrolled. Of these, 154 patients were positive for lymph node (LN) metastasis and were divided into three groups according to the LNR (≤ 0.15 [n=80], 0.16-0.3 [n=44], >0.3 [n=30]) to evaluate the prognostic effect on overall survival (OS) and disease-free survival (DFS).

RESULTS

LNR (≤ 0.15, 0.16-0.3, and >0.3) was significantly associated with 5-year OS (90.3%, 75.1%, and 45.1%; p<0.001) and DFS (66.7%, 55.8%, and 21.9%; p<0.001) rates. In a multivariate analysis, LNR (≤ 0.15, 0.16-0.3, and >0.3) was a significant independent prognostic factor for OS (hazard ratios [HRs], 1, 3.609, and 8.197; p<0.001) and DFS (HRs, 1, 1.699, and 3.960; p<0.001). LNR had a prognostic impact on OS and DFS in patients with <12 harvested LNs, as well as in those with ≥ 12 harvested LNs (p<0.05).

CONCLUSION

LNR was a significant independent prognostic predictor for OS and DFS in patients with locally advanced rectal cancer who were treated with curative resection after preoperative CRT.

Carotid atherosclerosis in patients with untreated chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is associated with systemic inflammation.

OBJECTIVE

To evaluate carotid artery intima-media thickness (IMT), high sensitivity C-reactive protein (hsCRP) and their correlation in newly diagnosed untreated patients with COPD.

DESIGN

Post-bronchodilator spirometry, carotid artery IMT and blood tests were measured in patients with COPD (COPD group). Age, sex, body mass index, smoking status and smoking amount were compared with matched healthy subjects (non-COPD group). Participants taking medications and/or with a history of hypertension, diabetes mellitus, dyslipidaemia, COPD or cardiovascular disease were excluded.

RESULTS

A total of 126 patients (COPD group 42, non-COPD group 84) were enrolled. The IMT and hsCRP of the COPD group were significantly higher than in the non-COPD group (P < 0.05). The decrease in the forced expiratory volume in 1 second/forced vital capacity (FEV(1)/FVC) ratio and FEV(1) was significantly correlated with an increase in the hsCRP and IMT (P < 0.05); there was no correlation between the IMT and hsCRP (P = 0.152).

CONCLUSION

In newly diagnosed untreated patients with COPD, the carotid artery IMT and hsCRP were significantly higher than in healthy subjects. These findings suggest that systemic inflammation may play a potential role in preclinical atherosclerosis in COPD.

P5-13-11: PTEN and Tau-Protein Expression: Predictive Value of Poor Response to Trastuzumab Plus Paclitaxel in Patients with HER2−Positive Breast Cancer

Backgrounds: Trastuzumab-based chemotherapy has been an active treatment in patients (pts) with HER2−positive breast cancer; however, primary and secondary resistance has occurred in pts treated with trastuzumab (H) alone or in combination with chemotherapy. Material and Methods: Biomarkers were searched using tissue microarrays (TMA) in the HER2−positive breast cancer pts treated with H and paclitaxel (P) combination chemotherapy between October 2004 and August 2010. Tumor blocks of 101 pts were analyzed for VEGF, IGF-1R, p-Akt, beta-III tubulin, CD44, Tau-protein, p27 and PTEN by immunohistochemical (IHC) analysis. Eight biomarkers were assessed to investigate the correlation with the clinical outcomes, including response rate (RR), progression free survival (PFS), and overall survival (OS).

