Angiotensin converting enzyme-independent,local angiotensin II-generation in human pancreatic ductal cancer tissues

Hypovascularity is an outstanding characteristic of pancreatic ductal cancer by diagnostic imaging: most pancreatic ductal cancers are hypovascular or avascular, and tumor vessels are seldom seen on angiography. However, we found that the vasculature was not always poor on angiography of surgically resected specimens of locally advanced pancreatic ductal cancers. To elucidate these controversial findings, we focused on angiotensin II, a vasoconstrictor which is directly produced from angiotensinogen at acidic pH by active trypsin. We examined whether a local angiotensin II-generating system exists in pancreatic ductal cancer tissue. We measured angiotensin II concentration and angiotensin converting enzyme (ACE) activity in tissues from normal pancreas, pancreatic ductal cancers, colon cancers, and hepatocellular carcinomas. After surgically resected specimens were homogenized, angiotensin II concentration and ACE activity in tissues were measured using the florisil method and the Kasahara method, respectively. Tissue angiotensin II levels in pancreatic ductal cancer (n=13) were significantly higher than those of normal pancreas (n=7), colon cancers (n=7), or hepatocellular carcinomas (n=7). However, there was no significant difference in the ACE activity in tissue between them. This study provides in vivo evidence of an ACE-independent, angiotensin II-generating system in pancreatic ductal cancer tissues and suggests that locally formed angiotensin II may act on the pre-existing pancreatic arteries around the tumor, leading to formation of hypovascular or avascular regions.     

Angiotensin II activates MAP kinase and NF-kappaB through angiotensin II type I receptor in human pancreatic cancer cells

Pancreatic ductal cancer has higher angiotensin II concentrations compared with normal pancreas or other solid tumors. This study examined angiotensin II type 1 (AT1) receptor expression and the role of angiotensin II in proliferation and survival of human pancreatic cancer cells. All three pancreatic cancer cell lines studied, from well to poorly-differentiated types, HPAF-II, AsPC-1, and Panc-1, showed strong expression of AT1 receptor. In contrast, HT-29 human colon cancer cells showed extremely weak expression. Angiotensin II stimulated the growth of pancreatic cancer cells through MAP kinase activation but had no significant effect on proliferation of HT-29 colon cancer cells. In addition, angiotensin II significantly prevented cisplatin (CDDP)-induced apoptosis through NF-kappaB activation and the subsequent production of anti-apoptotic molecules, including survivin and Bcl-XL, in pancreatic cancer cells. These findings suggest that angiotensin II plays a role in the growth and chemoresistance of AT1-positive pancreatic cancer cells through its action as a potent mitogen and anti-apoptotic molecule.     

Enhanced expression of annexin II in human pancreatic carcinoma cells and primary pancreatic cancers

Annexin II is a calcium and phospholipid binding protein anda substrate for protein-tyrosine kinases. Recent investigationshave revealed involvement of annexin II in DNA synthesis andcell proliferation. Increased levels of annexin II are observedin cancer cells and tissues. To investigate the expression ofannexin II in pancreatic adenocarcinoma cells and primary tumors,we measured the levels of annexin II mRNA and protein in normalhuman pancreas, five established human pancreatic adenocarcinomacell lines, three primary pancreatic cancers and one metastatictumor. All five cell lines examined had 5- to 15-fold higherlevels of annexin II as compared to normal pancreas. Significantelevations (2-to 8-fold) of annexin II expression were observedin the three primary pancreatic tumors and one metastatic tumorexamined. Immunocytochemical analysis indicates that the increasedexpression of annexin II is limited to proliferating ductularadenocarcinoma, and annexin II expression co-localizes withcells that express PCNA. In normal pancreas, annexin II expressionis seen in ductal and ductular cells and no expression is seenin acinar or islet cells. We conclude from these findings thatannexin II has a role in cell proliferation and its regulationis altered in pancreatic cancer.     

