CD4 and FOXP3 as predictive markers for the recurrence of T3/T4a stage II colorectal cancer: applying a novel discrete Bayes decision rule.

BACKGROUND: We recently reported the relapse-free survival (RFS) significance of the combination of CD4+ and forkhead box P3+ (FOXP3) T-cell densities identified by immunohistochemistry in patients with stage I, II, and III colorectal cancer (CRC) who underwent curative resections. This study was designed to determine the optimal combination of markers that predict recurrence in patients with T factors of T3/T4a stage II CRC by applying a novel Bayes decision rule. METHODS: Using 137 cancer tissue specimens from T3/T4a stage II patients, 12 clinicopathologic and immune factors were analysed as predictive candidates for recurrence. RESULTS: Our study showed that the combination of low CD4+ and low FOXP3+ T-cell densities resulted in extremely poor RFS. CONCLUSIONS: Adjuvant chemotherapy may be considered for patients with a combination of low CD4+ and low FOXP3+ T-cell densities. The discovery of this new prognostic indicator is important for the appropriate management of patients undergoing curative resection for T3/T4a stage II CRC.

Adoptive cell therapy using tumor-infiltrating lymphocytes for melanoma refractory to immune-checkpoint inhibitors.

To evaluate the feasibility of adoptive cell therapy (ACT) using ex vivo-expanded tumor-infiltrating lymphocytes (TILs) in Japanese patients with melanoma who failed immune-checkpoint inhibitor therapy, an open-label, single-arm, pilot study was conducted. We investigated the immunological and genetic factors of the pretreatment tumor and expanded TILs that may be associated with the clinical response. The treatment protocol comprised preparation of TIL culture, lympho-depleting non-myeloablative preconditioning with cyclophosphamide and fludarabine, TIL infusion, and intravenous administration of low-dose IL-2. Three patients of clinical subtypes mucosal, superficial spreading, and acral melanoma underwent TIL-ACT. Most severe adverse events, including fever and leukopenia, were manageable with the supportive regimen specified in the protocol, suggesting that the TIL-ACT regimen is suitable for Japanese patients with melanoma. One patient showed a short-term partial response, one relatively long-stable disease, and one experienced disease progression. Whole-exome and transcriptional sequencing of isolated tumor cells and immunohistochemical analyses before TIL-ACT revealed various immunostimulatory factors, including a high tumor mutation burden and immune cell-recruiting chemokines, as well as various immunosuppressive factors including TGF-ß, VEGF, Wnt/ß-catenin, and MAPK signaling and epithelial-to-mesenchymal transition, which might influence the efficacy of TIL-ACT. Our results imply mechanisms for the antitumor effect of and resistance to TIL-ACT. Further studies of immune-resistant mechanisms of TIL-ACT are warranted. This study is registered with the UMIN Clinical Trial Registry (UMIN 000011431).

Prospective observational study of the efficacy of nivolumab in Japanese patients with advanced melanoma (CREATIVE study).

BACKGROUND: Nivolumab, the anti-programmed cell death protein 1 antibody, has been approved for advanced melanoma, mainly based on evidence from Western countries. The profile of melanoma differs between Caucasian and Asian patients. This study was performed to obtain post-marketing data of nivolumab in Japanese patients with advanced melanoma. METHODS: This prospective, observational study involved patients with unresectable or metastatic melanoma treated with nivolumab at dosages of 2 mg/kg every 3 weeks or 3 mg/kg every 2 weeks. The primary endpoints were objective response rate and overall survival. The secondary endpoints were progression-free survival and the objective response rate according to immune-related Response Evaluation Criteria in Solid Tumours. RESULT: Among 124 patients analysed, mucosal melanoma was the most common subtype, followed by acral lentiginous, nodular, superficial spreading and lentigo maligna melanoma. Response Evaluation Criteria in Solid Tumours evaluation showed an objective response rate of 17.7%. The median survival time was 15.93 months, and the 1-year overall survival rate was 66%. Outcomes were not significantly different among melanoma subtypes. Better overall survival and/or progression-free survival but not objective response rate were associated with performance status 0, lower levels of lactate dehydrogenase, C-reactive protein and neutrophil-to-lymphocyte ratio. Patients with immune-related adverse events showed a better objective response rate, 3-month landmark overall survival and progression-free survival than patients without immune-related adverse events. CONCLUSION: The objective response rate and median survival time in Japanese patients treated with nivolumab were lower in daily practice than the >30% and >30 months, respectively, seen in global phase III trials. The occurrence of immune-related adverse events may be a predictor for survival and response to treatment with nivolumab.