Results: With a median follow-up duration of 21.7 months (range, 9.1−55.2 months), 101 pts received H+P chemotherapy in neoadjuvant setting (n=36, 35.6%) and recurrent or metastatic setting (n=65, 64.4%). Median age was 48 (range, 19–83 years), and the majority of pts (n=95, 94.1%) had good performance status. Premenopausal pts and hormone receptor-negative pts were 48 (47.5%) and 52 (51.5%), respectively. The median cycle of H+P chemotherapy was six (range, H 1–43; P 1–21). Overall RR was 68.3% (n=69) including complete response with 7 pts, and PFS and OS were significantly longer in pts responsive to H+P chemotherapy compared with non-responsive patients (PFS, p=0.001; OS, p=0.015). Although VEGF, IGF-1R, p-Akt, beta-III tubulin, CD44, p27 and PTEN status by IHC were not significantly associated with response to H+P chemotherapy, Tau-protein showed a trend of association without statistical significance (RR, 46.2% vs. 71.6%, p=0.066). Among 13 pts with high Tau protein expression, 9 pts with both high Tau-protein and low PTEN level showed statistically significant lower RR compared with other 92 pts (22.2% vs. 72.8%; p=0.002). None of the biomarkers was related to PFS and OS in pts with recurrent or metastatic disease, and to pathologic complete response in pts after H+P chemotherapy as neoadjuvant therapy.

Conclusion: Our data showed that both low PTEN level and high Tauprotein expression were significantly associated with poor response to H+P chemotherapy in patients with HER2−positive breast cancer.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-13-11.

Abstract P1-01-08: Lymph Node Ratio as an Alternative to pN Staging in Node Positive Breast Cancer: A report from the Korean Breast Cancer Society

Background: To compare the lymph node ratio(LNR) and pN staging as a prognostic predictor and find out high risk subgroup which can not predict prognosis using pN staging.

Patients and Methods: Using information from two large databases, including Korean nationwide registry, we compared the survival using LNR and pN stage parameters by Cox regression analysis. Moreover survival data were analysed according to age subgroups and intrinsic subtypes. Results: In an analysis of 2264 node positive patients from single institution, adjusted cancer specific mortality risks of low (≥0.20), intermediate (&gt;0.20 and ≥0.65) and high risk (&gt;0.65) LNR groups were 1(reference), 1.9 (95%CI, 1.6 to 2.4), 4.6(95%CI, 3.6 to 5.8). The difference of mortality risk between LNR parameters were wider than that of N1, N2 and N3 in DFS, CSS, OS. In contrast to LNR risk categories, survival curve in pN1 and pN2 overlapped in the patients below 35 years old. Survival curve in pN1 and pN2 also overlapped in patients in her2/neu enriched as well as triple negative subtype. These finding were validated by an analysis of nationwide registry data on 15488 node positive patients. The patients who had N1 and LNR2-3 disease showed poor DFS (HR 1.7 95% CI 1.4 to 2.2) and CSS (HR 1.6, 95% CI 1.1 to 2.2) compared with the patients who had N2 and LNR1 disease. Conclusion: LNR define breast cancer prognosis more adequate than the pN categories especially high risk breast cancer like young age, her2/neu enriched and triple negative intrinsic subtype. It is more reasonable that treatment decision like radiotherapy might be depend on the LNR than pN staging. We argue that LNR should be considered as an alternative to pN staging.

Figures available in online version.

Suppression of mitochondrial NADP(+)-dependent isocitrate dehydrogenase activity enhances curcumin-induced apoptosis in HCT116 cells

Curcumin is a polyphenol derived from the plant Curcuma longa that induces apoptotic cell death in malignant cancer cell lines. It has been shown previously that mitochondrial NADP(+)-dependent isocitrate dehydrogenase (IDPm) plays an essential role in defense against oxidative stress by supplying NADPH for antioxidant systems. This study demonstrates that curcumin decreased the activity of IDPm, both as a purified enzyme and in cultured cells. It also shows that curcumin-induced apoptosis in the colon cancer cell line HCT116 is significantly enhanced by suppression of IDPm activity. Transfection of HCT116 cells with an IDPm small interfering RNA (siRNA) markedly decreased activity of IDPm, enhancing cellular susceptibility to curcumin-induced apoptosis, as reflected by DNA fragmentation, cellular redox status, mitochondria dysfunction and modulation of apoptotic marker proteins. Together, these results suggest that application of curcumin together with IDPm siRNA may be an effective combination modality in the treatment of cancer.

