Identification of antibody against wingless‑type MMTV integration site family member 7B as a biliary cancer tumor marker

Biliary cancer has a poor prognosis due to a lack of specific biomarkers and difficulty in diagnosis. The present study aimed to identify serum tumor markers for the diagnosis of biliary cancer via serological identification of antigens by recombinant cDNA expression cloning. Wingless‑type MMTV integration site family, member 7 (WNT7B) was identified as a target antigen, suggesting the presence of serum antibodies against this antigen. Deletion mutants were then prepared to evaluate the response to serum antibodies. When serum antibody levels against WNT7B deletion mutants (WNT7B_-92‑2, _-92‑260, _2-260 and _184-260) were examined using amplified luminescence proximity homogeneous assay‑linked immunosorbent assay, the levels of the antibody against WNT7B with amino acids 184‑260 were higher in patients with biliary cancer than in healthy donors. Therefore, the region covering residues 184‑260 of WNT7B was decomposed to generate seven peptides, and the levels of antibodies against these peptides were measured. Among them, the levels of antibodies against WNT7B_234‑253 and WNT7B_244‑260 were higher in patients with biliary cancers than in healthy donors (WNT7B_234‑253, P=0.0009; WNT7B_244‑260, P=0.0005). The levels of the antibody against the former were specifically high in patients with biliary cancer but not in those with esophageal, gastric, colorectal, pancreatic, or breast cancer. Furthermore, analysis by the cutoff value of WNT7B_234‑253 defined by ROC showed a high sensitivity of 70% in patients with biliary cancer. Therefore, the serum levels of the antibody against WNT7B_234‑253 may be useful as a marker for biliary cancer diagnosis.

A case of thymic basaloid carcinoma with rectal carcinoma

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Thymic basaloid carcinoma is one of the rarest subtypes of thymic carcinoma.

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To our knowledge, this is the first case report of thymic basaloid carcinoma concurrent another carcinoma.

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Aggressive treatment including surgery should be considered aiming at radical cure.

Introduction

Thymic basaloid carcinoma is rare, as only about 40 reports have described it since the initial report. Thymoma and thymic carcinomas increase the risk of other malignancies, but concurrent thymic basaloid carcinoma and another malignancy has not been reported. We presented a rare case of thymic basaloid carcinoma with rectal carcinoma.

Case presentation

Computed tomography revealed an anterior mediastinal mass and rectal wall thickening, and colonoscopy identified a rectal type 2 tumor in a 68-year-old man. Total thymectomy via a median sternotomy was performed, and the thymic tumor was histopathologically confirmed as stage II thymic basaloid carcinoma. Subsequent laparoscopic low anterior resection indicated stage IIIa rectal carcinoma. Adjuvant chemotherapy was administered for the rectal cancer.

Discussion

Concurrent thymic and extrathymic tumors is rare condition. There are few reports of thymic basaloid carcinoma, and it is unclear whether this tumor, like common thymoma, increase the risk of extrathymic malignancies. Further studies in more patients are needed to elucidate the nature of this tumor.

Conclusion

To our knowledge, this is the first case report of thymic basaloid carcinoma concurrent another carcinoma. Aggressive treatment including surgery should be considered aiming at radical cure.

Role of Dimerized C16orf74 in Aggressive Pancreatic Cancer: A Novel Therapeutic Target

