Biology of human colon cancer metastasis

Role of non-coding RNAs as novel biomarkers for detection of colorectal cancer progression through interaction with the cell signaling pathways

Colorectal cancer (CRC) is one of the most common types of cancer which affects the colon and the rectum. Approximately one third of annual CRC mortality occurs due to the late detection of this type of cancer. Therefore, there is an urgent need for more powerful diagnostic and prognostic tools for identification and treatment of colorectal tumorigenesis. Non-coding RNAs (ncRNAs) have been implicated in the pathology of CRC and also linked to metastasis, proliferation, differentiation, migration, angiogenesis and apoptosis in numerous cancers. Recently, attention has turned towards ncRNAs as specific targets for diagnosis, prognosis and treatment of various types of cancers, including CRC. In this review, we have tried to outline the roles of ncRNAs, and their involvement in signaling pathways responsible for the progression of CRC.

Patient-Derived Orthotopic Xenograft models in gastric cancer: a systematic review

Patient-Derived Xenografts (PDXs) are, so far, the best preclinical model to validate targets and predictors of response to therapy. While subcutaneous implantation very rarely allows metastatic dissemination, orthotopic implantation (Patient-Derived Orthotopic Xenograft-PDOX) increases metastatic capability. Using a modified tool to analyze model validity, we performed a systematic review of Embase, PubMed, and Web of Science up to December 2018 to identify all original publications describing gastric cancer (GC) PDOXs. We identified ten studies of PDOX model validation from January 1981 to December 2018 that fulfilled the inclusion and exclusion criteria. Most models (70%) were derived from human GC cell lines rather than tissue fragments. In 90% of studies, the implantation was performed in the subserosal layer. Tumour engraftment rate ranged from 0 to 100%, despite the technique. Metastases were observed in 40% of PDOX models implanted into the subserosal layer, employing either cell suspension or cell line-derived tumour fragments. According to our modified model validity tool, half of the studies were defined as unclear because one or more validation criteria were not reported. Available GC PDOX models are not adequate according to our model validity tool. There is no demonstration that the submucosal site is more effective than the subserosal layer, and that tissue fragments are better than cell suspensions for successful engraftment and metastatic spread. Further studies should strictly employ model validity tools and large samples with orthotopic implant sites mirroring as much as possible the donor tumour characteristics.

Aerial Parts of Peucedanum chenur Have Anti-Cancer Properties through the Induction of Apoptosis and Inhibition of Invasion in Human Colorectal Cancer Cells

Background:

The Peucedanum species have many pharmacological effects due to the presence of coumarins, flavonoids, phenolic compounds, and essential fatty acids in these species. In this study, for the first time, the anticancer activity of Peucedanum chenur methanolic extract via the induction of apoptosis and inhibition of invasion in HCT-116 human colon cancer cells was investigated.

Methods:

P. chenur methanolic extract effect on HCT-116 cells viability and antioxidant activity were evaluated using MTT assay, DPPH, and iron chelating tests, respectively. Changes in mRNA expression level in a panel of relevant genes were assessed by the quantitative real-time PCR. Also, apoptosis was assessed by cell cycle analysis and Annexin V/PI method, and the effect on cell migration was tested using scratch test.

Results:

P. chenur methanolic extract increased significantly the expression of BAX while decreased the expression of BCL-2, AKT1, FAK, RhoA, and MMP genes compared to the control group. BAX/BCL-2 ratio and apoptosis elevated, whereas cell migration reduced significantly. Besides, our extract showed an appropriate antioxidant activity.

Conclusion:

P. chenur may be introduced as a new chemopreventive agent in medicine due to its notable power in terms of induction of apoptosis and inhibition of invasion.

Multidisciplinary Diagnostic and Surgical Management of Adenocarcinoma Gingival Metastases

Colon cancer is the third leading cause of cancer-related mortality worldwide and colon cancer metastases in rare sites, such as the oral cavity, lead to a worse prognosis. Oral metastasis is a rare clinical condition and it represents only the 1% among all oral cavity neoplasms. A multidisciplinary approach is recommended to carry out a correct diagnostic procedure that allows distinguishing between metastatic and primitive lesions of the oral cavity. Quick diagnosis and management are fundamental to take an appropriate action as early as possible, as usually the prognosis in patients with oral metastases of colon carcinoma is poor. Aim of this brief clinical report is to underline how the quick diagnosis and management of gingival lesions can be crucial for the correct management of those uncommon oral diseases and for having a better prognosis of the primary cancer.