Comparison of mammography, sonography, MRI and clinical examination in patients with locally advanced or inflammatory breast cancer who underwent neoadjuvant chemotherapy

OBJECTIVES

The purpose of this study was to determine the relative accuracies of mammography, sonography, MRI and clinical examination in predicting residual tumour size and pathological response after neoadjuvant chemotherapy for locally advanced or inflammatory breast cancer. Each prediction method was compared with the gold standard of surgical pathology.

METHODS

43 patients (age range, 25-62 years; mean age, 42.7 years) with locally advanced or inflammatory breast cancer who had been treated by neoadjuvant chemotherapy were enrolled prospectively. We compared the predicted residual tumour size and the predicted response on imaging and clinical examination with residual tumour size and response on pathology. Statistical analysis was performed using weighted kappa statistics and intraclass correlation coefficients (ICC).

RESULTS

The ICC values between predicted tumour size and pathologically determined tumour size were 0.65 for clinical examination, 0.69 for mammography, 0.78 for sonography and 0.97 for MRI. Agreement between the response predictions at mid-treatment and the responses measured by pathology had kappa values of 0.28 for clinical examination, 0.32 for mammography, 0.46 for sonography and 0.68 for MRI. Agreement between the final response predictions and the responses measured by pathology had kappa values of 0.43 for clinical examination, 0.44 for mammography, 0.50 for sonography and 0.82 for MRI.

CONCLUSION

Predictions of response and residual tumour size made on MRI were better correlated with the assessments of response and residual tumour size made upon pathology than were predictions made on the basis of clinical examination, mammography or sonography. Thus, the evaluation of predicted response using MRI could provide a relatively sensitive early assessment of chemotherapy efficacy.

Immune regulatory effects of simvastatin on regulatory T cell-mediated tumour immune tolerance

Statins are potent inhibitors of hydroxyl-3-methylglutaryl co-enzyme A (HMG-CoA) reductase, and have emerged as potential anti-cancer agents based on preclinical evidence. In particular, compelling evidence suggests that statins have a wide range of immunomodulatory properties. However, little is known about the role of statins in tumour immune tolerance. Tumour immune tolerance involves the production of immunosuppressive molecules, such as interleukin (IL)-10, transforming growth factor (TGF)-beta and indoleamine-2,3-dioxygenase (IDO) by tumours, which induce a regulatory T cell (T(reg)) response. In this study, we investigated the effect of simvastatin on the production of IL-10, TGF-beta and IDO production and the proliferation of T(regs) using several cancer cell lines, and Lewis lung cancer (3LL) cells-inoculated mouse tumour model. Simvastatin treatment resulted in a decrease in the number of cancer cells (3LL, A549 and NCI-H292). The production of the immune regulatory markers IL-10, TGF-beta in 3LL and NCI-H292 cells increased after treatment with simvastatin. The expression of IDO and forkhead box P3 (FoxP3) transcription factor was also increased in the presence of simvastatin. In a murine 3LL model, there were no significant differences in tumour growth rate between untreated and simvastatin-treated mice groups. Therefore, while simvastatin had an anti-proliferative effect, it also exhibited immune tolerance-promoting properties during tumour development. Thus, due to these opposing actions, simvastatin had no net effect on tumour growth.

Low frequency mutation of the Ephrin receptor A3 gene in hepatocellular carcinoma

EphA3 is a component of the Eph/ephrin tyrosine kinase system, which participates in vasculature development. This receptor/ligand system is associated with various signaling pathways related to cell growth and viability, cytoskeletal organization, cell migration, and anti-apoptosis. Accumulated evidence suggests that aberrant regulation of EphA3 and its genetic alterations are implicated in the development and progression of various cancers. However, despite a high incidence of EphA3 over-expression, no such investigation has been performed in hepatocellular carcinoma. Thus, we investigated genetic alterations of the EphA3 gene in 73 cases of hepatocellular carcinoma by single-strand conformational polymorphism and sequencing. One novel D219V missense mutation was found in the extracellular domain of EphA3, and two genetic alterations in the intracellular sterile-alpha-motif (SAM) domain of EphA3 appeared to be polymorphisms. Although the functional assessments of this mutant are incomplete, it is believed that this novel EphA3 mutation may contribute to the development of hepatocellular carcinoma.