新型冠状病毒细胞受体血管紧张素转化酶II在消化道及其肿瘤中的表达

目的:由于新型冠状病毒（Corona Virus Disease 2019，COVID-19）可通过血管紧张素转化酶II（angiotensin-converting-enzyme II，ACE2）细胞受体进入宿主细胞，前期研究显示ACE2 mRNA在正常消化道细胞中表达，但ACE2蛋白在正常消化道中的表达以及ACE2 mRNA及其蛋白在消化道肿瘤中的表达未见报道。因此，本文旨在探索消化系统肿瘤中ACE2的表达情况，以期为消化系统肿瘤患者防治COVID-19提供参考。方法:通过GEPIA在线分析网站和HPA数据库对消化系统肿瘤中ACE2的mRNA和蛋白表达情况进行分析。结果:在所有正常组织中，消化道中的ACE2 mRNA及蛋白表达均较高。在所有肿瘤组织中，消化道肿瘤的ACE2蛋白表达也较高。ACE2 mRNA在肺癌、结肠癌、食管癌和胃癌中的表达均高于正常组织，且结肠癌和胃癌的ACE2 mRNA表达差异有统计学意义；此外，结肠癌和胃癌中ACE2的表达也高于肺癌。结论:ACE2在人类消化道中的表达相对更高，为消化道传播可能是COVID-19的感染途径提供了一定证据，并且消化道肿瘤患者的ACE2表达相对其正常组织表达更高，为预防消化道这一可能的感染途径，应高度重视消化道肿瘤患者的防护。     

Overexpression of connexin 26 in carcinoma of the pancreas

Contrary to the previously purported role of gap junction (GJ) associated-protein connexin 26 (Cx26) as a tumor suppressor, increased expression of Cx26 has recently been demonstrated in several human malignancies. Surprisingly, this high expression is reportedly related to poor prognosis in squamous cell lung carcinoma and breast cancer. In this study, we examined levels of Cx26 in various human gastrointestinal (GI) carcinomas, with a focus on pancreatic carcinomas, using immunohistochemistry. Many GI carcinomas displayed abundant Cx26 expression, predominantly in the cytoplasm. Cx26 was detected in 5/8 gastric cancers (62.5%), 6/8 squamous cell carcinomas of the esophagus (75.0%), 7/8 pancreatic cancers (87.5%) and 7/8 colon cancer cases (87.5%). However, Cx26 expression was not present in hepatocellular carcinoma (HCC, 0/8). Extensive immunohistochemical examination was performed on pancreatic carcinomas, revealing strong expression of Cx26 protein in 30/43 cases (70%), weak expression in 6/43 (14%) and no expression in 7/43 (16%). The present study demonstrated up-regulated Cx26 expression in a considerable percentage of GI carcinomas, with the exception of HCC. Our findings suggest that Cx26 may be involved in some of the malignant processes of GI cancers, and especially in pancreatic carcinomas.     

Overexpression of beta 1,4N-acetylgalactosaminyl- transferase mRNA as a molecular marker for various types of cancers

OBJECTIVE: To determine GalNAcT mRNA expression in human carcinoma cell lines and primary tumor tissues. Assessment of the potential use of GalNAcT mRNA as a molecular marker for detection of metastatic cancer cells in the peripheral blood of patients with hepatocellular carcinoma. METHODS/RESULTS: We investigated GalNAcT mRNA expression in various human cancer cell lines and primary cancer tissues using RT-PCR assay for GalNAcT mRNA. The expression of GalNAcT mRNA was detected in 25 of 26 cancer cell lines tested and in the majority of primary tumors from different organs: 8 of 10 colon cancers, 9 of 9 breast cancers, 11 of 12 esophageal cancers, 14 of 14 gastric cancers, 4 of 18 pancreatic cancers, 6 of 12 biliary tract cancers, 17 of 18 hepatocellular carcinomas and 13 of 14 lung cancers. Semi-quantitative analysis with duplex RT-PCR showed that the amount of the GalNAcT mRNA was enhanced in cancer tissues as compared to the surrounding cancer-free tissues. Blood specimens of 5 of 14 patients with hepatocellular carcinoma were positive for GalNAcT mRNA, all of whom developed recurrent disease in less than 24 months. Peripheral blood samples of 30 normal subjects were negative for GalNAcT mRNA. CONCLUSION: Our results suggest that the RT-PCR assay for GalNAcT mRNA could be a potentially useful molecular marker for detecting cancer dissemination in blood circulation of patients with malignancy.     