Identification of endothelial selectin as a potential prognostic marker in breast cancer

Endothelial selectin (ELAM1 or CD62E) has been previously reported as being associated with the prognosis of multiple types of cancer. However, its prognostic value in breast cancer (BC) remains unclear. The aim of the present study was to investigate the prognostic value of ELAM1 mRNA expression in BC tissue. The prognostic value of ELAM1 mRNA was assessed in patients with BC using the Kaplan-Meier plotter (KM-plot) database. The KM-plot generated updated ELAM1 mRNA expression data and survival analysis from a total of 3,951 patients with BC, gathered from 35 datasets. Low expression of ELAM1 mRNA was correlated with a poorer overall survival in 1,402 patients with BC followed for 20 years [hazard ratio (HR), 0.71; 95% confidence interval (CI), 0.57–0.88; log-rank P=0.0016]. Low expression of ELAM1 was also correlated with poorer relapse-free survival (HR, 0.69; 95% CI, 0.62–0.77; log-rank P=2.2e-11) in 3,951 patients and poorer distant metastasis-free survival (HR, 0.79; 95% CI, 0.65–0.96; log-rank P=0.02) in 1,746 patients with BC followed for 20 years. Results from the Metabolic gEne RApid visualizer database indicated that ELAM1 mRNA expression was elevated in normal tissue. The results of the present study suggest that ELAM1 mRNA is a potential prognostic and metastatic marker in patients with BC.

Colon cancer metastasis to the mandibular gingiva with partial occult squamous differentiation: A case report and literature review

Metastasis is the primary cause of death among patients with colon cancer. However, the number of available studies regarding oral cavity metastases from colon cancer is currently limited. We herein report an unusual case of a 60-year-old male patient who developed an oral cavity metastasis from colon cancer. A total of 12 clinical case studies reporting colon cancer metastases to the mandibular gingival region were also reviewed, with the aim to elucidate the clinical and pathological characteristics of this disease entity in order to improve clinical diagnosis and treatment. It was demonstrated that patients with oral cavity metastases from colon cancer were predominantly in the sixth or seventh decades of life. The mandible was the main site of metastatic tumors to the oral cavity, while the occurrence of gingival metastases was comparatively rare. Moreover, the diagnoses of an oral metastatic tumor and primary colon cancer were often synchronous and were frequently accompanied with metastases to other organs. Several key aspects were suggested that should be accounted for when diagnosing colon cancer patients, including focusing attention to oral symptoms when examining cancer patients, utilizing a multidisciplinary approach for differential diagnosis and utilizing postoperative pathological examination to accurately diagnose the type of tumor and optimize the efficacy of treatment.

Prognostic risk factors in patients with bone metastasis from colorectal cancer

The morbidity of bone metastasis (BM) from colorectal cancer (CRC) is increasing more than ever; however, insufficient research on BM from CRC leads to reduced awareness of the issue. Therefore, the aim of this study was to evaluate the clinical features and prognostic risk factors of CRC patients with BM. Clinical data were retrospectively analyzed for a total of 242 CRC patients with BM. Of the 242 CRC patients with BM, 52 (21.5 %) had bone metastasis alone (BMA) and 190 (78.5 %) had both bone and visceral metastasis (BM&VM). The median survival time (MST) after the diagnosis of BM in all 242 patients was 15.6 months (95 % confidence interval [CI] 12.74-18.46 months). The MST of the BMA group was significantly longer than that of the BM&VM group (29.1 vs. 12.8 months, p = 0.003). Using a Cox proportional hazard model, we identified a high carcinoembryonic antigen (CEA) level and BMA as independent prognostic factors for CRC patients with BM. For the BMA group, the independent prognostic factors were elevated alkaline phosphatase (ALP) and perineural invasion of the primary cancer, which were distinct from the factors for the entire group of BM patients. Furthermore, we found that the BMA patients with multiple sites of BM had similar prognosis to the BM&VM patients. These findings together provide us with a further understanding of BM from CRC and reveal that BMA may be a distinct subset of BM from CRC that has unique independent prognostic factors and a good prognosis.

