Seong-Taek Oh

SOX4 overexpression regulates the p53-mediated apoptosis in hepatocellular carcinoma: clinical implication and functional analysis in vitro

BACKGROUND AND AIMS The underlying molecular mechanisms of hepatocellular carcinoma (HCC) remain poorly understood due to its complex development process. The human T cell-specific transcription factor sex-determining region Y-related high-mobility group (HMG) box 4 (SOX4) has been linked to development and tumorigenesis. In this study, we characterized the roles of SOX4 in regulation of the p53 transcription activity and evaluated the expression patterns and prognostic value of the transcription factor SOX4 in HCC. METHODS The expression levels of human SOX4 were examined in HCC samples obtained from 58 patients having curative partial hepatectomy. The interaction and effects of SOX4 on the p53 pathway were assessed in HCC cell lines. Luciferase reporter assay to examine p53-mediated transcription of target genes was performed. The association of SOX4 expression level with tumor recurrence and overall survival was evaluated. RESULTS We showed that the HMG box domain of SOX4 interacted with p53, resulting in the inhibition of p53-mediated transcription by the Bax promoter. More importantly, SOX4 overexpression led to a significant repression of p53-induced Bax expression and subsequent repression of p53-mediated apoptosis induced by gamma-irradiation. In clinicopathological analysis, nuclear overexpression of SOX4 was observed in 37 out of 58 (63.8%) HCC samples, and this correlated with diminished risk of recurrence (P = 0.014) and improved overall survival time (P = 0.045) in HCC patients. CONCLUSION These results suggest that SOX4 contributes to hepatocarcinogenesis by inhibiting p53-mediated apoptosis and that its overexpression might be a useful prognostic marker for survival after surgical resection.

Single incision vs conventional laparoscopic anterior resection for sigmoid colon cancer: a case-matched study

BACKGROUND The purpose of the study was to evaluate the safety and effects of single-incision laparoscopic anterior resection (SILAR) for sigmoid colon cancer by comparing it with conventional laparoscopic anterior resection (CLAR). METHODS Twenty-four patients who underwent SILAR between April 2010 and July 2011 were case matched 1:2 with patients who underwent CLAR, with respect to age, sex, body mass index, tumor location, and history of abdominal surgery. RESULTS Two patients in the SILAR group and 1 patient in the CLAR group experienced anastomotic leakage. The operative time was longer in the SILAR group than in the CLAR group (251 ± 50 vs 237 ± 49 minutes; P = .253). The number of harvested lymph nodes (19.6 ± 10.7 vs 20.8 ± 7.7; P = .630) was not different. The postoperative hospital stay was shorter in the SILAR group (7.1 ± 3.4 days) than in the CLAR group (8.1 ± 3.5 days) (P = .234). CONCLUSIONS On the basis of the early outcomes, we conclude that SILAR is feasible and safe. Moreover, the adequate lymph node harvest and free margins support the use of this procedure.

The nutritional risk is a independent factor for postoperative morbidity in surgery for colorectal cancer

Purpose The authors evaluate the prevalence of malnutrition and its effect on the postoperative morbidity of patients after surgery for colorectal cancer. Methods Three hundred fifty-two patients were enrolled prospectively. Nutritional risk screening 2002 (NRS 2002) score was calculated through interview with patient on admission. Clinical characteristics, tumor status and surgical procedure were recorded. Results The prevalence of patients at nutritional risk was 28.1 per cent according to the NRS 2002. The rate of postoperative complication was 27%. There was a significant difference in postoperative complication rates between patients at nutritional risk and those not at risk (37.4% vs. 22.9%, P = 0.006). Nutritional risk was identified as an independent predictor of postoperative complications (odds ratio, 3.05; P = 0.045). Nutritional risk increased the rate of anastomotic leakage (P = 0.027) and wound infection (P = 0.01). Conclusion NRS may be a prognostic factor for postoperative complication after surgery for colorectal cancer. A large scaled prospective study is needed to confirm whether supplementing nutritional deficits reduces postoperative complication rates.