Intratumoural-infiltrating CD4 + and FOXP3 + T cells as strong positive predictive markers for the prognosis of resectable colorectal cancer.

BACKGROUND: CD3 + and CD8 + T-cell infiltration were reported as positive predictive markers of survival in colorectal cancer (CRC) patients. Here, we demonstrate the prognostic significance of CD4 + and FOXP3 + T-cell densities in CRC. METHODS: We quantified the intratumoural densities of CD3 + , CD8 + , CD4 + and FOXP3 + T cells by immunohistochemistry and digital pathology in 342 CRC patients who underwent curative resection. Microsatellite instability was also assessed in 322 specimens. Patient demographics, clinicopathological features and survival rates were analysed. RESULTS: High CD3 + , CD4 + and FOXP3 + T-cell densities were associated with improved relapse-free survival (RFS); high CD8 + , CD4 + and FOXP3 + T-cell densities were associated with improved disease-specific survival (DSS). Patients with low CD4 + and low FOXP3 + T-cell densities exhibited extremely poor prognoses. T stage, vascular/lymphatic invasion and CD4 + T-cell density were independent prognostic indicators for DSS. The distributions of CD4 + and FOXP3 + T-cell densities were not significantly different between the high microsatellite instability group and other groups, in contrast to those of CD3 + and CD8 + T-cell densities. CONCLUSIONS: Intratumoural CD4 + T-cell density and combined CD4 + and FOXP3 + T-cell densities were stronger prognostic indicators than other clinicopathological features. These results may facilitate the establishment of novel prognostic factors and therapeutic strategies for CRC.

Correction: Intratumoural-infiltrating CD4 + and FOXP3 + T cells as strong positive predictive markers for the prognosis of resectable colorectal cancer.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Phase I pilot study of Wilms tumor gene 1 peptide-pulsed dendritic cell vaccination combined with gemcitabine in pancreatic cancer.

This study aimed to evaluate the feasibility of and immune response to Wilms tumor gene 1 (WT1) peptide-pulsed dendritic cell vaccination combined with gemcitabine (DCGEM) as a first-line therapy among patients with advanced pancreatic cancer. Ten HLA-A*2402 patients were treated with WT1 peptide-pulsed DC vaccination (1 × 10(7) cells) on days 8 and 22 and gemcitabine (1000 mg/m(2) ) on days 1, 8 and 15. Induction of a WT1-specific immune response was evaluated using the delayed-type hypersensitivity (DTH) skin test, interferon-γ enzyme-linked immunospot and HLA tetramer assays, along with assays for various immunological factors. DCGEM was well-tolerated, and the relative dose intensity of gemcitabine was 87%. Disease control associated with a low neutrophil/lymphocyte ratio was observed in all three patients with DTH positivity; it was also correlated with a low percentage of granulocytic myeloid derived suppressor cells in the pretreatment peripheral blood (P = 0.017). Patients with liver metastases and high levels of inflammatory markers such as C-reactive protein and interleukin-8 (IL-8) showed poor survival even though a WT1-specific immune response was induced in them. WT1 peptide-pulsed DCGEM is feasible and effective for inducing anti-tumor T-cell responses. Our results support future investigations for pancreatic cancer patients with non-liver metastases and favorable immunological conditions. This trial was registered with the University hospital Medical Information Network (UMIN) Clinical Trials Registry (http://www.umin.ac.jp/ctr/ number: UMIN-000004855).