The role of microRNAs in colorectal cancer

Colorectal cancer (CRC) is still the third most common cancer in the world. Mechanism of CRC tumorigenesis has been widely studied at the molecular levels, and has been recently entered the area of microRNAs. MicroRNAs are small 19 to 22 nucleotides of RNA that engage in the regulation of cell differentiation, apoptosis, and cell cycle progression. MicroRNAs are similar to small interfering RNA (siRNA), that post-transcriptionally regulate gene expression and control various cellular mechanisms. They are important factors in the carcinogenesis of CRC, one of the most important factors includes microRNA. MicroRNAs have been linked to CRC development, and these molecules have been recently studied as new potential biomarkers in diagnosis and treatment of CRC. Specific microRNA expression patterns help distinguish CRC from other colon related disease, and may be used as a prognostication factor in patients after treatment with different chemotherapy drugs. More over the newest molecular therapy via tumor suppressor micro RNA replacement can be new insight in molecular therapy of CRC. This review summarizes the potential roles of microRNAs as potential biomarkers for CRC diagnosis, and treatment.

Gallic acid induced apoptotic events in HCT-15 colon cancer cells

AIM: To investigate the inhibitory action of diet-derived phenolic compound gallic acid (GA) against HCT-15 colon cancer cells.

METHODS: The antiproliferative effect of GA against colon cancer cells was determined by performing thiazolyl blue tetrazolium bromide (MTT) assay. The colony forming ability of GA treated colon cancer cells was evaluated using the colony forming assay. The cell cycle changes induced by GA in HCT-15 cells were analyzed by propidium iodide staining. Levels of reactive oxygen species (ROS) and mitochondrial membrane potential of HCT-15 exposed to GA was assessed using 2’,7’-dichlorfluorescein-diacetate and rhodamine-123 respectively, with the help of flow cytometry. Morphological changes caused by GA treatment in the colon cancer cells were identified by scanning electron microscope and photomicrograph examination. Apoptosis was confirmed using flow cytometric analysis of GA treated HCT-15 cells after staining with Yo-Pro-1.

RESULTS: MTT assay results illustrated that GA has an inhibitory effect on HCT-15 cells with IC₅₀ value of 740 μmol/L. A time-dependent inhibition of colony formation was evident with GA treatment. Cell cycle arrest was evident from the accumulation of GA treated HCT-15 cells at sub-G1 phase (0.98 ± 1.03 vs 58.01 ± 2.05) with increasing exposure time. Flow cytometric analysis of GA treated HCT-15 cells depicted early events associated with apoptosis like lipid layer breakage and fall in mitochondrial membrane potential apart from an increase in the generation of ROS which were in a time dependent manner. SEM and photomicrograph images of the GA-treated cells displayed membrane blebbing and cell shrinking characteristics of apoptosis. Further apoptosis confirmation by Yo-Pro-1 staining also showed the time-dependent increase of apoptotic cells after treatment.

CONCLUSION: These results show that GA induced ROS dependent apoptosis and inhibited the growth of colon cancer cells.

Effects of autophagy regulation of tumor-associated macrophages on radiosensitivity of colorectal cancer cells