Mutational analysis of JAK1 gene in human hepatocellular carcinoma

The <em>Janus kinase 1</em> (JAK1) gene encodes a cytoplasmic tyrosine kinase that is noncovalently associated with a variety of cytokine receptors and plays a nonredundant role in cell proliferation, survival, and differentiation. The mutated forms of JAK1 often altered the activation of JAK1 and then changed the activation of JAK1/STAT pathways, and this may contribute to cancer development and progression. Thus, to investigate whether genetic mutations of JAK1 gene are associated in hepatocellular carcinoma (HCC) progression, we analyzed genetic alterations of JAK1 gene in 84 human HCCs by single-strand conformational polymorphism (SSCP) and direct sequencing. Of 24 exons of JAK1 gene, 12 exons were previously reported to have mutations, we searched genetic alteration of JAK1 in these exons. Overall, one missense mutation (1.2%) was found. In addition, 12 cases (14%) were found to have single nucleotide polymorphism (14%) in exon 14. Taken together, we found one novel missense mutation of JAK1 gene in hepatocellular carcinomas with some polymorphisms. Although the functional assessment of this novel mutant remains to be completed, JAK1 mutation may contribute to the tumor development in liver cancer.

KEYWORDS

JAK1 gene, hepatocellular carcinoma, mutation.

Synchronous gastric cancer in primary sporadic colorectal cancer patients in Korea

BACKGROUND AND AIMS

Colorectal cancer has been reported to be the malignancy most frequently associated with gastric cancer in Korea. The aim of this study was to define the frequency and clinical characteristics of synchronous gastric cancer detected at preoperative esophagogastroduodenoscopy (EGD) in colorectal cancer patients.

MATERIALS AND METHODS

This prospective study analyzed the EGD results from 1,542 consecutive colorectal cancer patients who underwent surgery from January 2003 to December 2005 at the Center for Colorectal Cancer, National Cancer Center, Korea.

RESULTS

Of the 1,542 cases, 1,155 (74.9%) underwent EGD at our center and 387 underwent EGD at other hospitals within 6 months before surgery. Of the 1,542 cases, synchronous gastric cancers were detected in 31 cases (2.0%). Of these 31 cases, 26 had early gastric cancer (EGC; 83.9%) and 5 had advanced gastric cancer. Ten (38.5%) of the 26 EGC cases were managed using endoscopic mucosal resection. Compared to colorectal cancer patients without synchronous gastric cancer, the group of patients with synchronous gastric cancer was older (65.5+/-9.6 vs 58.4+/-11.3 years, p=0.001) and had a greater proportion of males (77.4 vs 59.4%, p=0.043).

CONCLUSION

This study found that 2% of Korean sporadic colorectal cancer patients had synchronous gastric cancer. A preoperative EGD for colorectal cancer patients is likely to greatly assist in the diagnosis of synchronous gastric cancer at an early stage and the implementation of appropriate minimally invasive treatment.

The local prevalence of COPD by post-bronchodilator GOLD criteria in Korea

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is a disease characterised by not fully reversible airflow limitation. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) committee decided to diagnose COPD using post-bronchodilator spirometry values. We aimed to examine the prevalence and risk factors of COPD in Ansan, an industrialised city of Korea, by using the post-bronchodilator GOLD criteria. We then investigated the implications of brenchodilation on the prevalence of COPD.

DESIGN

A total of 3642 participants in the Korean Health and Genome Study were interviewed about age, income, smoking status and respiratory symptoms and completed pulmonary function tests, including postbronchodilator spirometry.

RESULTS

COPD prevalence by post-bronchodilator spirometry was 3.7% (134/3642), which was significantly different from that estimated using pre-bronchodilator criteria (7.7%, 282/3642). Exclusion of subjects with significant bronchodilator response (BDR) significantly lowered the prevalence of COPD to 3.3% (117/3572), compared with including subjects with post-bronchodilatory residual obstruction with significant BDR. Prevalence was associated with old age, smoking history, male sex and respiratory symptoms.

