Abstract 4737: IL-4 and CpG therapy suppresses the outgrowth of tumors by activating tumor-specific Th1-type immune responses

Although interleukin (IL) -4 is often regarded as a type-2 response inducer, recent studies have demonstrated that local IL-4 delivery at the site of vaccination activates local dendritic cells (DCs) and promote type-1 T cell responses. In particular, IL-4 supports DC maturation and enhances IL-12p70 secretion from DCs. Microbial molecules such as lipopolysaccharides, bacteriaderived RNA, and DNA are recognized by host cells through the TLR family, which belongs to the family of pattern-recognition receptors and stimulates immune responses. It has been reported that DNA vaccines and synthetic oligodeoxynucleotides (ODN) containing an unmethylated cytidine-phosphate-guanosine (CpG) motif promote Th1-type immune responses. CpG stimulates DCs through TLR9 and enhances DC maturation, which may improve the therapeutic effects on established tumors. In this study, we evaluated the antitumor effects of IL-4 gene therapy and CpG-ODN treatment in a poorly immunogenic murine cancer model. We used the IL-4 gene-overexpressing murine colorectal cancer MC38 cell line (MC38-IL4). Incubation with MC38-IL4 and CpG-ODN enhanced bone marrow-derived dendritic cell (DC) maturation in vitro. In addition, interferon (IFN)-γ production was significantly increased in naïve splenocytes after they were coincubated with MC38-IL4 and CpG-ODN. When mice bearing MC38 wild-type tumors were inoculated subcutaneously with MC38-IL4 cells and CpG-ODN, the outgrowth of established parental tumors was significantly suppressed compared to those in the MC38-IL4-treated group (IL-4 vs IL-4 + CpG-ODN, p= 0.015). A marked infiltration of CD8+ cells in the established parental tumors of mice treated with MC38-IL4 and CpG-ODN was confirmed by immunohistochemical analyses (MC38-IL4: 2.8 ± 1.9 cells/field vs MC38-IL4 + CpG-ODN: 20.7 ± 15.3 cells/field, p=0.027). Obvious tumor-specific cytolysis was detected when splenocytes of MC38-IL4 + CpG-ODN-treated mice were stimulated by γ-irradiated MC38-IL4 cells and CpG-ODN twice weekly in vitro and used as effector cells in a chromium-release assay (32.2% ± 3.5% for MC38 cells vs 3.2% ± 1.1% for YAC-1 cells; at an effector to target ratio of 40). These results suggest that IL-4 and CpG-ODN treatment promotes potent Th1-type antitumor immune responses. Therefore, the combination of IL-4 gene therapy and CpG-ODN treatment for cancer should be evaluated in clinical trials.

Citation Format: Atsushi Kajiwara, Hiroyoshi Doi, Junichi Eguchi, Shigeaki Ishii, Ayako Sasagawa, Masaki Sakaki, Risa Omori, Eiichi Hayashi, Reiko Makino, Jin Yoshida, Kazumasa Hiroishi, Michio Imawari. IL-4 and CpG therapy suppresses the outgrowth of tumors by activating tumor-specific Th1-type immune responses. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4737. doi:10.1158/1538-7445.AM2013-4737

25-Hydroxyvitamin D3 suppresses hepatitis C virus production

Because the current interferon (IFN)-based treatment for hepatitis C virus (HCV) infection has a therapeutic limitation and side effects, a more efficient therapeutic strategy is desired. Recent studies show that supplementation of vitamin D significantly improves sustained viral response via IFN-based therapy. However, mechanisms and an active molecular form of vitamin D for its anti-HCV effects have not been fully clarified. To address these questions, we infected HuH-7 cells with cell culture-generated HCV in the presence or absence of vitamin D(3) or its metabolites. To our surprise, 25-hydroxyvitamin D(3) [25(OH)D(3) ], but not vitamin D(3) or 1,25-dihydroxyvitamin D(3) , reduced the extra- and intracellular levels of HCV core antigen in a concentration-dependent manner. Single-cycle virus production assay with a CD81-negative cell line reveals that the inhibitory effect of 25(OH)D(3) is at the level of infectious virus assembly but not entry or replication. Long-term 25(OH)D(3) treatment generates a HCV mutant with acquired resistance to 25(OH)D(3) , and this mutation resulting in a N1279Y substitution in the nonstructural region 3 helicase domain is responsible for the resistance.