Tumor‑associated macrophages (TAMs), a major component of the tumor microenvironment, are crucial to the processes of tumor growth, infiltration and metastasis, and contribute to drug resistance. The importance of TAMs in radiation resistance of colorectal cancer remains unclear. To investigate the effects of autophagy regulation of TAMs on the radiosensitivity of colorectal cancer cells, the current study induced TAM formation from THP‑1 monocyte cells. Sequential treatment of THP‑1 cells with PMA for 72 h and human recombinant interleukin‑4 for 24 h was used to stimulate THP‑1 differentiation to TAMs. Expression of the cell surface markers CD68, CD204 and CD206, and changes to cell morphology were used to confirm successful differentiation. The TAMs were stimulated to promote or inhibit autophagy during co‑culture with LoVo colorectal adenocarcinoma cells. The cells were irradiated, with subsequent measurement of LoVo colony formation and apoptosis. Additionally, the expression of p53, Bcl‑2, survivin and Smac proteins was assessed by western blotting. Monodansylcadaverin staining was used to analyze the presence of autophagic vacuoles in TAM, and western blot analysis was used to assess the expression of Beclin‑1, LC3B I and II, ATG‑3, ‑5 and ‑7. The results demonstrated TAM autophagy to be markedly altered by rapamycin and bafilomycin A1 treatment. Following co‑culture with TAMs, the colony formation rate and survival fraction of LoVo cells were significantly higher than those in the control group (P<0.05). It was further demonstrated that the regulation of autophagy in TAMs was able to inhibit the colony formation of LoVo colorectal cancer cells. Upregulation of TAM autophagy using rapamycin exhibited more effective inhibition of LoVo colony formation than autophagy downregulation. Notably, apoptosis was significantly increased in LoVo cells when co‑cultured with TAMs only, or with rapamycin‑mediated autophagy upregulated TAMs, compared with LoVo cells cultured alone (P<0.01). Expression of Bcl‑2, survivin and p53 were reduced in LoVo cells co‑cultured with TAMs, compared with the control group (P<0.05), whereas Smac expression was increased in the co‑culture groups (P<0.01). It was demonstrated that rapamycin‑mediated autophagy stimulation in TAMs led to reduced expression levels of survivin and Bcl‑2, however, Smac expression was increased. The upregulation of autophagy in TAMs inhibited proliferation and induced apoptosis in colon cancer cells, and altered the expression of radiosensitivity‑associated proteins. This data indicated that the radiosensitivity of colorectal cancer cells is associated with autophagy of TAM, and that stimulating TAM autophagy may increase the radiosensitivity of colorectal cancer cells.

Prognostic factors for patients with stage II colon cancer: results of a prospective study

PURPOSE

Many studies revealed that the recurrence rate of stage II colon cancer was up to 25–40 %. Regrettably, the risk factors for recurrence of stage II colon cancer remain ambiguous. So, we conducted this study to identify the clinicopathological factors associated with prognosis of stage II colon cancer.

METHODS

We enrolled 452 stage II colon cancer patients who underwent radical resection at Peking University Cancer Hospital between January 2007 and December 2010, and 162 patients who received adjuvant treatment were excluded.

RESULTS

The 5-year recurrence rate and overall survival of this cohort were 19.3 (56/290) and 75.9 % (220/290), respectively. In univariate analysis, the following variables were significantly associated with tumor recurrence:male patients (P<0.001), tumor size >5 cm (P=0.048), and preoperative carcinoembryonic antigen (CEA) level ≥ 5 ng/ml (P=0.004); the following factors were significantly associated with adverse 5-year overall survival:male patients (P<0.001), age ≥60 years old (P=0.004), less than 12 lymph nodes (P=0.006), and preoperative CEA level ≥5 ng/ml (P=0.011). In multivariate analysis,the preoperative CEA level ≥5 ng/ml (P=0.003) and male (P<0.001) were adverse variables significantly associated with tumor recurrence, and the preoperative CEA level ≥ 5 ng/ml (P=0.016), male (P<0.001), and age ≥60 years old (P=0.008) were independent prognostic factors for the 5-year overall survival rate, respectively.

CONCLUSIONS

The preoperative CEA level ≥5 ng/ml and male were undesirable factors significantly associated with tumor recurrence. The preoperative CEA level ≥5 ng/ml, male, and age ≥60 years old were adverse factors significantly associated with poor prognosis.