A phase ΙI study of five peptides combination with oxaliplatin-based chemotherapy as a first-line therapy for advanced colorectal cancer (FXV study).

BACKGROUND: We previously conducted a phase I trial for advanced colorectal cancer (CRC) using five HLA-A*2402-restricted peptides, three derived from oncoantigens and two from vascular endothelial growth factor (VEGF) receptors, and confirmed safety and immunological responses. To evaluate clinical benefits of cancer vaccination treatment, we conducted a phase II trial using the same peptides in combination with oxaliplatin-based chemotherapy as a first-line therapy. METHODS: The primary objective of the study was the response rates (RR). Progression free survival (PFS), overall survival (OS), and immunological parameters were evaluated as secondary objective. The planned sample size was more than 40 patients for both HLA2402-matched and -unmatched groups. All patients received a cocktail of five peptides (3 mg each) mixed with 1.5 ml of IFA which was subcutaneously administered weekly for the first 12 weeks followed by biweekly administration. Presence or absence of the HLA-A*2402 genotype were used for classification of patients into two groups. RESULTS: Between February 2009 and November 2012, ninety-six chemotherapy naïve CRC patients were enrolled under the masking of their HLA-A status. Ninety-three patients received mFOLFOX6 and three received XELOX. Bevacizumab was added in five patients. RR was 62.0% and 60.9% in the HLA-A*2402-matched and -unmatched groups, respectively (p=0.910). The median OS was 20.7 months in the HLA-A*2402-matched group and 24.0 months in the unmatched group (log-rank, p=0.489). In subgroup with a neutrophil/lymphocyte ratio (NLR) of <3.0, patients in the HLA-matched group did not survive significantly longer than those in the unmatched group (log-rank, p=0.289) but showed a delayed response. CONCLUSIONS: Although no significance was observed for planned statistical efficacy endpoints, a delayed response was observed in subgroup with a NLR of <3.0. Biomarkers such as NLR might be useful for selecting patients with a better treatment outcome by the vaccination. TRIAL REGISTRATION: Trial registration: UMIN000001791.

Immune suppression and resistance mediated by constitutive activation of Wnt/ß-catenin signaling in human melanoma cells.

Cancer-induced immunosuppression is a major problem reducing antitumor effects of immunotherapies, but its molecular mechanism has not been well understood. We evaluated immunosuppressive roles of activated Wnt/ß-catenin pathways in human melanoma for dendritic cells (DCs) and CTLs. IL-10 expression was associated with ß-catenin accumulation in human melanoma cell lines and tissues and was induced by direct ß-catenin/TCF binding to the IL-10 promoter. Culture supernatants from ß-catenin-accumulated melanoma have activities to impair DC maturation and to induce possible regulatory DCs. Those immunosuppressive culture supernatant activities were reduced by knocking down ß-catenin in melanoma cells, partly owing to downregulation of IL-10. Murine splenic and tumor-infiltrating DCs obtained from nude mice implanted with human mutant ß-catenin-overexpressed melanoma cells had less ability to activate T cells than did DCs from mice with control melanoma cells, showing in vivo suppression of DCs by activated Wnt/ß-catenin signaling in human melanoma. This in vivo DC suppression was restored by the administration of a ß-catenin inhibitor, PKF115-584. ß-catenin-overexpressed melanoma inhibited IFN-γ production by melanoma-specific CTLs in an IL-10-independent manner and is more resistant to CTL lysis in vitro and in vivo. These results indicate that Wnt/ß-catenin pathways in human melanoma may be involved in immunosuppression and immunoresistance in both induction and effector phases of antitumor immunoresponses partly through IL-10 production, and they may be attractive targets for restoring immunocompetence in patients with Wnt/ß-catenin-activated melanoma.