Over the past 30 years, the therapeutic outcome for pancreatic ductal adenocarcinoma (PDAC) has remained stagnant due to the lack of effective treatments. We performed a genome-wide analysis to identify novel therapeutic targets for PDAC. Our analysis showed that Homo sapiens chromosome 16 open reading frame 74 (C16orf74) was upregulated in most patients with PDAC and associated with poor prognosis. Previously, we demonstrated that C16orf74 interacts with the catalytic subunit alpha of protein phosphatase 3 and plays an important role in PDAC invasion. However, the pathophysiologic function of C16orf74 is still unclear. In this study, through the analysis of C16orf74 interaction, we demonstrate a new strategy to inhibit the growth and invasion of PDAC. C16orf74 exists in the homodimer form under the cell membrane and binds integrin αVβ3 and is also involved in invasion by activating Rho family (Rac1) and MMP2. Considering that this dimeric form was found to be involved in the function of C16orf74, we designed an 11R-DB (dimer block) cell-permeable dominant-negative peptide that inhibits the dimer form of C16orf74. 11R-DB suppressed invasion and proliferation of PDAC cell lines by inhibiting phosphorylation of Akt and mTOR and also by inactivation of MMP2. 11R-DB also showed antitumor effects in an orthotopic xenograft model and peritoneal metastasis model. Thus, this study demonstrates that dimerized C16orf74, present in the cell membrane, is involved in pancreatic cancer invasion and proliferation. In addition, the C16orf74 dimer block cell-permeable peptide (11R-DB) has a potent therapeutic effect on PDAC in vitro and in vivo.

5-Aminolevulinic-acid-mediated Photodynamic Diagnosis Enhances the Detection of Peritoneal Metastases in Biliary Tract Cancer in Mice

BACKGROUND/AIM

Previous studies on the accuracy of 5-aminolevulinic-acid-mediated photodynamic diagnosis (5-ALA PDD) have been reported for various cancers and brain surgery. However, biliary tract cancer is rare. Therefore, 5-ALA PDD has not been fully evaluated in biliary tract cancers. Small biliary tract cancer lesions such as peritoneal dissemination, liver metastases, and lymph node metastases are negative prognosticators in patients with biliary cancer. The purpose of this exploratory study was to determine if 5-ALA PDD could detect small biliary tract cancer lesions in murine models of biliary cancers.

MATERIALS AND METHODS

Biliary cancer cell lines (TFK-1, HuCCT-1, G415, HuH28, SSP25, RBE, KKU055 and KKU100) and Normal human dermal fibroblast cells were used to evaluate protoporphyrin IX (PpIX) accumulation in vitro. Subcutaneous tumor mice were established using two cell lines (TFK-1 and HuCCT-1). 5-ALA (250 mg/kg) was administered intraperitoneally, and fluorescent 5ALA-PDD was performed 3 h later to evaluate tumoral PpIX accumulation. A murine peritoneal disseminated nodule model was established by intraperitoneal injection of TFK-1 cells. Four weeks later, 5-ALA was administered intraperitoneally, and 5-ALA-PDD was performed 3 h post administration to evaluate PpIX accumulation in the disseminated nodules. The presence of tumor cells in tumors and nodules was confirmed by haematoxylin and eosin staining.

RESULTS

Compared TO non-cancerous cell lines, PpIX accumulation was increased in biliary tract cancer cell lines. PpIX accumulation led to a strong fluorescent signal in all subcutaneous tumors. In the murine model of peritoneal dissemination, microdisseminated nodules (<1 mm) that could not be detected under white light were clearly visible using 5-ALA-PDD.

CONCLUSION

5-ALA PDD was useful for diagnosis of biliary tract cancer and detection of small peritoneal metastatic lesions in murine models of biliary cancers. Clinical studies and applications of 5-ALA PDD for biliary tract cancer are expected in the future.

Identification of novel serum autoantibodies against EID3 in non-functional pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (pNETs) are relatively rare heterogenous tumors, comprising only 1–2% of all pancreatic neoplasms. The majority of pNETs are non-functional tumors (NF-pNETs) that do not produce hormones, and as such, do not cause any hormone-related symptoms. As a result, these tumors are often diagnosed at an advanced stage because patients do not present with specific symptoms. Although tumor markers are used to help diagnosis and predict some types of cancers, chromogranin A, a widely used tumor marker of pNETs, has significant limitations. To identify novel NF-pNET-associated antigens, we performed serological identification of antigens by recombinant cDNA expression cloning (SEREX) and identified five tumor antigens (phosphatase and tensin homolog, EP300-interacting inhibitor of differentiation 3 [EID3], EH domain-containing protein 1, galactoside-binding soluble 9, and BRCA1-associated protein). Further analysis using the AlphaLISA^® immunoassay to compare serum antibody levels revealed that antibody levels against the EID3 antigen was significantly higher in the patient group than in the healthy donor group (n = 25, both groups). In addition, higher serum anti-EID3 antibody levels in NF-pNET patients correlated with shorter disease-free survival. The AUC calculated by ROC analysis was 0.784 with moderate diagnostic accuracy. In conclusion, serum anti-EID3 antibody levels may be useful as a tumor marker for prediction of tumor recurrence in NF-pNETs.