Wnt3a expression is associated with MMP-9 expression in primary tumor and metastatic site in recurrent or stage IV colorectal cancer

BackgroundThe wnt/β-catenin signaling pathway is known to affect in cancer oncogenesis and progression by interacting with the tumor microenvironment. However, the roles of wnt3a and wnt5a in colorectal cancer (CRC) have not been thoroughly studied. In the present study, we investigated the expression of wnt protein and the concordance rate in primary tumor and metastatic sites in CRC. To determine the relationship of wnt proteins with invasion related protein, we also analyzed the association between wnt protein expression and the expression of matrix metalloproteinase-9 (MMP-9) and vascular endothelial growth factor receptor-2 (VEGFR-2).MethodsTumor tissue was obtained from eighty-three paraffin- embedded blocks which were using resected tissue from both the primary tumor and metastatic sites for each patient. We performed immunohistochemical staining for wnt3a, wnt5a, β-catenin, MMP-9 and VEGFR-2.ResultsWnt3a, wnt5a, β-catenin, and MMP-9 expression was high; the proteins were found in over 50% of the primary tumors, but the prevalence was lower in tissue from metastatic sites. The concordance rates between the primary tumor and metastatic site were 76.2% for wnt5a and 79.4% for wnt3a and β-catenin, but VEGFR-2 was expressed in 67.4% of the metastatic sites even when not found in the primary tumor. Wnt3a expression in primary tumors was significantly associated with lymph node involvement (p = 0.038) and MMP-9 expression in the primary tumor (p = 0.0387), mesenchyme adjacent to tumor (p = 0.022) and metastatic site (p = 0.004). There was no other relationship in the expression of these proteins. Vascular invasion in primary tumor tissue may be a potential prognostic marker for liver metastasis, but no significant association was observed among the wnt protein, MMP-9, and VEGFR-2 for peritoneal seeding. In survival analysis, β-catenin expression was significantly correlated with overall survival (p = 0.05).ConclusionsWnt3a and wnt5a expression had a concordance rate higher than 60% with a high concordance rate between the primary tumor and metastatic site. Wnt3a expression is associated with the expression of MMP-9 in primary tumor tissue adjacent mesenchymal tissue, and at the metastatic site. As a prognostic marker, only β-catenin expression showed significant relation with survival outcome.

Co‐administration of carcinoembryonic antigen and HIV TAT fusion protein with CpG‐oligodeoxynucleotide induces potent antitumor immunity

Although dendritic cells (DC) have been well demonstrated as a strong cellular adjuvant for a tumor vaccine, there are several limitations for clinical application. A protein‐based vaccine using a potent adjuvant is an appealing approach for tumor antigen‐specific immunotherapy because of their simplicity, safety, efficacy and capacity for repeated administration. CpG‐oligodeoxynucleotides (ODN) have been used as adjuvants to stimulate innate and adaptive immune responses for cancer treatment. The authors evaluated the adjuvant effects of CpG‐ODN in a vaccine incorporating recombinant fusion protein of the HIV TAT PTD domain and carcinoembryonic antigen (TAT‐CEA). Mice vaccinated with TAT‐CEA and CpG‐ODN (TAT‐CEA + CpG) showed enhanced CEA‐specific immunity, including cytotoxic T‐lymphocytes (CTL) activity and interferon (IFN)‐γ secreting T cells compared with CEA and CpG‐ODN (CEA + CpG) or TAT‐CEA vaccination alone. Vaccination with TAT‐CEA + CpG elicited Th1‐based responses, as indicated by the higher ratio of immunoglobulin (Ig)G2a antibody/IgG1 antibodies specific for CEA. The survival rate was significantly increased after vaccination with TAT‐CEA + CpG in a tumor model using MC38/CEA2. Furthermore, the TAT‐CEA ± CpG vaccine groups showed similar antitumor immunity to the CEA peptide‐pulsed DC (CEA peptide/DC) vaccine groups. These data suggest that coadministration of TAT fusion protein with CpG‐ODN may serve as a potential formulation for enhancing antitumor activity. (Cancer Sci 2008; 99: 1034–1039)