Minimally invasive colorectal resection is associated with significantly elevated levels of plasma matrix metalloproteinase 3 (MMP-3) during the first month after surgery which may promote the growth of residual metastases

INTRODUCTION

MMP-3, a member of the matrix metalloproteinase (MMP) family, is involved in the breakdown of the extracellular matrix in tissue remodeling and may also play a role in cancer progression and metastasis. Minimally invasive colorectal resection (MICR) may increase plasma MMP-3 levels directly via surgical trauma or indirectly due to surgery-associated elevations in TNF-α and IL1 which are regulators of MMP-3. This study's purpose was to evaluate plasma MMP-3 levels during the first month after MICR for colorectal cancer.

METHODS

Patients enrolled in an IRB approved data/plasma bank who underwent elective MICR for CRC. Blood plasma samples had been collected preoperatively, on postoperative day (POD) 1, 3 and at varying postoperative time points and were stored at -80 °C. The late samples (POD 7-41) were bundled into 7 day time blocks and considered as single time points. MMP-3 levels were analyzed in duplicate via ELISA and the results reported as mean ± SD. The paired t test was used for analysis (significance, p < 0.008 after Bonferroni's correction).

RESULTS

A total of 73 CRC patients who underwent MICR met the inclusion criteria. The mean PreOp MMP-3 level was 14.9 ± 7.8 ng/ml (n = 73). Significantly elevated mean plasma levels were noted on POD 1 (21.4 ± 14.7 ng/ml, n = 73, p < 0.0001), POD 3 (37.9 ± 21.5 ng/ml, n = 72, p < 0.0001), POD 7-13 (22.0 ± 13.0 ng/ml, n = 56, p < 0.0001), POD 14-20 (21.9 ± 10.3 ng/ml, n = 20, p = 0.003), and on POD 21-27 (21.9 ± 11.43 ng/ml, n = 20, p = 0.002) when compared to PreOp levels. Plasma levels returned to the PreOp baseline at the POD 28-41 time point (n = 16, p = 0.07).

CONCLUSION

Plasma MMP-3 levels remained significantly elevated from baseline for 4 weeks after MICR for CRC. The early postoperative increase in MMP-3 levels may be due to the surgery-related acute inflammatory response; the elevation noted during weeks 2-3 may be related to wound healing. Increased MMP-3 levels may promote metastases or the growth of residual cancer.

Pulmonary metastasectomy for colorectal cancer: How many nodules, how many times?

Colorectal cancer (CRC) is one of the most common cancers worldwide, with 5%-15% of CRC patients eventually developing lung metastasis (LM). Despite doubts about the role of locoregional therapy in the management of systemic disease, many surgeons have performed pulmonary metastasectomy (PM) for CRC in properly selected patients. However, the use of pulmonary metastasectomy remains controversial due to the lack of randomized controlled studies. This article reviews the results of surgical treatment of pulmonary metastases for CRC, focusing on (1) current treatment guidelines and surgical techniques of PM in patients with LM from CRC; (2) outcomes of PM and its prognostic factors; and (3) controversial issues in PM, focusing on repeated metastasectomy, bilateral multiple metastases, and combined liver and lung metastasectomy.

Incidence and predictive factors for pulmonary metastases after curative resection of colon cancer

PURPOSE

To assess the actuarial incidence of pulmonary metastases as the first site of metastasis after R0 resection of colon cancer and to clarify predictive factors for pulmonary metastases as the first site of metastasis.

METHODS

Data for 746 patients who underwent R0 resection for colon cancer from 2000 to 2006 were reviewed. The mean duration of follow-up was 56.9 months.

RESULTS

Pulmonary metastases developed in 35 patients. Mean duration from colon surgery to identification of pulmonary metastases was 20.0 months. The overall occurrence rates of 5-year pulmonary metastasis according to Union for International Cancer Control (UICC) stage were 0.6 % (stage I), 2.2 % (stage II), 9.8 % (stage III), and 24.6 % (stage IV), respectively. Surgery for pulmonary metastases was performed first 18 patients (51.4 %), and 16 (88.9 %) of these 18 patients achieved R0 surgery. Multivariate analysis revealed that presence of regional lymph node involvement and preoperative serum carcinoembryonic antigen level (≥5 ng/ml) were significant independent risk factors for pulmonary metastases. Five-year actuarial incidence of pulmonary metastases increased significantly with increased number of risk factors (0 factors, 2.2 %; 1 factor, 6.6 %; 2 factors, 18.4 %).