CD40 Expression in Human Esophageal Squamous Cell Carcinoma Is Associated with Tumor Progression and Lymph Node Metastasis

BACKGROUND

The co-stimulatory molecule cluster of differentiation 40 (CD40) is widely expressed in various types of malignant tumors, but its role remains unclear. The purpose of this study was to investigate the relationship between CD40 expression and clinicopathological variables in patients with esophageal squamous cell carcinoma (ESCC), as well as the function of CD40 expressed on ESCC tumor cells in vitro.

MATERIALS AND METHODS

Tumor specimens of patients who underwent surgical resection for ESCC were immunohistochemically analyzed for CD40 expression.

RESULTS

Of the 122 specimens, 45 (37%) were positive for CD40. Significant positive correlation was found between CD40 expression and p-stage (p=0.0011), histopathological grade (p=0.0143), pT-classification (p=0.0011), and pN-classification (p=0.0007). Survival of patients with stage III and IV disease with positive CD40 expression was significantly shorter than that of those with negative expression (log-rank test, p=0.0422). In in vitro analysis, while the addition of recombinant human CD154 did not inhibit growth, it did induce a significant increase in interleukin 6 production in ESCC cell lines.

CONCLUSION

These results suggest that functional expression of CD40 on tumor cells might play an important role in tumor progression and lymph node metastasis in ESCC.

Abstract A135: Novel immunotherapy for intractable pancreatic cancer focusing on the myeloid derived suppressor cells in the tumor microenvironment

Pancreatic cancer is one of malignant diseases with poor prognosis. Despite the recent progress for preoperative neoadjuvant chemoradiotherapy, the long term prognosis is still poor to make forward new treatment strategy. We have recently reported novel mechanism of anticancer reagents to impact patients' prognosis improving tumor microenvironment other than its direct cytotoxic effects (Ann Surg Oncol 2013, Cancer Sci 2014). The underlying mechanism include inhibition of HLA class I down regulation and Treg infiltration, increase of CD4 and CD8 T cell infiltration (Int J Clin Oncol 2015, Cancer Res 2015). Here we report that GM-CSF production was significantly enhanced in various PDAC cell lines after treatment with chemotherapy including gemcitabine or 5-FU, which induced the differentiation of CD14 positive monocytes into myeloid-derived suppressor cells (MDSC). This differentiation was promoted through MAPK signal pathway or NFkB pathway. Furthermore, blockade of GM-CSF with monoclonal antibodies helped to restore T-cell proliferation when co-cultured with monocytes stimulated with tumor supernatants. GM-CSF expression was also observed in primary tumors and correlated with poor prognosis in 68 PDAC patients analyzed by immunohistochemistry. We expect that postoperative prognosis of pancreatic cancer would be more improved by multidisciplinary strategy targeting MDSC and GM-CSF followed by curative surgical intervention.

Citation Format: Takahiro Tsuchikawa, Shintaro Takeuchi, Toru Nakamura, Mizuna Takahashi, kazuho Inoko, Toshihiro Kushibiki, Koji Hontani, Masato Ono, Shota Kuwabara, Toshiaki Shichinohe, Satoshi Hirano. Novel immunotherapy for intractable pancreatic cancer focusing on the myeloid derived suppressor cells in the tumor microenvironment [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr A135.