Comparison of bolus transit patterns identified by esophageal impedance to barium esophagram in patients with dysphagia

Bolus transit through the esophagus has not been validated by videoesophagram in patients with dysphagia and changes in impedance with abnormal barium transit have not been described in those patients. The aim of this study was to compare esophageal impedance findings with barium esophagram measurements in patients with dysphagia. The consecutive patients with dysphagia underwent conventional multichannel esophageal impedance manometry, after which a barium videoesophagram was performed simultaneously with multichannel esophageal impedance manometry using a mean of three swallows of barium. Esophageal emptying patterns shown in the esophagogram were classified by the degree of intraesophageal stasis and presence of intraesophageal reflux. Bolus transit patterns in impedance were classified as complete and incomplete transit. Sixteen patients (M : F = 8 : 8, mean age, 47 years) were enrolled. Their manometric diagnosis were normal (n= 6), ineffective esophageal motility (n= 1), diffuse esophageal spasm (DES; n= 2), and achalasia (n= 7). Sixty-three swallows were analyzed. According to impedance analysis, 21/22 swallows with normal barium emptying showed complete transit (96%) and 31/32 swallows with severe stasis showed incomplete transit (97%). Nine swallows with mild stasis showed either complete or incomplete transit patterns in impedance. Swallows with mild barium stasis and complete transit in impedance were observed in patients who had received treatment (two patients with achalasia with history of esophageal balloonplasty and a patient with DES after nifedipine administration). Impedance reflected severe stasis with retrograde barium movement and described typical bolus transit patterns in patients with achalasia and DES. In conclusion, impedance-barium esophagram concordance is high for swallows with normal esophageal emptying and for severe barium stasis in patients with dysphagia.

Dendritic cell vaccine in addition to FOLFIRI regimen improve antitumor effects through the inhibition of immunosuppressive cells in murine colorectal cancer model.

Although chemotherapy is still one of the best treatments for most cancers, immunotherapies such as dendritic cell (DC) vaccines have emerged as an alternative protocol for destroying residual tumors. In this study, we investigated antitumor effects of the combined therapy using DC vaccine and irinotecan plus infusional 5-fluorouracil and leucovorin (FOLFIRI) which have been clinically used for the treatment of colorectal cancer. A maximum tolerated dose of FOLFIRI was preliminarily determined for MC38/CEA2 colorectal cancer model. Vaccination with DC expressing carcinoembryonic antigen (CEA) enhanced antitumor effect after FOLFIRI treatment. The combined therapy also increased CEA-specific Th1 and cytotoxic T-cell responses. Interestingly, although FOLFIRI treatment rather showed a rebound in the number of myeloid-derived suppressor cells (MDSC) and regulatory T-cells (Treg) after 14 days, additional DC vaccine could inhibit the rebound of these immunosuppressive cells. Furthermore, mice cured by the combined therapy showed antigen-specific T-cell responses and resistance against challenge of MC38/CEA2 compared with mice cured with FOLFIRI. These results demonstrated that DC vaccine in addition to FOLFIRI regimen could improve antitumor effects through the inhibition of immunosuppressive tumor environments in murine colorectal cancer model, and may provide knowledge useful for the design of chemo-immunotherapeutic strategies for the treatment of colorectal carcinoma in clinical trials.