CONCLUSION

25(OH)D(3) is a novel anti-HCV agent that targets an infectious viral particle assembly step. This finding provides insight into the improved efficacy of anti-HCV treatment via the combination of vitamin D(3) and IFN. Our results also suggest that 25(OH)D(3) , not vitamin D(3) , is a better therapeutic option in patients with hepatic dysfunction and reduced enzymatic activity for generation of 25(OH)D(3) .

Genetic polymorphism in cyclooxygenase-2 promoter affects hepatic inflammation and fibrosis in patients with chronic hepatitis C

Cyclooxygenase (COX)-2 is involved in inflammation, anti-apoptosis and carcinogenesis. The -1195GG genotype of single nucleotide polymorphism (SNP) in COX-2 promoter was associated with low platelet counts in patients with chronic hepatitis C. Polymorphism of patatin-like phospholipase domain-containing protein 3 (PNPLA3) gene (rs738409 C>G) have been reported to be associated with cirrhosis, and the major genotype of SNPs near interleukin (IL)28B are related to viral clearance. The present study was designed to assess the contribution of these SNPs to disease progression in patients with chronic hepatitis C. The study enrolled 220 Japanese patients with chronic hepatitis C. Three SNPs, -1195 COX-2, PNPLA3 and IL28B (rs8099917), were genotyped in order to analyze their association with hepatic fibrosis and inflammation. The -1195GG genotype in COX-2 was associated with advanced fibrosis and higher levels of inflammation in the liver tissues. The major genotype of IL28B was also associated with advanced fibrosis, but the polymorphism of PNPLA3 was neither associated with fibrosis nor inflammation. Multivariate analysis showed that -1195GG in COX-2 is an independent factor associated with advanced fibrosis, while the major genotype of IL28B and HCV genotype 2 were other independent factors. In conclusion, the -1195GG genotype in COX-2 is a genetic marker for liver disease progression, while the PNPLA3 genotypes are not associated with disease progression in Japanese patients with chronic hepatitis C.

Genetic polymorphism in cyclooxygenase-2 promoter affects hepatic inflammation and fibrosis in patients with chronic hepatitis C

Cyclooxygenase (COX)-2 is involved in inflammation, anti-apoptosis and carcinogenesis. The -1195GG genotype of single nucleotide polymorphism (SNP) in COX-2 promoter was associated with low platelet counts in patients with chronic hepatitis C. Polymorphism of patatin-like phospholipase domain-containing protein 3 (PNPLA3) gene (rs738409 C>G) have been reported to be associated with cirrhosis, and the major genotype of SNPs near interleukin (IL)28B are related to viral clearance. The present study was designed to assess the contribution of these SNPs to disease progression in patients with chronic hepatitis C. The study enrolled 220 Japanese patients with chronic hepatitis C. Three SNPs, -1195 COX-2, PNPLA3 and IL28B (rs8099917), were genotyped in order to analyze their association with hepatic fibrosis and inflammation. The -1195GG genotype in COX-2 was associated with advanced fibrosis and higher levels of inflammation in the liver tissues. The major genotype of IL28B was also associated with advanced fibrosis, but the polymorphism of PNPLA3 was neither associated with fibrosis nor inflammation. Multivariate analysis showed that -1195GG in COX-2 is an independent factor associated with advanced fibrosis, while the major genotype of IL28B and HCV genotype 2 were other independent factors. In conclusion, the -1195GG genotype in COX-2 is a genetic marker for liver disease progression, while the PNPLA3 genotypes are not associated with disease progression in Japanese patients with chronic hepatitis C.