CONCLUSIONS

The present study clearly demonstrated predictive factors for pulmonary metastases after R0 resection of colon cancer. Actuarial incidence of pulmonary metastases was significantly related to the number of risk factors present. The data should facilitate the establishment of novel algorithms for predicting pulmonary metastases after resection of colon cancer, which may lead to the appropriate surveillance strategies after colon surgery.

Tube-like structures with co-expression of D2-40 and CD34: newly formed vasculatures?

Background: A great number of in vitro and in vivo studies have suggested that many pathways or factors can stimulate angiogenesis and lymphangiogenesis, which facilitate tumor progression and metastasis. However, the morphological and immunohistochemical profile of newly formed vasculatures has not been elucidated, making it difficult to differentiate them from the pre-existing ones, and to identify their unique molecular profiles for diagnosis and therapeutic interventions.

Experimental findings: As cytokeratin (CK)-19 is a well-recognized stem cell marker and CK-19-positive cells are frequently detected in the peripheral blood of patients with metastatic cancer, our recent studies have assessed the involvement of CK-19 in the formation of new vasculatures in primary colorectal cancer (CRC) tissues. Our studies showed that a subset of lymph node-positive cases harbored some isolated normal epithelial structures with distinct CK-19 immunostaining within an otherwise CK-19-negative background. These structures are exclusively located within or adjacent to lymphoid follicles and are often surrounded by tube-like structures expressing lymphatic endothelial marker D2-40. Similar structures are more frequently seen at the junctions between pre-invasive and invasive CRC with the following features: (1). they consist of a single layer of endothelial cells that express both D2-40 and CD34, (2). their endothelial walls are often incomplete with disseminated cells protruding into the adjacent stroma, and (3). they are exclusively associated with disseminated CK-19-positive cells

Hypothesis: Based on these findings, we propose that these tube-like structures represent newly formed vasculatures, which are derived by the convergence of aberrant lymphocyte infiltration and tumor stem cells. Because of their close physical proximity, tumor stem cells within the epithelial and stromal components contribute equally and coordinately to the morphogenesis of new vasculatures, which constitutes the basis for the unique morphologic and immunohistochemical features of newly formed vasculatures. Our hypothesis appears to be applicable to all epithelium-derived cancers.

Novel anti-angiogenic effects of formononetin in human colon cancer cells and tumor xenograft

Formononetin is a novel herbal isoflavonoid isolated from Astragalus membranaceus, a medicinal plant that possesses antitumorigenic properties. Our previous findings demonstrated that formononetin initiates growth-inhibitory and pro-apoptotic activities in human colon cancer cells. In the present study, we aimed to further examine the potential of formononetin in controlling angiogenesis and tumor cell invasiveness in human colon cancer cells and tumor xenografts. The results showed that formononetin downregulated the expression of the key pro-angiogenic factors, including vascular endothelial growth factor (VEGF) and matrix metalloproteinases. We also discovered that the invasiveness of metastatic colon cancer cells was alleviated following drug treatment. The potential anti-angiogenic effect of formononetin was examined in nude mouse xenografts. The tumor size and the number of proliferating cells were reduced in the tumor tissues obtained from the formononetin-treated group. The serum VEGF level was also reduced in the drug-treated animals when compared to the controls. These findings suggest that formononetin inhibits angiogenesis and tumor cell invasion, and thus support its use in the treatment of advanced and metastatic colon cancers.

Colorectal cancer and thoracic surgeons: close encounters of the third kind

Resection of lung metastases from colorectal cancer (CRC) is increasingly performed with a curative intent. This strategy was made possible in the 1990s by the development of new chemotherapeutic approaches, improved surgical techniques and better imaging modalities. However, evidence-based data showing clinical benefits of lung metastasectomy in this setting are nonexistent, and there are no prospective randomized trials to support the routine performance of these procedures for stage IV CRC. Current evidence suggests that resection of pulmonary metastases in combination with new cytotoxic agents, such as oxaliplatin, irinotecan and bevacizumab, may result in prolonged survival for many, and cure for a small minority of CRC patients who experienced tumor spread beyond the limits of the abdomen. This review focuses on the results of surgical management of CRC patients with lung metastases: we report the outcome of published series according to the presence or the absence of liver metastasis (and hepatic resection) prior to lung resection.