Efficient generation of survivin-specific cytotoxic T lymphocytes from healthy persons in vitro: Quantitative and qualitative effects of CD4+ T cells

For the adoptive immunotherapy and the study of cytotoxic T lymphocytes (CTLs) in human, efficient in vitro generation of CTLs is needed. However, it is still difficult to induce T cells specific for naïve antigens in vitro even though dendritic cells (DCs) as potent APCs are used. In this study, we investigated quantitative and qualitative effects of CD4+ T cells during in vitro stimulation of CD8+ T cells from healthy donors using DCs transduced with adenovirus vector expressing human survivin (Adv-survivin). CTLs were not efficiently induced in the absence of CD4+ T cells or in CD25+ depleted CD4+ T cells. When the ratio of CD4+:CD8+ T cells was quantitatively decreased from 2:1 to 1:2, proliferation of CTLs specific for survivin was gradually increased. Because DCs pulsed with HCMV pp65 protein could activate CD4+ T cells to secrete Th1 cytokines, the use of pp65 protein as an adjuvant induced higher numbers and frequencies of CTLs. Furthermore, Th1 conditioning of CD4+ T cells augmented this generation of CTLs. These results suggest that both quantitative and qualitative modulation of CD4+ T cells including the number and Th1 polarization may be required for the efficient induction of CTLs specific for tumor antigens in vitro.

Efficient antitumor immunity in a murine colorectal cancer model induced by CEA RNA-electroporated B cells

RNA electroporation as a gene delivery method is more feasible and safer as compared with viral vectors. RNA‐loaded dendritic cells (DC) have been used to induce T cell responses against tumor rejection antigens and B cells can also act as antigen‐presenting cells for cellular vaccines. In this study, we compared B cells and DC, after electroporation with carcinoembryonic antigen (CEA) RNA, for their capacity to generate cytotoxic T lymphocytes and antitumor immunity. Vaccination using these B cells induced levels of IFN‐γ‐secreting T cells and cytotoxic T cells comparable to those induced by DC. Intravenous administration was the optimum route for the B cell vaccine, while subcutaneous administration was the optimum route for the DC vaccine. The B cell vaccine predominantly generated CEA‐specific CD4+ T cells, whereas the DC vaccine generated CD8+ T cells. Moreover, the B cell vaccine induced higher levels of anti‐CEA antibodies than the DC vaccine. A heterogeneous prime‐boost using B cells and DC failed to show any synergistic effects; however, the B cell vaccine did inhibit tumor growth and prolonged survival to a similar extent as the DC vaccine. Such RNA‐electroporated B cells may prove useful as cellular tumor vaccines with potential clinical application.

HLA-Cw polypmorphism and killer cell immunoglobulin-like receptor (KIR) gene analysis in Korean colorectal cancer patients

PURPOSE Natural killer cells (NK cells) play important roles in protecting the patient from the early development of cancers, and are activated or inhibited by killer cell immunoglobulin-like receptors (KIR), which bind to HLA class I. In the present study, we investigated the KIR genotype of Korean colorectal cancer patients. METHODS DNA samples were extracted from peripheral blood cell samples taken from Korean colorectal cancer patients and a control group. KIR genes were amplified using PCR-SSP methods, and HLA-Cw genes were characterized using PCR methods. The results were analyzed to assess the difference between colorectal cancer patients and the normal control group. RESULTS In the present study, the frequency of KIR2DS5 (33.2% vs. 20.8%, p-value < 0.007) was higher in the colorectal cancer group, and in the rectal cancer subgroup, the frequencies of KIR3DL1 (93.2%, vs. 98.1%, p-value < 0.05), KIR2DS2 (7.8% vs. 19.5%, p-value < 0.01), and KIR2DS4 (93.2% vs. 98.1%, p-value < 0.05) were lower significantly. The frequencies of HLA-Cw6 (9.1% vs. 15.7%, p-value < 0.05) and HLA-Cw7 (17.4% vs. 27.7%, p-value < 0.02) were lower in the colorectal cancer group. Of the patients with HLA-C1 homozygote, the frequency of KIR2DS2 was decreased significantly (5.8% vs. 14.5%, p-value < 0.004). CONCLUSIONS The frequency of KIR2DS5 is higher in Korean colorectal cancer patients, and in the rectal cancer subgroup, the frequencies of KIR3DL1, KIR2DS2 and KIR2DS4 are lower. Among the patients with HLA-C1 homozygote, the frequency of KIR2DS2 is decreased. Therefore, KIR2DS2 in presence of its ligand (HLA-C1 group) may have a protective effect against colorectal cancer.