Effects of interferon-α-transduced tumor cell vaccines and blockade of programmed cell death-1 on the growth of established tumors

Interferon-alpha (IFN-α) has strong antitumor effects, and IFN-α gene therapy has been used clinically against some cancers. In this study, we evaluated the efficacy of the combination of IFN-α-transduced tumor cell vaccines and programmed cell death 1 (PD-1) blockade, and investigated the mechanisms of the antitumor effects of the combined therapy. A poorly immunogenic murine colorectal cancer cell line, MC38, was transduced to overexpress IFN-α. In a therapeutic model, parental tumor-bearing mice were inoculated with MC38-IFNα cells and an anti-PD-1 antagonistic antibody. Analyses of immunohistochemistry and tumor-specific lysis were performed. The outgrowth of the established tumors was significantly reduced in mice treated with the combination of IFN-α and anti-PD-1. Immunohistochemical analyses of the therapeutic model showed marked infiltration of CD4(+) cells and CD8(+) cells in the established MC38 tumors of mice treated with both IFN-α and anti-PD-1. Significant tumor-specific cytolysis was detected when splenocytes of mice that were treated with both IFN-α and anti-PD-1 were used as effector cells. These results suggest that blockade of the PD-1 PD-ligand enhanced the Th1-type antitumor immune responses induced by IFN-α. The combination of IFN-α gene-transduced tumor cell vaccines and PD-1 blockade may be a possible candidate for a cancer vaccine for clinical trials.

Abstract 524: Cytokine therapy by allogenic IFN-alpha-expressing murine colorectal cancer cells suppresses outgrowth of established tumors in a murine hepatocellular carcinoma model

Although several effective therapies for hepatocellular carcinoma (HCC) have been developed, many patients with both advanced cirrhosis and HCC are not able to receive those treatments because of their poor liver function. Thus, it is needed to establish a new effective therapy that has lesser side effects for those patients. We previously reported that immunotherapy by interferon-alpha (IFNa) and dendritic cells effectively suppressed outgrowth of established tumors and showed preventive effects in the murine colorectal cancer, MC38 cell model. We also revealed that tumor-specific cytotoxic T cell responses were important for these anti-tumor effects. In this study, we investigated the antitumor effect of allogenic cytokine (IFNa and IL-4)- expressing MC38 cells in the murine hepatocellular carcinoma, BNL model. There were no differences in cell growth between BNL cells and BNL cells co-incubated with cytokine-expressing MC38 cells in vitro. Balb/c mice were injected with 5x105 of BNL cells on their flank. Once BNL tumors were established, these mice received therapeutic injection of cytokine-expressing MC38 cells (2.5x105/mouse or 5x105/mouse) and tumor size was measured twice weekly. While tumor growth of the mice injected with MC38-IL4 was not suppressed (control; 421.0±146.9mm2, MC38-IL4 (5x105); 351.3±126.1mm2, p=0.33), injection of MC38-IFNa cells significantly suppressed the tumor growth by dose-dependent manner (MC38-IFNa: 5x105 cells; 183.5±46.2mm2, p=0.02). When we injected mice with both IFNa cells and IL-4 cells, any additive anti-tumor effects were not observed (mice injected both modified MC38: 5x105 cells each; 182±44.6 mm2, p=0.01). A BNL-specific cytolysis was detected when splenocytes of mice injected with MC38-IFNa were used as effector cells in a chromium-release assay. Furthermore, immunohistocemistrical analysis revealed that CD4+ T cells, CD8+ T cells and especially Gr-1+ cells infiltrated established BNL tumors of mice injected with MC38-IFNa. Our results suggest that the immunotherapy with allogenic IFNa-expressing cells has potent antitumor effects, and that it would be applicable for treatment to advanced HCC patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 524. doi:1538-7445.AM2012-524

Abstract 4386: Effects of interferon-α-transduced tumor cell vaccines and blockade of programmed cell death 1 on the growth of established tumors