Autocrine and paracrine loops between cancer cells and macrophages promote lymph node metastasis via CCR4/CCL22 in head and neck squamous cell carcinoma.

Lymph node metastasis is a poor prognostic factor for patients with head and neck squamous cell carcinoma (HNSCC). However, its molecular mechanism has not yet been fully understood. In our study, we investigated the expression of CCR4 and its ligand CCL22 in the HNSCC tumor microenvironment and found that the CCR4/CCL22 axis was involved in lymph node metastasis of HNSCC. CCR4 was expressed in 20 of 31 (64.5%) human tongue cancer tissues, and its expression was significantly correlated with lymph node metastasis (p < 0.01) and lymphatic invasion (p < 0.05). CCR4 was expressed in three of five human HNSCC cell lines tested. CCR4(+) HNSCC cells, but not CCR4(-) cells, showed enhanced migration toward CCL22, indicating that functional CCR4 was expressed in HNSCC cell lines. CCL22 was also expressed in cancer cells (48.4% of tongue cancer tissues) or CD206(+) M2-like macrophages infiltrated in tumors and draining lymph nodes. CCL22 produced by cancer cells or CD206(high) M2-like macrophages increased the cell motility of CCR4(+) HNSCC cells in vitro in an autocrine or paracrine manner. In the mouse SCCVII in vivo model, CCR4(+) cancer cells, but not CCR4(-) cells, metastasized to lymph nodes which contained CCL22 producing M2-like macrophages. These results demonstrate that lymph node metastasis of CCR4(+) HNSCC is promoted by CCL22 in an autocrine or M2-like macrophage-dependent paracrine manner. Therefore, the CCR4/CCL22 axis may be an attractive target for the development of diagnostic and therapeutic strategies for patients with HNSCC.

Cancer-testis antigen BORIS is a novel prognostic marker for patients with esophageal cancer.

Esophageal squamous cell cancer (ESCC) is one of the most common lethal tumors in the world, and development of new diagnostic and therapeutic methods is needed. In this study, cancer-testis antigen, BORIS, was isolated by functional cDNA expression cloning using screening technique with serum IgG Abs from ESCC patients. BORIS was previously reported to show cancer-testis antigen like expression, but its immunogenicity has remained unclear in cancer patients. BORIS was considered to be an immunogenic antigen capable of inducing IgG Abs in patients with various cancers, including four of 11 ESCC patients. Immunohistochemical study showed that the BORIS protein was expressed in 28 of 50 (56%) ESCC tissues. The BORIS expression was significantly associated with lymph node metastasis in ESCC patients with pT1 disease (P = 0.036). Furthermore, the patients with BORIS-positive tumors had a poor overall survival (5-year survival rate: BORIS-negative 70.0% vs BORIS-positive 29.9%, log-rank P = 0.028) in Kaplan-Meier survival analysis and log-rank test. Multivariate Cox proportional hazard model demonstrated that BORIS expression was an independent poor prognostic factor (hazard ratio = 4.158 [95% confidence interval 1.494-11.57], P = 0.006). Downregulation of BORIS with specific siRNAs resulted in decreased cell proliferation and invasion ability of ESCC cell lines. BORIS may be a useful biomarker for prognostic diagnosis of ESCC patients and a potential target for treatment including by BORIS-specific immunotherapy and molecular target therapy.

[Biomarkers for cancer immunotherapy].

Immune-biomarkers and -assays are important for development of cancer immunotherapy to select the patients who are expected to respond to immunotherapy before or early after immunotherapy, to monitor immune induction following immunotherapy, and to evaluate anti-tumor effects early after immunotherapy. Comprehensive immune-evaluation including positive and negative immune responses against cancer cells and identification of blood biomarkers which reflect immune-conditions in tumor microenvironment are required although direct evaluation of tumor tissues can be possible for some patients. Importance of immune responses has recently been recognized even for standard cancer treatments including chemotherapy and molecular target therapy. Therefore, immunological biomarkers may be useful for any cancer treatment.