Reduced PTEN expression in the pancreas overexpressing transforming growth factor-beta 1

PTEN is a candidate tumour suppressor gene and frequently mutated in multiple cancers, however, not in pancreatic cancer. Recently, it has been demonstrated that PTEN expression is regulated by TGF-beta1. Using TGF-beta1 transgenic mice (n=7) and wildtype littermates (n=6), as well as pancreatic tissues obtained from organ donors (n=10) and patients with pancreatic cancer (n=10), we assessed the expression of PTEN by means of immunohistochemistry and semiquantitative PCR analysis. In addition, PANC-1 cells were treated with TGF-beta1 in vitro and the levels of PTEN mRNA were determined in these cells. In human pancreatic cancers PTEN mRNA levels were significantly decreased (P<0.05). In addition, in the pancreas of TGF-beta1 transgenic mice the expression of PTEN was significantly reduced (P<0.01), as compared to wildtype littermates and incubation of PANC-1 cells with TGF-beta1 decreased PTEN mRNA levels after 24 h. Inasmuch as TGF-beta1 decreases PTEN expression in human pancreatic cancer cells and human pancreatic cancers overexpress TGF-beta1, the reduced expression of PTEN in pancreatic cancer may be mediated by TGF-beta1 overexpression. Thus, although PTEN is not mutated in pancreatic cancers, the reduction of its expression may give pancreatic cancer cells an additional growth advantage.     

Differential expression of TRAIL-R3 and TRAIL-R4 in human pancreatic cancer

BACKGROUND: Pancreatic cancer is one of the most aggressive cancers, in part due to its insensitivity to most treatment modalities. This resistance towards cytotoxic therapy is thought to be caused--at least in part--by a general resistance of pancreatic cancer cells towards apoptosis. TRAIL-R3 and TRAIL-R4, which belong to the TRAIL receptor family, can inhibit TRAIL-induced apoptosis. PATIENTS AND METHODS: Seven normal pancreatic tissues and 7 pancreatic cancer tissues were analyzed using Northern blotting, Western blotting and immunohistochemistry. RESULTS: TRAIL-R3 mRNA and protein expression were generally weak in pancreatic cancers and normal pancreatic tissues. In contrast, TRAIL-R4 mRNA and protein were expressed at moderate to high levels in human pancreatic cancer tissues, but demonstrated weak to negative expression in the normal pancreas. CONCLUSION: TRAIL-R4 but not TRAIL-R3 levels were significantly different in pancreatic cancer in comparison to the normal pancreas. These findings give new insight into the resistance mechanisms of pancreatic cancer towards TRAIL-mediated apoptosis.     

Expression of a fibroblast growth factor-binding protein during the development of adenocarcinoma of the pancreas and colon

The activity of growth factors is crucial for tumor progression. We previously characterized a secreted fibroblast growth factor-binding protein (FGF-BP1) as a chaperone molecule, which enhances the biological functions of FGFs by releasing FGFs from the extracellular matrix. Here, we characterize the frequency and pattern of FGF-BP1 expression during the malignant progression of pancreas and colorectal carcinoma. For this, we generated monoclonal antibodies that detect FGF-BP1 protein in formalin-fixed, paraffin-embedded tissues and applied in situ hybridization to detect FGF-BP1 mRNA in adjacent tissue sections. FGF-BP1 protein and mRNA were found up-regulated (>70% positive) in parallel (r = 0.70, P < 0.0001) in colon adenoma (n = 9) as well as primary (n = 46) and metastatic (n = 71) colorectal cancers relative to normal colon epithelia (all P < 0.0001, versus normal). Similarly, pancreatitis (n = 17), pancreatic intraepithelial neoplasia (n = 80), and pancreatic adenocarcinoma (n = 67) showed a significant up-regulation of FGF-BP1 compared with normal pancreas (n = 42; all P < 0.0001, relative to normal). Furthermore, the biological activity of FGF-BP1 is neutralized by one of the antibodies, suggesting the potential for antibody-based therapeutic targeting. We propose that the up-regulation of the secreted FGF-BP1 protein during initiation of pancreas and colon neoplasia could make this protein a possible serum marker indicating the presence of high-risk premalignant lesions.     