Progress in treatments for cancer has improved the prognosis of patients with colorectal cancer. However, there is a strong need for the development of a new intervention therapy that suppresses the occurrence or recurrence effectively with fewer side effects. Immunotherapy may be such a treatment and gene therapy using tumor cells that are genetically modified to produce cytokines has been studied in several therapeutic models. We have previously reported that the interferon (IFN)-α gene-transduced tumor-based vaccination therapy suppresses the outgrowth of established tumors. Although the suppressive effects on established tumors were observed, we did not see reductions in the size of all of the parental tumors. Therefore, further improvements in the treatment are needed before clinical application, we focused on programmed cell death 1 (PD-1), which has been identified as a marker of exhausted T cells. In this study, we evaluated the efficacy of the combination of IFN-γ-transduced tumor cell vaccines and PD-1 blockade, and investigated the mechanisms of the antitumor effects of the combined therapy. A poorly immunogenic murine colorectal cancer cell line, MC38, was transduced to overexpress IFN-γ (MC38-IFNα). In a therapeutic model, parental tumor-bearing mice were inoculated with MC38-IFNα cells and an anti-PD-1 antagonistic antibody. Significant suppression of outgrowth of the established tumors was observed in the IFN-γ and anti-PD-1 combination treatment group (IFN+ anti-PD-1, 174.17 ± 35.54 mm2 vs control, 328.67 ± 26.36 mm2 on day 28, P = 0.0114 vs controls). Immunohistochemical analyses showed marked infiltration of CD4+ cells as well as CD8+ cells in the established tumors of mice treated with both IFN-γ and anti-PD-1. To investigate induction of tumor-specific immune responses, we stimulated splenocytes of IFN-γ or/and anti-PD-1 treated mice twice weekly by DCs in vitro. Significant tumor-specific cytolysis was detected when splenocytes of mice treated with both IFN-γ and anti-PD-1 were used as effector cells (58.1% ± 6.7% for MC38 and 14.1% ± 1.7% for YAC-1, effector:target = 20, P < 0.001). Our findings suggest that blockade of the PD-1 PD-ligand enhanced the Th1-type antitumor immune responses induced by IFN-γ. The combination of IFN-γ gene-transduced tumor cell vaccines and PD-1 blockade may be a possible candidate for a cancer vaccine for clinical trials.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4386. doi:1538-7445.AM2012-4386

Lymphotropic hepatitis C virus has an interferon-resistant phenotype

Hepatitis C virus (HCV) infects and associates with B cells, leading to abnormal B-cell activation and development of lymphoproliferative and autoimmune disorders. This immune perturbation may in turn be associated with the resistance of HCV against the host immune system. The objective of this study was to analyse the effects of HCV infection of B cells on the efficacy of interferon (IFN)-based therapy. The study enrolled 102 patients with chronic hepatitis C who were treated with pegylated IFN plus ribavirin. HCV RNA titres in B cells were compared in patients with rapid viral responder (RVR) vs non-RVR, sustained viral responder (SVR) vs non-SVR and null viral responder (NVR) vs VR. The levels of HCV RNA in B cells were significantly higher in non-RVR, non-SVR and NVR groups. Association between the therapy outcome and the positive B-cell HCV RNA was also investigated in relation to other known viral and host factors. Multivariable analyses showed that the positive B-cell HCV RNA and the minor single-nucleotide polymorphism near the IL28B gene (rs8099917) were independent factors associated with NVR in patients infected with HCV genotype 1. When these two factors were combined, the sensitivity, specificity, positive and negative predictive values for NVR were 92.3%, 98.2%, 92.3% and 98.2%, respectively. Genotype 1 and the presence of one or no mutations in the IFN-sensitivity determining region were associated with higher levels of B-cell HCV RNA. B-cell-tropic HCV appears to have an IFN-resistant phenotype. B-cell HCV RNA positivity is a predictive factor for resistance to IFN-based therapy.