Clinical Performance of the Consensus Immunoscore in Colon Cancer in the Asian Population from the Multicenter International SITC Study.

BACKGROUND: In this study, we evaluated the prognostic value of Immunoscore in patients with stage I−III colon cancer (CC) in the Asian population. These patients were originally included in an international study led by the Society for Immunotherapy of Cancer (SITC) on 2681 patients with AJCC/UICC-TNM stages I−III CC. METHODS: CD3+ and cytotoxic CD8+ T-lymphocyte densities were quantified in the tumor and invasive margin by digital pathology. The association of Immunoscore with prognosis was evaluated for time to recurrence (TTR), disease-free survival (DFS), and overall survival (OS). RESULTS: Immunoscore stratified Asian patients (n = 423) into different risk categories and was not impacted by age. Recurrence-free rates at 3 years were 78.5%, 85.2%, and 98.3% for a Low, Intermediate, and High Immunoscore, respectively (HR[Low-vs-High] = 7.26 (95% CI 1.75−30.19); p = 0.0064). A High Immunoscore showed a significant association with prolonged TTR, OS, and DFS (p < 0.05). In Cox multivariable analysis stratified by center, Immunoscore association with TTR was independent (HR[Low-vs-Int+High] = 2.22 (95% CI 1.10−4.55) p = 0.0269) of the patient's gender, T-stage, N-stage, sidedness, and MSI status. A significant association of a High Immunoscore with prolonged TTR was also found among MSS (HR[Low-vs-Int+High] = 4.58 (95% CI 2.27−9.23); p ≤ 0.0001), stage II (HR[Low-vs-Int+High] = 2.72 (95% CI 1.35−5.51); p = 0.0052), low-risk stage-II (HR[Low-vs-Int+High] = 2.62 (95% CI 1.21−5.68); p = 0.0146), and high-risk stage II patients (HR[Low-vs-Int+High] = 3.11 (95% CI 1.39−6.91); p = 0.0055). CONCLUSION: A High Immunoscore is significantly associated with the prolonged survival of CC patients within the Asian population.

Siglec-7 is a predictive biomarker for the efficacy of cancer vaccination against metastatic colorectal cancer.

Cancer immunotherapy, including vaccination, is considered a major scientific and medical breakthrough. However, cancer immunotherapy does not result in durable objective responses against colorectal cancer (CRC). To improve the efficacy of immunotherapy, the present study investigated several biomarkers for selecting patients who were expected to respond well to immunotherapy. Firstly, a comprehensive proteomic analysis was performed using tumor tissue lysates from patients enrolled in a phase II study, in which five human leukocyte antigen (HLA)-A*24:02-restricted peptides were administered. Sialic acid-binding immunoglobulin type lectin (Siglec)-7 was identified as a potential predictive biomarker. Subsequently, this biomarker was validated using western blot analysis, and immunofluorescence using tissue samples from the patients enrolled in the phase II study. The expression levels of Siglec-7 detected by immunofluorescence were quantified and their association with overall survival (OS) in patients treated with the peptide vaccine was examined. Furthermore, considering the important role of tumor-infiltrating lymphocytes (TILs) for CRC prognosis, the densities of CD3+, CD4+, CD8+ and forkhead box P3 (FOXP3)+ T cells in CRC tissues were examined and compared with Siglec-7 expression. The mean expression levels of Siglec-7 were significantly higher in patients with poor prognosis, with an OS of ≤2 years, as shown in comprehensive proteomic analysis (P=0.016) and western blot analysis (P=0.025). Immunofluorescence analysis demonstrated that Siglec-7 was expressed in intratumoral macrophages. The OS in patients with high Siglec-7 expression was significantly shorter than in that in patients with low Siglec-7 expression (P=0.017) in the HLA-A*24:02-matched patients. However, this difference was not observed in the HLA-unmatched patients. There was no significant difference in OS between patients according to the numbers of TILs, nor significant correlation between TILs and Siglec-7 expression. In conclusion, Siglec-7 expression in macrophages in tumor tissue may be a novel predictive biomarker for the efficacy of immunotherapy against metastatic CRC.