CONCLUSION

COPD prevalence by post-bronchodilator GOLD criteria was 3.7%, which was much lower than that of pre-bronchodilator criteria. The bronchodilator reversibility test substantially affects estimations of COPD prevalence.

Pre-operative chemo-radiotherapy improves the sphincter preservation rate in patients with rectal cancer located within 3 cm of the anal verge

AIMS

To evaluate whether pre-operative chemo-radiotherapy (CRT) improves the sphincter preservation rate for distal rectal cancers within 3 cm of the anal verge.

METHODS

Between January 2001 and December 2004, 49 patients underwent surgery with or without pre-operative CRT for primary rectal adenocarcinoma within 3 cm of the anal verge. Clinical data were retrospectively reviewed, including stage workups, surgical records and pathology records to determine sphincter preservation rate and the factors influencing sphincter preservation.

RESULTS

Of 49 patients with rectal tumours within 3 cm of the anal verge, 31 underwent pre-operative CRT followed by surgery (CRT group), and 18 underwent surgery alone (non-CRT group). Sphincter preservation was possible in 11 of 31 CRT patients, and only one of 18 non-CRT patients (p=0.036). The factors most influencing sphincter preservation were reduction in tumour size (p=0.005) and downstaging (p=0.001) following pre-operative CRT.

CONCLUSION

We could observe that sphincter preservation was improved in CRT group with statistical significance when compared to non-CRT group in our study patients with rectal cancer within 3 cm of the anal verge.

Topiramate stimulates glucose transport through AMP-activated protein kinase-mediated pathway in L6 skeletal muscle cells

The use of topiramate (TPM) in the treatment of binge-eating disorder, bulimia nervosa, and antipsychotic-induced weight gain has recently increased, however, the exact molecular basis for its effects on body weight reduction and improved glucose homeostasis, is yet to be elucidated. Here we investigated the effect and signaling pathway of TPM on glucose uptake in L6 rat skeletal muscle cells, which account for >70% of glucose disposal in the body. Intriguingly, we found that TPM (10 microM) stimulated the rate of glucose uptake up to twofold increase. And TPM-stimulated glucose transport was inhibited with the overexpression of dominant-negative form of AMP-activated protein kinase (AMPK), an important mediator in glucose transport, implicating that AMPK-mediated pathway is involved. The TPM-stimulated glucose transport was blocked by SB203580, a specific inhibitor of AMPK downstream mediator, p38 mitogen-activated protein kinase (MAPK) protein. LY294002, an inhibitor of phosphatidylinositol (PI) 3-kinase, which is another crucial mediator in independent glucose transport pathway, did not inhibit TPM-stimulated glucose transport. We also found that TPM increased the phosphorylation level of AMPK and p38 MAPK, whereas no effect on the activity of PI 3-kinase of TPM, when assessed by PI 3-kinase assay, was observed. These results together suggest that TPM stimulates glucose transport, not via PI 3-kinase mediated, but via AMPK-mediated pathway in skeletal muscle cells, thereby contributing to the body weight regulation and glucose homeostasis.

[Phototaxis of the green algae: the new class of rhodopsin receptors]

Photomotility behavior in green flagellate algae is mediated by rhodopsin-like receptors, which was initially suggested on the basis of physiological evidence. The cascade of rapid Ca(2+)-dependent electrical responses in the plasma membrane plays a key role in the signal transduction chain during both phototaxis and the photophobic response. The photoreceptor current through the plasma membrane is the earliest detectable event upon photoexcitation of the photoreceptors. Analysis of this current revealed that it consists of at least two components with different characteristics. Genes encoding two archaeal-type rhodopsins (type I rhodopsins) were recently identified in the genome of Chlamydomonas reinhardtii and named (Chlamydomonas Sensory Rhodopsins A and B CSRA and CSRB). The measurements of photoelectric and motor responses in genetic transformants of C. reinhardtii enriched in each of these receptor proteins showed that the two components of the photoreceptor current are mediated by the two rhodopsins, and that both CSRA and CSRB are involved in phototaxis and the photophobic response. The CSRA-mediated current dominates at high light intensities and contributes primarily to the photophobic response. The CSRB-initiated transduction involves an efficient amplification cascade and mediates the highly sensitive phototaxis at low light intensities. CSRA and CSRB expressed heterologously in oocytes of Xenopus laevis act as light-gated proton channels, although it is unclear whether this channel activity plays a functional role in the initiation of motor responses and/or occurs in the native system.