Interleukin-4 and CpG oligonucleotide therapy suppresses the outgrowth of tumors by activating tumor-specific Th1-type immune responses

Because IL-4 and CpG oligodeoxynucleotides (CpG-ODNs) are immune stimulants, we evaluated the antitumor effects of IL-4 gene therapy and CpG-ODN treatment in a poorly immunogenic murine cancer model. We used a murine colorectal cancer MC38 cell line overexpressing the IL-4 gene (MC38-IL4). Incubation with MC38-IL4 and CpG-ODN enhanced bone marrow-derived dendritic cell (DC) maturation in vitro. In addition, interferon (IFN)-γ production was significantly increased in naïve splenocytes after they were coincubated with MC38-IL4 and CpG-ODN. When mice bearing MC38 wild-type tumors were inoculated subcutaneously with MC38-IL4 cells and CpG-ODN, the outgrowth of established parental tumors was significantly suppressed compared to those in the MC38-IL4-treated group (IL-4 vs. IL-4 + CpG-ODN, p=0.015). A marked infiltration of CD8+ cells in the established parental tumors of mice treated with MC38-IL4 and CpG-ODN was confirmed by immunohistochemical analyses (MC38-IL4, 2.8 ± 1.9 cells/field vs. MC38-IL4 + CpG-ODN, 20.7 ± 15.3 cells/field, p=0.027). Significant tumor-specific cytolysis was detected when splenocytes of MC38-IL4 + CpG-ODN-treated mice were stimulated by γ-irradiated MC38-IL4 cells and CpG-ODN twice weekly in vitro and used as effector cells in a chromium-release assay (32.2 ± 3.5% for MC38 cells vs. 3.2 ± 1.1% for YAC-1 cells; at an effector to target ratio of 40). These results suggest that IL-4 and CpG-ODN treatment promotes potent Th1-type antitumor immune responses. Therefore, the combination of IL-4 gene therapy and CpG-ODN treatment for cancer should be evaluated in clinical trials.

Anti-hypoalbuminemic effect of branched-chain amino acid granules in patients with liver cirrhosis is independent of dietary energy and protein intake

AIM

  A multicenter prospective intervention study was conducted in 204 patients with uncompensated liver cirrhosis to explore the influence of dietary intake and patient clinical characteristics on improvement of hypoalbuminemia at weeks 12 and 24 of treatment with branched-chain amino acid (BCAA) granules.

METHODS

  The primary endpoint set in this study was improvement of hypoalbuminemia in patients with liver cirrhosis. The dietary energy and protein intake per day were estimated based on the results of a survey on diet during a 3-day period preceding the start of the study.

RESULTS

  As for the primary endpoint, the mean serum albumin level increased significantly at weeks 12 and 24 of BCAA treatment, compared with the baseline level. The mean Child-Pugh score decreased significantly at weeks 12 and 24 of treatment as compared to the mean baseline score. There was a significant increase in the serum albumin level following treatment with BCAA granules regardless of energy intake and of protein intake. The incidence of ascites and edema significantly decreased in the overall patient population both at weeks 12 and 24 of treatment, compared with the baseline incidence. A subgroup analysis conducted in patients stratified according to changes in the serum albumin level at week 12 of treatment as against baseline showed that the incidence of ascites/edema was significantly reduced not only in the increased albumin group but in the unchanged albumin group.

CONCLUSION

  The present data suggest that the anti-hypoalbuminemic effect of BCAA treatment in patients with liver cirrhosis is independent of dietary intake.

Cancer preventive effect of pegylated interferon α-2b plus ribavirin in a real-life clinical setting in Japan: PERFECT interim analysis

AIM

  This study was conducted to clarify the incidence of hepatocellular carcinoma (HCC) and the factors contributing to its occurrence by following chronic hepatitis C patients who received pegylated interferon (PEG-IFN) α-2b plus ribavirin (RBV) combination therapy.

METHODS

  Patients who received PEG-IFN α-2b and RBV combination therapy with no history of HCC or HCC within 3 months after the start of treatment were observed for the onset of HCC at 67 centers.