Dendritic cell based personalized immunotherapy based on cancer antigen research.

Human tumor antigens were identified using various immunological and genetic methods, and immune responses to the identified antigens were evaluated in cancer patients. Autologous tumor specific unique antigens derived from genetic alterations in cancer cells were isolated from patients with favorable prognosis after immunotherapy, indicating that they are attractive targets for immunotherapy. Immunogenicity of shared antigens was found to differ among patients due to antigen expression in cancer cells and patients' immunoreactivity. These observations suggest that personalization may be applied for cancer immunotherapy. We therefore developed intratumoral DC administration protocols that are able to induce immune responses to both unique and shared tumor antigens expressed in each individual cancer. By combining cryoablative tumor pretreatment and TLR stimulated DC, the anti-tumor effect of the intratumoral DC administration was significantly augmented in a murine tumor model. This improved protocol enhanced systemic induction of anti-tumor CD8+ CTL, and was able to regress relatively large remote untreated tumors. In clinical trials, systemic immune induction was observed by intratumoral DC administration following cryoablative tumor treatment, although anti-tumor effects are relatively weak, indicating that additional interventions are required for more effective immunotherapy.

Identification of a novel cancer-testis antigen CRT2 frequently expressed in various cancers using representational differential analysis.

PURPOSE: Cancer-testis antigens are promising targets for cancer immunotherapy. Identification of additional cancer-testis antigens with frequent expression in various cancers was attempted using representational differential analysis (RDA) and immunogenicity evaluation. EXPERIMENTAL DESIGN: cDNAs preferentially expressed in testis were enriched using RDA by subtraction between testis and normal tissues. Thirty clones showing cancer-testis-like expression based on EST database analysis were evaluated by reverse transcription-PCR. A potential antigen, CRT2, was identified and its expression was analyzed with a newly generated anti-CRT2 antibody. The immunogenicity of CRT2 was examined based on reactivity with serum immunoglobulin G (IgG) from cancer patients, using Western blot and ELISA analysis, and on in vitro induction of tumor-reactive CTLs from HLA-A24 transgenic mice and human peripheral blood lymphocytes. RESULTS: CRT2 was expressed in elongated spermatids of testis among normal tissues and in various cancer cell lines and tissues. The recombinant CRT2 protein was recognized by serum IgG from patients with various cancers in Western blot and ELISA analyses. A CRT2-derived peptide was identified as an HLA-A24-restricted T-cell epitope that induced tumor-reactive CTLs. CONCLUSION: CRT2 was identified as a new cancer-testis antigen expressed in elongated spermatids of testis and in cancer tissues (particularly melanoma) that is recognized by serum IgG from cancer patients. An HLA-A24-restricted T-cell epitope capable of inducing tumor-reactive CTLs was identified, suggesting that CRT2 may be useful for cancer diagnosis and immunotherapy.

Pilot study of WT1 peptide-pulsed dendritic cell vaccination with docetaxel in esophageal cancer.