血清CA19—9的酶免测定及临床应用

本文用生物素—链霉亲和素酶联免疫吸附试验（BSA）对203例血清CA19－9水平进行定量测定。结果显示，在32例胰腺癌组为826±411U／ml，40例肝癌组为107±46．5U／ml，与76例正常人对照组21．2±9．24U／ml比较均有明显差异（P＜0．05），以胰腺癌组升高最显著。在39例胃癌组为25．4±11．0U／ml，与正常对照组比较均无明显差异（P＞0．05）。27例胰腺癌病人术前为910±452U／ml，术后为187±89．0U／ml，血清CA19－9水平明显下降（P＜0．05）。血清CA19－9水平分析对胰腺癌的鉴别诊断、疗效观察及预后评估有较高价值。     

Characterization of cytokeratin 20 expression in pancreatic and colorectal cancer.

Cytokeratin 20 belongs to the epithelial subgroup of the intermediate filament family. Because of its restricted range of expression in humans, it has become an important tool for detecting and identifying metastatic cancer cells by immunohistochemistry and by PCR analysis. Despite its widespread diagnostic use in colorectal cancer and occasional use in pancreatic cancer, little is known about the expression of CK 20 in these tumors in vivo. Therefore, in the present study we characterized CK 20 expression in pancreatic and colorectal cancer by comparison with its expression in the normal pancreas and colon. Tissue samples from 24 patients with pancreatic cancer and from 41 patients with colorectal cancer were examined for CK 20 expression by Northern blot analysis, immunohistochemistry, and in situ hybridization. CK 20 expression was observed in the cancer cells of both cancer types. A subgroup of the pancreatic cancers exhibited a 3.2-fold increase in CK 20 mRNA by comparison with respective normal controls. In contrast, colon cancers underexpressed CK 20 mRNA by comparison with the respective controls. In the normal tissues, CK 20 immunoreactivity was relatively faint and sparse in the pancreatic ductal cells but intense and abundant in the apical portions of the colonic mucosa. CK 20 immunoreactivity was also evident in the ductal cells from the chronic pancreatitis-like lesions adjacent to the cancer cells. Furthermore, distant metastases from pancreas carcinomas exhibited strong CK 20 immunoreactivity. It is concluded that CK 20 is overexpressed in pancreatic cancer and that it can serve as an excellent marker for metastatic pancreatic cancer.     

Expression of receptors for gut peptides in human pancreatic adenocarcinoma and tumour-free pancreas.

Gut hormones that modulate the growth of normal pancreas may also modulate the growth of cancers originating from pancreas. This study visualized and compared the receptors for cholecystokinin (CCK), bombesin (BBS), secretin and vasoactive intestinal peptide (VIP) in tumour-free tissue sections of human pancreas (n = 10) and pancreatic ductal adenocarcinomas (n = 12) with storage phosphor autoradiography using radioligands. CCK-B receptors, present in control pancreata, were not detected in any of the pancreatic cancers. BBS receptors were visualized in control pancreata, but they were absent in 10 of 12 pancreatic cancers. In 5 of 12 pancreatic cancers, receptors for secretin were visualized, while binding for secretin was present in all tumour-free pancreata. Conversely, no specific binding of VIP was detected in control pancreata but was identified in 3 of 12 pancreatic cancer specimens. It is concluded that the expression of gut peptide receptors in pancreatic cancer differs from that in tumour-free pancreas. Receptors for these peptides are present in only a minority of pancreatic cancer specimens.     