RESULTS

  Sustained virological response (SVR) was observed in 999 (53.5%) of 1865 patients eligible for analysis. During the observation period (median duration: 4 years and 3 months), HCC developed in 59 patients (3.1%). A significant difference was observed in the 5-year cumulative incidence of HCC between SVR and non-SVR patients (1.1% vs. 7.1%). Factors contributing to HCC selected in multivariate analysis were therapeutic efficacy, sex, age, alanine aminotransferase (ALT) level at 24 weeks after the end of treatment, and platelet count. Non-SVR patients with ALT improvement after the end of treatment had a significantly lower 5-year cumulative incidence of HCC than those without (3.4% vs. 11.0%). HCC developed in 10 patients who achieved SVR, and multivariate analysis indicated that ALT level at 24 weeks after the end of treatment was the only significant factor contributing to HCC.

CONCLUSION

  Several known risk factors for HCC contributed to HCC in patients who received PEG-IFN α-2b and RBV combination therapy, and ALT abnormality after the end of treatment contributes to the onset of HCC in both non-SVR and SVR patients.

Clarification of interspousal hepatitis C virus infection in acute hepatitis C patients by molecular evolutionary analyses: Consideration on sexual and non-sexual transmission between spouses

AIM

  Previous studies evaluating the possibilities of interspousal sexual transmission of hepatitis C virus (HCV) have yielded many conflicting results. The aim of this study was to clarify the source of HCV infection in acute hepatitis C patients using phylogenetic analyses of nucleotide sequences of HCV E1 region.

METHODS

  Four acute hepatitis C patients were hospitalized in 2002-2007. The diagnosis was based on medical records, laboratory tests including HCV markers, and ultrasonographic examination of the liver. In each spouse of four patients, serum HCV antibody was assayed. In the subjects whose serum HCV antibody was positive, additional tests on HCV viral load and genotype were carried out. Then phylogenetic analyses of nucleotide sequences of partial HCV E1 region (440 nucleotides) of the patients and their spouses were performed.

RESULTS

  Hepatitis C virus antibody changed from negative to positive in the course of hospitalization and HCV RNA could be detected in every patient. Therefore they were diagnosed as acute hepatitis caused by HCV infection. In every spouse of four patients, HCV antibody and HCV RNA were positive. Three of four couples had the identical genotype and homogeneity of nucleotide sequences of HCV E1 region in three couples ranged from 97.9% to 100%. The results of phylogenic analyses suggested that interspousal HCV infection occurred in the three couples.

CONCLUSION

  In conclusion, interspousal infection might be one of the important sources of acute HCV infection in Japan. The usefulness of phylogenetic analysis of nucleotide sequences of HCV E1 region for clarifying interspousal HCV infection was validated.

Clinicopathological and molecular features of colorectal serrated neoplasias with different mucosal crypt patterns

OBJECTIVES

Endoscopic examination shows that serrated neoplasias (SNs), such as serrated adenomas and sessile serrated adenomas, exhibit different mucosal crypt patterns. However, it remains unclear whether advanced serrated polyps with different mucosal crypt patterns have different clinicopathological or molecular features.

METHODS

We classified the mucosal crypt patterns of 86 SNs into three types (hyperplastic, adenomatous, and mixed pattern) and evaluated their clinicopathological and molecular features.

RESULTS

We found significant differences in the proliferative activity status between SNs with mixed/adenomatous patterns and those with the hyperplastic patterns. SNs with the hyperplastic pattern were frequently located in the proximal colon and had a macroscopically superficial appearance, whereas SNs with the adenomatous pattern were often located in the distal colon and had a protruding appearance. Furthermore, a significant difference was observed in the frequency of the CpG island methylator phenotype (CIMP), involving the methylation of two or more CIMP-related genes (MINT1, MINT2, MINT31, p16, and MLH1), between SNs with the hyperplastic pattern and those with the mixed/adenomatous patterns (18/32 (56%) vs. 8/28 (29%) or 7/26 (27%); P=0.0309 or P=0.0249, respectively). Moreover, the prevalence of KRAS mutations was significantly higher in SNs with the adenomatous pattern than in those with the hyperplastic pattern (7/26 (27%) vs. 1/32 (3%); P=0.0173). In comparison with other patterns, the mixed pattern was detected more frequently in mixed serrated polyps (MSPs), which contain separate histological components. Some MSPs exhibited concordant molecular alterations among the different histological components.