Expression of cyclooxygenase 2, microsomal prostaglandin E synthase 1, and EP receptors is increased in rat oesophageal squamous cell dysplasia and Barrett's metaplasia induced by duodenal contents reflux

BACKGROUND AND AIM

It is known that bile acids can induce mucosal injury, stimulate cell proliferation, and promote tumorigenesis. A large body of genetic and biochemical evidence indicate that the biosynthetic pathway of prostaglandin E2 (PGE2) may play an important role in human and rodent tumours. Therefore, we examined the expression pattern of cyclooxygenase 1 (COX-1), COX-2, and microsomal prostaglandin E synthase 1 (mPGES-1), as well as EP receptor subtypes in rat oesophageal lesions induced by duodenal contents reflux.

METHODS

Oesophagoduodenal anastomosis was performed in rats to induce duodenal contents reflux. We examined histological changes and expression of COX-1, COX-2, mPGES-1, and EP receptor subtypes in the oesophagus by immunohistochemistry and reverse transcription-polymerase chain reaction.

RESULTS

Normal control oesophageal tissues showed COX-1 expression in subepithelial stromal cells, including endothelial cells and muscular cells, and did not reveal expression of COX-2 or mPGES-1. In the case of squamous cell lesions, immunoreactivity of COX-1 was similar to that of normal lesions, and COX-2 was maximally expressed around the vascular papillae of tissues showing dysplasia and surrounding epithelial layer and basal layer. mPGES-1 was highly expressed in stromal cells with COX-2 expression. In the case of Barrett's oesophagus, COX-2 and mPGES-1 were predominantly in subepithelial stromal cells. mRNA levels of COX-2, mPGES-1, EP2, EP3, and EP4 were higher in the experimental groups than in controls.

CONCLUSIONS

We suggest that the biosynthetic pathway of PGE2 may play an important role in oesophageal squamous cell dysplasia and glandular metaplasia induced by duodenal contents reflux.

A phase III randomized trial of 5-fluorouracil, doxorubicin, and mitomycin C versus 5-fluorouracil and mitomycin C versus 5-fluorouracil alone in curatively resected gastric cancer

BACKGROUND

A phase III single-center randomized trial was performed in order to determine whether the addition of mitomycin C (MMC) and/or doxorubicin to 5-fluorouracil (5-FU) as adjuvant chemotherapy could influence survival in patients with curatively resected gastric cancer.

PATIENTS AND METHODS

A total of 416 patients who had undergone curative resection for stage IB-IIIB gastric adenocarcinoma were stratified according to the stage and type of surgery, and then randomized to receive one of the three chemotherapy regimens, 5-FU alone (F) or 5-FU and MMC (FM) or 5-FU, doxorubicin and MMC (FAM) within 5 weeks after surgery.

RESULTS

Of 416 patients registered, 395 (133 in F, 131 in FM and 131 in FAM) were assessable. Median follow-up duration was 91 months. Five-year overall survival rates were 67.2% for F, 67.0% for FM and 66.7% for FAM (P = 0.97). Five-year disease-free survival rates were 62.1% for F, 63.3% for FM and 62.5% for FAM (P = 0.83). Hematological toxicities were more frequent in the FM and FAM groups, whereas stomatitis was more common in the F group.

CONCLUSIONS

Compared with adjuvant 5-FU alone, the addition of MMC and/or doxorubicin to 5-FU did not influence survival in patients with resected gastric cancer.