In the present study, the immune response to Wilms tumor gene 1 (WT1) peptide-pulsed dendritic cell (DC) vaccination combined with docetaxel (DCDOC) in advanced esophageal cancer patients who had already received first-line chemotherapy was investigated. Ten HLA-A*2402 patients were treated with docetaxel (50 mg/m2) on day 1 and WT1 peptide-pulsed DC vaccination (1×107 cells) on days 15 and 22 (repeated every 4 weeks for 3 cycles). The delayed-type hypersensitivity skin test, HLA tetramer assay and interferon-γ enzyme-linked immunospot (ELISPOT) assay were used to evaluate the induction of a WT1-specific immune response. Median overall survival was 5 months (range, 1.1-11.6). The clinical effect of DCDOC therapy was not observed and only 1 patient could complete the protocol therapy. Disease progression was observed in 9 patients and 1 patient succumbed to fatality during the second cycle of therapy. As a pilot study, it was not possible to evaluate the safety of WT1 peptide-pulsed DCDOC therapy for esophageal squamous cell cancer. However, a WT1-specific response in 6 patients, as indicated by the ELISPOT or HLA/WT1-tetramer assay, was demonstrated. The results suggested that the positive immune response had significant relevance on the low percentage of CD11b+ and CD66b+ granulocytic myeloid-derived suppressor cells in CD15+ cells. Furthermore, DCDOC elicited a WT1-specific immune response regardless of the myelosuppression associated with docetaxel. The present findings support future studies and further work to assess DCDOC as an adjuvant therapy for esophageal cancer will be performed. The present clinical trial was registered in the University Hospital Medical Information Network (UMIN) Clinical Trials Registry on November 11th, 2011, no. UMIN000006704.

Clinical significance of serum p53 antibodies in patients with ulcerative colitis and its carcinogenesis.

BACKGROUND: For early detection of ulcerative colitis (UC)-associated colorectal cancer (CRC), surveillance colonoscopy is recommended in UC patients at high risk. However, poor acceptability deteriorates its effectiveness and a suitable marker for selecting patients at high risk is needed. Here we evaluated clinical usefulness of the measurement of anti-p53 antibodies (Abs) by enzyme-linked immunosorbent assay (ELISA) using sera samples from UC patients. METHODS: Sera from 286 patients with UC, 82 patients with sporadic CRC, and 63 healthy controls (HC) were obtained. Serum anti-p53 antibodies were detected with ELISA. Immunohistochemical detection was also performed in patients who developed dysplasia or CRC. RESULTS: Serum p53 Ab was positive in 15.0% of UC, while it was positive only in 1.6% of HCs. In sporadic CRCs, 52.4% of 82 patients were positive. In UC patients with disease duration equal to or longer than 8 years, positivity of serum p53 Ab was significantly higher than those in patients with shorter duration. Eight of 13 (61.5%) UC patients with CRC or dysplasia were positive for serum p53 Abs, which was significantly higher than that in patients without neoplasia. All UC patients with CRC were positive for p53 staining, while 2 were negative for serum p53 Ab. Finally, levels of serum p53 Ab had fallen in 4 patients with CRC we could monitor after surgery. CONCLUSIONS: This study revealed that p53 Ab developed in the progression of UC-associated CRC but not in all patients with neoplasia, suggesting that serological detection of p53 Abs by ELISA is not suitable in primarily selecting patients at high risk; however, it is helpful in salvaging patients who drop from a surveillance program.

A novel cancer testis antigen that is frequently expressed in pancreatic, lung, and endometrial cancers.

PURPOSE: To isolate cancer testis antigens that are expressed in pancreatic cancers and may be useful in clinical applications. EXPERIMENTAL DESIGN: To efficiently isolate cancer testis antigens, a testis cDNA library was immunoscreened (SEREX) with serum from a patient with pancreatic ductal adenocarcinoma. The expression of isolated antigens in various cancer cell lines and tissues was evaluated by reverse transcription-PCR and Northern blot analyses. The immunogenicity of the antigen in cancer patients was evaluated by detection of the IgG antibody in sera from patients with various cancers. RESULTS: Of the three clones isolated through screening of a total of 2 x 10(6) cDNA library clones, one clone (KU-CT-1) was found to be expressed in various cancers but only in testis among normal tissues, indicating that it was a novel cancer testis antigen. The KU-CT-1 gene is located on chromosome 10p12 and produces two splice variants, which encode proteins of 397 and 872 amino acids, respectively. KU-CT-1 was expressed in pancreatic cancer tissues (3 of 9, 33%), lung cancer tissues (9 of 24, 38%), and endometrial cancer tissues (7 of 11, 64%). Specific serum IgG antibodies were detected in 3 of 20 pancreatic cancer patients, 2 of 12 endometrial cancer patients, 1 of 18 colon cancer patients, and 1 of 10 prostate cancer patients but not detected in 30 healthy individuals. CONCLUSIONS: KU-CT-1 is a new cancer testis antigen that is expressed in pancreatic, lung, and endometrial cancers and may be useful for diagnosis and immunotherapy for patients with various cancers.