CONCLUSIONS

The clinicopathological and molecular features of SNs correlated strongly with their mucosal crypt patterns, which were observed using chromoendoscopy.

IFN-γ production by lung NK cells is critical for the natural resistance to pulmonary metastasis of B16 melanoma in mice

NK cells are effector lymphocytes playing a critical role in the natural resistance against tumors. However, the precise mechanisms underlying NK cell-mediated natural resistance against tumor metastasis are still unrevealed. B16 cells, mouse melanoma cells, were resistant to freshly isolated NK cell-mediated killing; nevertheless, NK cells were critical for natural resistance against experimental lung metastasis of B16 cells. We found that lung metastasis was increased significantly in IFN-γ(-/-) mice but not pfp(-/-), IFN-αR(-/-), or IL-12/IL-18(-/-) mice. Interestingly, freshly isolated lung NK cells, but not spleen or liver NK cells, displayed augmented IFN-γ production after B16 inoculation. Adoptive transfer of pfp(-/-) NK cells, but not IFN-γ(-/-) NK cells, significantly decreased B16 lung metastasis in IFN-γ(-/-) and pfp/IFN-γ(-/-)mice. Lung metastases of IFN-γRDN B16 was also increased in NK cell-depleted or IFN-γ(-/-) mice, suggesting that the IFN-γ response of host cells was required in the NK cell and IFN-γ-mediated antimetastatic effect. Our results demonstrate that IFN-γ production from lung resident NK cells is a key response in the natural resistance to the experimental lung metastasis of NK cell-resistant tumor cells.

Analysis of the risk factors for myelosuppression after chemoradiotherapy involving 5-fluorouracil and platinum for patients with esophageal cancer

BACKGROUND/AIMS

Myelosuppression is a serious adverse effect of chemotherapy, but its risk factors remain largely unknown. The present study retrospectively evaluated clinical data obtained before therapy to clarify the risk factors for myelosuppression after chemoradiotherapy in patients with esophageal cancer.

METHODOLOGY

One-hundred-and-eight patients who received 5-fluorouracil combined with platinum and 60Gy radiation for esophageal cancer were analyzed. The endpoint of this survey was the occurrence of grade 3 or higher myelosuppression (neutropenia, anemia or thrombocytopenia). Risk factors significantly related to myelosuppression were extracted using logistic regression analysis.

RESULTS

Grade 3 or higher neutropenia, anemia or thrombocytopenia occurred in 32.4%, 13.0% and 10.2% of the patients, respectively. According to the multivariate analysis, the risk factors included hoarseness, platelet count and the type of platinum for neutropenia; performance status and hemoglobin for anemia; and performance status, platelet count and serum creatinine concentration for thrombocytopenia (p<0.05).

CONCLUSIONS

It was found that performance status, bone marrow function and hoarseness are the most important factors for chemoradiotherapy-induced myelosuppression in esophageal cancer. The prediction of myelosuppression is expected to be useful for the determination of the appropriate therapeutic approach for each patient by a physician.

Sporadic fundic gland polyp-related adenomas occurred in non-atrophic gastric mucosa without helicobacter pylori infection

We report three cases of adenoma associated with sporadic fundic gland polyp (FGP) in the non-atrophic fundic gland mucosa without Helicobacter pylori (HP) infection, which was verified with both serological and histopathological examinations. Gastric tubular adenoma (flat adenoma) is common and focal cancers occurring in the hyperplastic polyp of foveolar cell type are also sometimes experienced. However, adenomas occurring in sporadic FGP are valuable, as they are very rare, in upper gastrointestinal endoscopy. Whether or not these adenoma lesions of three sporadic FGP cases may become the background of protruded gastric cancers without HP infection remains unclear. Therefore, we emphasize the importance of histological examination on fundic gland polyps that are > 5 mm in size to accumulate new similar cases. Follow-up studies of these lesions are also needed to evaluate their outcomes.