Renin-angiotensin system inhibitors, angiotensin I-converting enzyme gene insertion/deletion polymorphism, and cancer: the Rotterdam Study

BACKGROUND: Angiotensin I-converting enzyme (ACE) inhibitors, angiotensin II antagonists, and the ACE insertion/deletion (I/D) gene polymorphism all influence serum angiotensin II action. Because angiotensin II levels have been associated with cancer, the objective of the current epidemiologic study was to investigate whether renin-angiotensin system inhibitors and/or ACE genotypes were associated with an altered risk of colorectal, lung, breast, and prostate cancer. METHODS: Data were obtained from the Rotterdam Study, a population-based, prospective cohort study with 7983 participants. Participants who had a history of 1 of the cancers of interest (n = 216) or who had a medication history <6 months (n = 88) were excluded, leaving 7679 participants, of whom the ACE genotypes could be assessed in 6670 individuals. The mean follow-up was 9.6 years, during which 730 incident cancers occurred. The effect of medication, ACE I/D genotypes, and their interaction on cancer risk and progression was studied by using Cox proportional hazard models. RESULTS: Carriers of the high-activity genotype DD had an increased risk of breast cancer compared with low-activity II/ID genotype carriers (hazard ratio [HR], 1.47; 95% confidence interval [95% CI], 1.05-2.04), but no association was demonstrated for other cancers. DD carriers who were exposed to long-term and high-dose medication were at lower risk for cancer (HR, 0.28; 95% CI, 0.10-0.79). Short-term, high-dose users were at risk for colorectal cancer progression in the II/ID stratum (HR, 3.83; 95% CI, 1.67-8.79). CONCLUSIONS: Renin-angiotensin system-inhibiting drugs seemed to protect against cancer in individuals with the DD genotype, which was associated with high levels of ACE.     

Identification of a phenanthrene derivative as a potent anticancer drug with Pim kinase inhibitory activity

Pim-3, a proto-oncogene with serine/threonine kinase activity, is aberrantly expressed in malignant lesions, but not in normal tissues, of endoderm-derived organs, including the pancreas, liver, colon, and stomach. Furthermore, the development of hepatocellular carcinoma is accelerated in mice expressing Pim-3 transgene selectively in the liver when these mice are treated with a hepatocarcinogen. These observations suggest that a chemical targeting Pim-3 kinase may be a novel type of anticancer drug. In the present study, we screened low molecular weight chemicals and observed that the phenanthrene derivative T26 potently inhibited Pim-3 and Pim-1, but only weakly inhibited Pim-2. Moreover, T26 markedly inhibited the in vitro growth of human pancreatic cancer cell lines by inducing apoptosis and G(2) /M arrest. The growth inhibitory effects of T26 were reversed by overexpression of Pim-3 cDNA in human pancreatic cancer cells, indicating that T26 acts primarily on Pim-3. Furthermore, T26 inhibited the growth of a human pancreatic cancer cell line in nude mice without causing apparent adverse effects when it was administered after tumor formation was evident. These observations imply that the chemical and its related compounds may be effective for the treatment of cancers in which there is aberrant Pim-3 expression.     

Clinical study on concentration of FT-207 and 5-FU in serum, lymph nodes and tissues after rectal administration of FT-207 suppositories for malignant diseases of the liver, biliary tract and pancreas

In order to study the antitumor effect of FT-207 in a solid tumor, it is necessary to determine the concentration of 5-FU and FT-207 in a tissue. This has only been done so far for gastric cancer and colon cancer, but these has been practically no research carried out regarding cancers of the liver, biliary tract and pancreas. A study was therefore made of lymph nodes and tissues after rectal administration of FT-207 suppositories to 12 patients with cancers of the liver, biliary tract and pancreas. These included 7 cases of pancreatic cancer, 2 cases of gall bladder cancer with infiltration to the liver, and 3 cases of hepatoma. In serum, the concentration of 5-FU reached 0.018 +/- 0.006 micrograms/ml at one hour after administration, 0.019 +/- 0.004 micrograms/ml at three hours after administration, and 0.023 +/- 0.008 micrograms/ml at six hours after administration. These concentrations would be expected to maintain a clinically sufficient dose. The concentration of 5-FU in metastatic lymph nodes was high compared with normal lymph nodes (p less than 0.05), its concentration in liver tumors was high while compared with normal liver tissues (p less than 0.05).     