Progression of Human Renal Cell Carcinoma via Inhibition of RhoA-ROCK Axis by PARG1.

Renal cell carcinoma (RCC) is the most lethal urological malignancy with high risk of recurrence; thus, new prognostic biomarkers are needed. In this study, a new RCC antigen, PTPL1 associated RhoGAP1 (PARG1), was identified by using serological identification of recombinant cDNA expression cloning with sera from RCC patients. PARG1 protein was found to be differentially expressed in RCC cells among patients. High PARG1 expression is significantly correlated with various clinicopathological factors relating to cancer cell proliferation and invasion, including G3 percentage (P = .0046), Ki-67 score (p expression is also correlated with high recurrence of N0M0 patients (P = .0084) and poor prognosis in RCC patients (P = .0345). Multivariate analysis has revealed that high PARG1 expression is an independent factor for recurrence (P = .0149) of N0M0 RCC patients. In in vitro studies, depletion of PARG1by siRNA in human RCC cell lines inhibited their proliferation through inducing G1 cell cycle arrest via upregulation of p53 and subsequent p21Cip1/Waf1, which are mediated by increased RhoA-ROCK activities. Similarly, PARG1 depletion cells inhibited invasion ability via increasing RhoA-ROCK activities in the RCC cell lines. Conversely, overexpression of PARG1 on human embryonic kidney cell line HEK293T promotes its cell proliferation and invasion. These results indicate that PARG1 plays crucial roles in progression of human RCC in increasing cell proliferation and invasion ability via inhibition of the RhoA-ROCK axis, and PARG1 is a poor prognostic marker, particularly for high recurrence of N0M0 RCC patients.

Peptide-pulsed dendritic cell vaccine in combination with carboplatin and paclitaxel chemotherapy for stage IV melanoma.

In this study, we aimed to evaluate the feasibility and efficacy of peptide-pulsed dendritic cell (DC) vaccine in combination with carboplatin and paclitaxel chemotherapy (DCCP) for patients with stage IV melanoma previously treated with dacarbazine-containing regimen. Six HLA-A24 and 3 HLA-A02 patients were treated with carboplatin (area under the curve 5) and paclitaxel (175 mg/m) on day 1 and DCs (2×10 cells) pulsed with Wilms tumor gene 1 (WT1), gp100, tyrosinase, and either MAGE-A3 (for HLA-A24) or MAGE-A2 (for HLA-A02) peptides on days 8 and 22 in 28-day cycle for up to three cycles. DCCP was well tolerated, and median progression-free survival and median overall survival were 2.3 and 12.0 months, respectively. In four of nine patients, a WT1-specific immune response (WT1-IR) was detected using the interferon-γ enzyme-linked ImmunoSpot assay and WT1/HLA tetramer assay. DCCP was more likely to elicit a WT1-IR in patients who received DCs pulsed with the HLA-A24-restricted peptide (75%) compared with patients who received DCs pulsed with the HLA-A02-restricted peptide (0%, P=0.058). Furthermore, three (75%) of four patients with a WT1-IR survived longer than 12 months, whereas only one (20%) of five patients without a WT1-IR who received the BRAF inhibitor after DCCP survived longer than 12 months. These results suggest that DCCP may be beneficial for HLA-A24 melanoma patients with a WT1-IR.