Neuroendocrine cell differentiation of poorly differentiated colorectal adenocarcinoma correlates with liver metastasis

Poorly differentiated (PD) adenocarcinoma often retains the capacity for neuroendocrine (NE) cell differ-entiation; however, it is difficult to distinguish the NE cell differentiation by routine hematoxylin and eosin staining. It is important to detect the presence of NE cell differentiation in advanced colorectal carcinomas because these carcinomas have been shown to produce distant metastasis at the time of diagnosis and to have a particularly poor prognosis. In this study, the characteristics of PD adenocarcinoma with NE cell differentiation and its biological metastatic mechanisms were investigated. Forty-eight of 2204 colorectal cancer patients, diagnosed as having PD adenocarcinoma (2.2%) were enrolled in this study. Immunohistochemical analysis was performed with anti-chromogranin A anti-synaptophysin, anti-CD34, anti-D2-40, and anti-VEGF antibodies. The clinicopathological factors for PD adenocarcinoma with NE cell differentiation were compared with those for PD adenocarcinoma without NE cell differentiation. Microvessel density (MVD) was assessed using immunostained slides with anti-CD34 antibody and vascular endothelial growth factor (VEGF) expression in PD adenocarcinoma with NE cell differentiation was confirmed by in situ hybridization. By immunohistochemical staining for chromogranin A and synaptophysin, NE cell differentiation was detected in eight of 48 patients (16.7%) with PD adenocarcinoma. The frequency of liver metastasis at the time of diagnosis was significantly higher in patients having PD adenocarcinoma with NE cell differentiation (p=0.03). Moreover, MVD and VEGF expression level tended to be higher in patients having PD adenocarcinoma with NE cell differentiation (p=0.13 and 0.068, respectively). NE cell differentiation in PD adenocarcinoma may produce liver metastasis through microvessel formation in the tumor induced by VEGF. In PD colorectal adenocarcinoma, immunohistochemical analysis of NE markers is important for establishing the presence of NE cell differentiation and further study is necessary to evaluate the effectiveness of anti-angiogenic drugs to PD adenocarcinoma with NE cell differentiation.

Cyclooxygenase-2 expression correlates with membrane-type-1 matrix metalloproteinase expression in colorectal cancer tissue

PURPOSE

Elevated expression of cyclooxygenase-2 has been found in colorectal cancer. One of the mechanisms through which cyclooxygenase-2 affects tumorigenesis is through its overexpression, which leads to increased invasiveness of cancer cells. A crucial step in this pathway is thought to be the induction of membrane-type-1 matrix metalloproteinase, which activates matrix metalloproteinase-2. However, to date there have been few clinicopathologic studies concerning cyclooxygenase-2-mediated invasiveness in human colorectal cancer tissues.

METHODS

We performed immunohistochemical analysis of the respective antigens on colorectal cancer specimens obtained by surgical resections from 96 patients with colorectal cancer.

RESULTS

Cyclooxygenase-2 and membrane-type-1 matrix metalloproteinase expression was positive exclusively in cancer cells in 88 cases (92 percent) and 23 cases (24 percent), respectively. All 23 cases expressing membrane-type-1 matrix metalloproteinase also expressed cyclooxygenase-2. Matrix metalloproteinase-2 expression was positive in cancer cells in 20 cases (21 percent) and stromal cells in 52 cases (54 percent). Expression of matrix metalloproteinase-2 in cancer cells correlated with lymphatic invasion and local recurrence. Statistically, a significant correlation was found between cyclooxygenase-2 and membrane-type-1 matrix metalloproteinase expression, and membrane-type-1 matrix metalloproteinase and matrix metalloproteinase-2 expression in cancer cells. There was no association between cyclooxygenase-2 expression and matrix metalloproteinase-2 expression. However, immunostaining of serial sections revealed that in the majority of cases examined, nearly 100 percent of cancer cells expressing matrix metalloproteinase-2 also coexpressed cyclooxygenase-2.

CONCLUSIONS

This study indicates strong association between both cyclooxygenase-2 and membrane-type-1 matrix metalloproteinase expression, and membrane-type-1 matrix metalloproteinase and matrix metalloproteinase-2 in colorectal cancer. These results support our thesis of a direct correlation between cyclooxygenase-2 and membrane-type-1 matrix metalloproteinase expression--with consequent association between cyclooxygenase-2 and matrix metalloproteinase-2 activation, and tumor invasiveness andrecurrence in certain cases of colorectal cancer.

Preoperative oral immune-enhancing nutritional supplementation corrects TH1/TH2 imbalance in patients undergoing elective surgery for colorectal cancer

PURPOSE

Recent studies have shown that the type 1/2 CD4+ T cell (Th1/Th2) balance shifts toward Th2 dominance in cancer-bearing state or by surgical stress. Perioperative immunonutrition is reported to improve the outcome in patients with gastrointestinal cancer. This study was designed to investigate whether preoperative immunonutrition corrects the impaired Th1/Th2 balance in the perioperative period.