Increased Midkine Gene Expression in Human Gastrointestinal Cancers

Midkine (MK) is a product of a retinoic acid-responsive gene, and is a novel growth differentiation factor. We examined the expression of the MK gene in specimens of 47 surgically removed human carcinomas of the gastrointestinal organs, namely, gastric, colorectal, hepatocellular, pancreatic, esophageal, ampullary duodenal and bile duct carcinomas. In most cases, the MK mRNA level was higher in cancer specimens than in the corresponding non-cancerous tissues. Furthermore, MK mRNA was more highly expressed in the colon adenocarcinoma lesion than in the adenoma lesions, in the two familial polyposis cases. While MK mRNA was not detected in the normal liver, it became detectable in cirrhotic tissues in 2 of 4 cases, and its expression was increased in the cancerous tissues. Thus, the increase of MK mRNA level is a phenomenon seen in many human gastrointestinal carcinomas. The increased expression of the MK gene in gastric carcinoma was significantly more prominent in well and moderately differentiated adenocarcinomas than in poorly differentiated adenocarcinomas and signet ring cell carcinomas.     

Shortened telomere length and increased telomerase activity in hamster pancreatic duct adenocarcinomas and cell lines

Recently, shortened telomere length and increased telomerase activity have been demonstrated in various human cancers. In the study reported here, we ascertained whether gene changes are characteristic of pancreatic cancers. Hamster duct carcinomas and cell lines were investigated by Southern blot analysis for telomere restriction fragment (TRF) length and by the telomeric repeat amplification protocol (TRAP) assay for telomerase activity. Comparison with normal pancreas and spleen revealed shortened TRF length and markedly increased telomerase activity in primary pancreatic duct carcinomas induced by the rapid-production model as well as in a transplantable carcinoma and the cell lines. The enzyme level was 86.0–215.7 times the low levels found in control pancreas and spleen tissues. Late-passage Syrian hamster embryo cells, known to be immortalized and tumorigenic, had shorter TRFs than the original cells in primary culture did. These results indicate that hamster pancreatic duct carcinoma cells are immortalized, with the potential for proliferation ad infinitum, and provide a model for basic therapeutic research into the substances targeting telomerase. Mol. Carcinog. 18:153–159, 1997. © 1997 Wiley-Liss, Inc.     

A new cancer-associated antigen defined by a monoclonal antibody against a synthetic carbohydrate chain

Carbohydrate antigens can be designed by referring to previously defined carbohydrate structures. We have generated a novel monoclonal antibody (MAb) (Flα-75) against an artificially designed antigen (Flα), using organic-synthetic chemistry methods and hybridoma technology. Flα (GalβI → 4GlcNAcβI → 6GalNAαI → Ser/Thr) belongs to core type 6 of O-linked glycans, which has not been previously reported in human cancers. To produce antibodies against Flα, a glycolipid was synthesized which carries the carbohydrate portion of Flα on a ceramide foundation (GalβI → 4GlcNAcβI → 6GalNAcαI → Cer). The MAbs we obtained (Flα-75, Flα-87) specifically recognized Flα and had only a very weak or no cross-reactivity with other glycolipids similar to Flα. We investigated the expression of Fin in human tissues, including 110 gastric cancers, 73 colon cancers and 42 pancreatic cancers. Flα was found in human cancerous tissues but not in normal adult tissues. The rate of positive staining with Flα-75 was 80.0% for gastric cancer, 52.4% for pancreatic cancer and 38.4% for colon cancer. Flα-75 also reacted with the tissues neighboring gastric and pancreatic tumors but not intensely. Among fetal tissues, Flα-75 reacted with the pyloric glands of the stomach, the centro-acinar cells of the pancreas, the convoluted tubules of the kidney and the terminal bronchioles of the lung.