Right colon cancer presenting as hemorrhagic shock

A 67-year-old man visited our hospital with a history of continuous hematochezia leading to hemorrhagic shock. An abdominal computed tomography scan revealed a large mass in the ascending colon invading the duodenum and pancreatic head as well as extravasation of blood from the gastroduodenal artery (GDA) into the colon. Colonoscopy revealed an irregular ulcerative lesion and stenosis in the ascending colon. Therefore, right hemicolectomy combined with pylorus-preserving pancreaticoduodenectomy was performed. Histologically, the tumor was classified as a moderately differentiated adenocarcinoma. Moreover, cancer cells were mainly located in the colon but had also invaded the duodenum and pancreas and involved the GDA. Immunohistochemically, the tumor cells were positive for cytokeratin (CK)20 and carcinoembryonic antigen (CEA) but not for CK7 and carbohydrate antigen (CA)19-9. The patient died 23 d after the surgery because he had another episode of arterial bleeding from the anastomosis site. Although En bloc resection of the tumor with pancreaticoduodenectomy and colectomy performed for locally advanced colon cancer can ensure long-term survival, patients undergoing these procedures should be carefully monitored, particularly when the tumor involves the main artery.

TS gene tandem repeats in esophageal cancer patients receiving chemoradiotherapy

5-Fluorouracil (5-FU) interferes with tumor-cell proliferation by inhibiting thymidylate synthase (TS). We examined the relationship between tandem repeat (TR) variations in the TS gene and survival following concurrent chemoradiotherapy in patients with esophageal squamous cell carcinoma (ESCC). TS-TR variations were analyzed in 57 stage II-IV ESCC patients undergoing chemoradiotherapy combined with 5-FU and cisplatinum (CDDP), and in 106 controls. Pretreatment non-neoplastic biopsy specimens from ESCC patients and lymphocytes from controls were used for analysis. Variations were identified by the size of DNA fragments amplified by polymerase chain reaction. Two to five TRs were found in Japanese individuals. TR3 homozygotes were predominant in 74% of ESCC patients and 61% of controls. Three-year survival rates were significantly longer in patients with TR2/2 or TR2/3 genotypes (38%) than in patients with TR3/3, 3/4, or 3/5 genotypes (9%; p=0.011). In the Cox proportional hazard model, the TR2/2 or TR2/3 genotypes were the only independent predictor for survival (Hazard ratio, 2.647; 95% confidence interval, 1.271-5.513). The TS-TR variations exert an important influence on survival following chemoradiotherapy in ESCC patients.

Cyclooxygenase-2 gene promoter polymorphisms affect susceptibility to hepatitis C virus infection and disease progression

AIM

  Because polymorphisms of cyclooxygenase-2 (COX-2) and osteopontin (OPN) promoter regions and a promoter/enhancer region of forkhead box protein 3 (FOXP3) gene are known to affect immune responses, we examined whether these polymorphisms can influence susceptibility to hepatitis C virus (HCV) infection and progression of liver disease.

METHODS

  Peripheral blood samples were obtained from 104 Japanese patients with chronic HCV infection and 74 healthy Japanese donors. Polymerase chain reaction single-stranded conformational polymorphism analysis of genomic DNA was performed to determine the polymorphisms.

RESULTS

  The risk of persistent HCV infection was decreased in subjects with -1195GG genotype of the COX-2 promoter region. However, in patients with chronic HCV infection, the -1195GG genotype was associated with advanced-stage liver disease. A luciferase reporter assay performed to analyze the effect of single nucleotide polymorphisms (SNP) (-1195A or -1195G) in COX-2 gene on transcriptional activity using the HepG2, Huh7 and HeLa cell lines indicated that the -1195G genotype showed higher transcriptional activity than the -1195A genotype. SNP of OPN and FOXP3 did not differ between patients with chronic HCV infection and controls. However, the -443TT genotype of the OPN promoter region was associated with increased inflammatory activity of the liver.

CONCLUSION

  These results suggest that the -1195GG genotype of the COX-2 promoter region protects against HCV infection in the Japanese. However, once chronic infection is established, the -443TT genotype of the OPN promoter region and the -1195GG genotype of the COX-2 promoter are thought to promote inflammation and contribute to the progression of liver disease.