METHODS

Thirty-six patients with colorectal cancer were prospectively divided into two groups as follows: preoperative oral intake supplementation with a formula enriched with arginine, omega-3 fatty acids and ribonucleic acid for five days (supplemented group; n = 19); and (control group; n = 17). Blood sampling was performed before supplementation, on the morning of surgery, and 3, 7, and 14 days postoperatively. The proportions of CD4+ T cells producing intracellular cytokines (interferon-gamma and interleukin-4) were measured by flow cytometry.

RESULTS

In the preoperative period, the proportions of CD4+ T cells producing interleukin-4 significantly decreased and Th1/Th2 ratio significantly increased on the morning of surgery compared with those before supplementation. In the postoperative period, the proportions of CD4+ T cells producing interferon-gamma in both groups maintained the preoperative level. The proportions of CD4+ T cells producing interleukin-4 in the control group showed a gradual increase from the preoperative level, which implies Th2 dominant shift. In contrast, the supplemented group maintained the preoperative level of Th1/Th2 ratio.

CONCLUSIONS

Preoperative immunonutrition corrects impaired Th1/Th2 balance in both cancer-bearing state and the postoperative period. This correction may be one of the important determinants of the clinical benefits of immunonutrition.

Ubiquitin-specific protease 14 expression in colorectal cancer is associated with liver and lymph node metastases

Ubiquitin-specific protease 14, also known as the 60 kDa subunit of tRNA-guanine transglycosylase (USP14/TGT60 kD), belongs to the ubiquitin-specific processing protease (UBP) family. USP14/TGT60 kD expression in leukemic and colorectal cancer cell lines, and the suppression of such an expression after the induction of cell differentiation have been reported. In the present study, we attempted to clarify whether USP14/TGT60 kD overexpression affects the clinicopathological features of colorectal cancer. Immunohistochemically, USP14/TGT60 kD was absent or weakly localized in the cytoplasm of normal colorectal epithelial cells. In 18 of 99 (18.2%) colorectal cancer patients, USP14/TGT60 kD was strongly detected in the cytoplasm of cancer cells. USP14/TGT60 kD expression correlated with pathological stage (P=0.03), and lymph node (P=0.03) and liver (P=0.03) metastases. Furthermore, the percentage of patients strongly positive for USP14/TGT60 kD expression increased with pathological stage. The overall survival rate was worse in patients with a high USP14/TGT60 kD expression level than in those with a low USP14/TGT60 kD expression level. Our results suggest that USP14/TGT60 kD also controls the fate of proteins that regulate tumor invasion and metastasis.

Different expression levels of lumican in human carcinoid tumor and neuroendocrine cell carcinoma

Lumican is a member of the small leucine-rich proteoglycan (SLRP) family and participates in the maintenance of tissue structures and tumor growth. Neuroendocrine cell tumors (NETs) including carcinoid tumors and NE cell carcinomas (NECs) possess numerous neuroendocrine (NE) granules, and differences between these tumors are in terms of their biological and metastatic aggressiveness during tumor progression. The purpose of this study was to examine the expression of lumican in NETs, and to determine whether the presence of lumican may be associated with the growth of NETs by comparing its expression between carcinoid tumors and NECs. Immunohistochemically, the positivity rates of lumican expression in the cytoplasm of the tumor cells were 87.5% in carcinoid tumors and 37.5% in NECs. Those of lumican expression in the stroma adjacent to the tumors were 90.1% in carcinoid tumors and 79.2% in NECs. In situ hybridization analysis revealed the lumican mRNA expression in the cytoplasm of carcinoid tumor and NEC cells. Ultrastructurally, the lumican protein was observed in the rough endoplasmic reticulum and NE granules of NETs and interspaces of collagen fibers. Furthermore, RT-PCR analysis revealed the presence of lumican mRNA in NEC cell lines. These results indicate that the higher expression level of cytoplasmic lumican in carcinoid tumors than in NECs may play a role in the slow growth of these tumors.

Correlation of hypoxia inducible factor-1alpha with lymphatic metastasis via vascular endothelial growth factor-C in human esophageal cancer

Hypoxia inducible factor (HIF)-1alpha is a transcription factor that regulates the transcription of genes associated with cell proliferation and vascular development. In various cancer tissues, HIF-1alpha is associated with clinicopathological factors, such as the tumor size, histological grade, and lymph node status. Although HIF-1alpha plays a critical role in tumor growth by inducing vascular endothelial growth factor (VEGF), it is unclarified whether HIF-1alpha affects lymphatic metastasis. The purpose of this study is to clarify the correlation of HIF-1alpha protein expression with lymph node metastasis in esophageal squamous cell carcinoma (ESCC). The expressions of HIF-1alpha and VEGF-C, which is one of the main lymphangiogenic factors, were examined in five ESCC cell lines and 48 surgical specimens of ESCC. HIF-1alpha and VEGF-C mRNAs were expressed in all the five ESCC cell lines as determined by RT-PCR analysis. Immunohistochemically, 34 of the 48 patients (70.8%) were positive for HIF-1alpha and 29 patients (60.4%) were positive for VEGF-C. Clinicopathologically, HIF-1alpha expression correlated with lymphatic invasion and VEGF-C expression (P = 0.003 and P = 0.01, respectively). Furthermore, HIF-1alpha expression tended to correlate with lymph node metastasis (P = 0.09). These findings suggest that HIF-1alpha plays a role in lymphatic invasion and lymph node metastasis through the induction of VEGF-C in ESCC.