Brain metastases from colorectal cancer: the role of surgical resection in selected patients

AIM

Brain metastasis is infrequent in colorectal cancer patients, and the prognosis is poor. In this retrospective study survival and prognostic factors were determined in patients with brain metastasis from colorectal cancer.

METHOD

Between 1997 and 2006, 39 patients with brain metastasis from colorectal cancer who survived more than 1 month were identified. Data were collected with regard to patient characteristics, location and stage of the primary tumour, extent and location of metastatic disease, and treatment modalities used.

RESULTS

Most (79.5%) patients had pulmonary metastases before brain metastasis, and the brain was the site of solitary metastasis in only one patient. The most frequent symptom was weakness [18 (43.6%) patients]. Overall median survival was 5.0 months and the 1- and 2-year survival rates were 21.8 and 9.1%, respectively. Univariate analysis revealed uncontrolled extracranial metastases (P = 0.019), multiple brain lesions (P = 0.026), bilateral brain metastases (P = 0.032) and serum carcinoembryonic antigen levels greater than 5 ng/ml (P = 0.008) to be poor prognostic factors. The median survival after the diagnosis of brain metastasis was significantly longer in patients who underwent surgical resection (15.2 ± 8.0 months) than in those treated by other modalities (P = 0.001). Treatment modality was the only independent prognostic factor for overall survival in patients with brain metastases from colorectal cancers (P = 0.015).

CONCLUSION

Aggressive surgical resection in selected patients with brain metastases from colorectal cancer may prolong survival, even in the presence of extracranial metastatic lesions.

Plasma soluble vascular adhesion molecule-1 levels are persistently elevated during the first month after colorectal cancer resection

INTRODUCTION

Plasma from the second and third weeks after minimally invasive colorectal resection (MICR) has high levels of the proangiogenic proteins VEGF and angiopoietin 2 and also stimulates, in vitro, endothelial cell (EC) proliferation and migration, which are critical to wound and tumor angiogenesis. Soluble vascular cell adhesion molecule-1 (sVCAM-1) stimulates EC chemotaxis and angiogenesis. The impact of MICR on blood levels of sVCAM-1 is unknown. This study's purpose was to determine plasma sVCAM-1 levels after MICR in colorectal cancer (CRC) patients.

METHODS

Blood samples from 90 patients (26% rectal, 74% colon) were obtained preoperatively, on postoperative days (POD) 1 and 3, and at other points during the next 2 months. The late samples were bundled into 7-day time blocks. sVCAM-1 levels were determined in duplicate via ELISA and reported as ng/ml. Student's t test was used for data analysis (significance, P < 0.008 after Bonferroni correction).

RESULTS

The mean incision length was 7.3 ± 3.1 cm, and the conversion rate was 3%. Compared with preoperative (PreOp) levels (811.3 ± 233.2), the mean plasma sVCAM-1 level was significantly higher on POD 1 (905.7 ± 292.4, P < 0.001) and POD 3 (977.7 ± 271.8, P < 0.001). Levels remained significantly elevated for the POD 7-13, POD 14-20, POD 21-27, and POD 28-67 time blocks.

CONCLUSIONS

MICR for CRC is associated with a persistent increase in plasma sVCAM-1 levels during the first month. This sustained increase may promote angiogenesis and stimulate the growth of residual tumor cells early after surgery.

Implications of microRNAs in colorectal cancer development, diagnosis, prognosis, and therapeutics

MicroRNAs (miRNAs) are a class of non-coding small RNAs with critical regulatory functions as post-transcriptional regulators. Due to the fundamental importance and broad impact of miRNAs on multiple genes and pathways, dysregulated miRNAs have been associated with human diseases, including cancer. Colorectal cancer (CRC) is among the most deadly diseases, and miRNAs offer a new frontier for target discovery and novel biomarkers for both diagnosis and prognosis. In this review, we summarize the recent advancement of miRNA research in CRC, in particular, the roles of miRNAs in CRC stem cells, epithelial-to-mesenchymal transition, chemoresistance, therapeutics, diagnosis, and prognosis.