The Role of Transanal Endoscopic Microsurgery for Rectal Tumors

PURPOSE

The management of rectal tumors is complex, because of the balance between preserving rectoanal function and curing the patient. Transanal endoscopic microsurgery (TEM) is both an effective treatment for benign rectal tumors and early cancers, and a diagnostic tool for determining tumor depth, or for residual tumors of post endoscopic mucosal resection. In the present study, we evaluated the role of TEM in the management of rectal tumors.

METHODS

Twenty-six patients with rectal tumors underwent TEM from December 2000 through March 2005 in our department. The operations were performed by a single surgeon, and the indications were mainly limited to a) benign tumors for which endoscopic resection was difficult, b) early cancers that had invaded the submucosa within 500 microm of the muscularis mucosae, c) submucosal tumors, i.e., gastrointestinal stromal tumor, carcinoid tumors, d) local excision for diagnosis, and e) palliative resection for high-risk cases. Anesthesia, operation time, sizes of the tumor and of resected specimens, postoperative complications, length of hospitalization, pathological results, and postoperative recurrence rate were reviewed.

RESULTS

The mean age of patients was 61.9 years, and the cases included 14 rectal cancers, 7 adenomas, 1 gastrointestinal stromal tumor, and 3 rectal carcinoid tumors. The mean operation time was 96 min (range, 40 approximately 235 min.). The average postoperative hospital stay was 4.8 days. All tumors were resected with horizontal and vertical safety margin. The mean size of the resected specimens was 9.0 cm(2). In one case, the tumor had infiltrated the proper muscle layer, as shown by intraoperative frozen sectioning, which necessitated abdominoperineal resection. In 3 cases, pathological examination revealed massive infiltration into the submucosal layer. 2 patients underwent low anterior resection, and the remaining patient refused additional surgery despite our recommendation. No deaths occurred. No major postoperative complications were noted. The mean follow-up period was 27.2 months. Only one case of lymph node metastasis was observed, in the left iliac lymph node 3 years after TEM.

CONCLUSIONS

TEM is a minimally invasive surgical procedure for rectal tumors, which allows the whole depth of the rectal wall to be resected with a safety surgical margin. Although TEM requires technical skill and accurate preoperative diagnosis, the procedure is safe, facilitates accurate diagnosis of tumor depth, and limits the need for additional surgery.

A case report of duodenal carcinoid tumor associated with early gastric cancer

A rare case of carcinoid tumor in the duodenal bulb associated with early gastric carcinoma is reported. An 85-year-old asymptomatic male was admitted to our hospital, referred by his neighboring doctor because of early gastric carcinoma shown by endoscopic examination. X-ray studies of the upper gastrointestinal tract showed irregular lesser curvature of the gastric antrum and a filling defect (phi1 cm) at the duodenal bulb. Gastric biopsy revealed the histological findings of Group V. Distal gastrectomy including the duodenal bulb with D2 lymph node dissection was performed. A resected specimens showed superficial depressed type carcinoma at the lesser curvature of the antrum, and an isolated submucosal tumor of 7x7 mm in size at the duodenal bulb. Histological examination disclosed papillary adenocarcinoma in the gastric mucosa and a carcinoid tumor of the duodenal bulb in the submucosal layer without high malignant findings. The patient has been well for 5 years since the surgery. In conclusion, we discussed 46 collected cases of carcinoid tumor of the duodenum associated with gastric carcinoma in Japan. Preoperative diagnosis of carcinoid tumor of the duodenum is very difficult, and thorough examinations are needed for submucosal lesion.

External Whole-body Image of EGFP Gene Expression

Whole-body optical imaging is an external and noninvasive procedure that enables the continuous visual monitoring of malignant growth and spread within intact animals. The human colon adenocarcinoma cell-line HCT-15 was transfected with a pIRES 2-EGFP vector, and stable enhanced green fluorescence protein (EGFP) expression was established (Fig.1). Approximately 10(6) HCT-15 EGFP stable transfectant cells were subcutaneously injected into the left flank of six-week-old male Balb/c-nu/nu mice. On post-injection day 78, the size of the subcutaneous tumor was 13.1 mm x 15.4 mm in diameter, as observed using an ORCA-C 7780-20 three-chip cooled color charge-coupled-device camera (Hamamatsu Photonics Systems, Hamamatsu City, Japan). An external fluorescent image of the tumor was acquired through the skin (Fig.2B). The tumor could be seen more clearly once the skin was removed (Fig.2D). Furthermore, in the peritoneal metastasis (Fig.3B) and liver metastasis models (Fig.3D), metastasis could also be seen through the skin. This new technology is a useful method for investigating tumor growth in vivo. In the future, this method could be applied to the detection of peritoneal, liver and lung metastasis in living animals.