Surgical resection for lung metastases from colorectal cancer

PURPOSE

The lung is the second most common site of metastasis from colorectal cancer. Of all patients who undergo a curative resection for colorectal cancer, 10% to 15% will develop lung metastasis. As a hepatic resection of colorectal liver metastases results in improved survival, many reports have suggested that a pulmonary resection of a colorectal lung metastasis would also improve survival. The aim of this study was to analyze the postoperative outcomes of and the prognostic factors for a surgical resection of a lung metastasis.

METHODS

Between August 1997 and March 2006, 27 patients underwent surgical resections for colorectal lung metastases at Seoul St. Mary's hospital. A retrospective review of patients' characteristics and various tumor factors was performed.

RESULTS

The mean interval between colorectal resection and lung metastasis was 24.0 ± 15.1 months. The overall 3- and 5-year survival rates were 76.5% and 22.2%, respectively. The mean follow-up after pulmonary resection was 39.5 ± 21.6 months (range, 3.3 to 115 months). Except for the existence of hilar-lymph-node metastasis (P < 0.001), no risk factors that we studied were statistically significant. Two patients had hilar-lymph-node metastasis. They survived for only for 3.3- and 11.6-months, respectively.

CONCLUSION

In our study, we found that a pulmonary resection for metastases from colorectal cancer may improve survival in selected patients.

miRNAs in colon and rectal cancer: A consensus for their true clinical value

Numerous miRNAs are deregulated in human cancers and experimental evidence indicates that they can play roles as oncogenes or tumor suppressor genes. Colorectal cancer represents a wide and exciting area of research for molecular biology, due to the growing need of a molecular classification as well as prognostic and predictive molecular factors that may guide oncologists in the clinical management of patients. The aim of this review is to analyze the state of art of the miRNA expression profiles in colorectal cancer to explore some perspectives in this research field.

Overexpression of high-mobility group box 1 correlates with tumor progression and poor prognosis in human colorectal carcinoma

PURPOSE

High-mobility group box 1 (HMGB1) has been implicated in a variety of biologically important processes, including transcription, DNA repair, V(D)J recombination, differentiation, development, and extracellular signaling. The increased expression of HMGB1 has been described in colorectal cancer (CRC). However, there is no report about the correlation of HMGB1 with clinicopathologic features, including the survival of patients with CRC.

METHODS

In present study, we investigated HMGB1 expression and its prognostic significance in CRC by performing immunohistochemical analysis, using a total of 192 paraffin-embedded archival CRC samples. Moreover, disruption of endogenous HMGB1 protein through a siRNA knockdown technique was performed to investigate the possible role of HMGB1 in the process of tumor invasion and metastasis.

RESULTS

Overexpression of HMGB1 was shown in 55.7% cases. Statistical analysis showed that HMGB1 expression was positively correlated with tumor invasion (P = 0.048), lymph node metastasis (P = 0.011), distant metastasis (P = 0.031), and Duke's stage (P = 0.029) of CRC patients. Patients with higher HMGB1 expression had shorter overall survival time, whereas patients with lower level of HMGB1 had better survival. Multivariate analysis suggested that HMGB1 expression might be an independent prognostic indicator for the survival of patients with CRC. Disruption of endogenous HMGB1 protein through a siRNA knockdown technique was shown to suppress substantially the invasion ability of SW620 cells.

CONCLUSIONS

Our results suggest that HMGB1 protein is a valuable marker for progression of CRC patients. High HMGB1 expression is associated with poor overall survival in patients with CRC.

Factors influencing survival after complete resection of pulmonary metastases from colorectal cancer

BACKGROUND

The aim of this retrospective study was to determine the efficacy of complete (R0) resection for pulmonary metastases of colorectal carcinoma, and to clarify prognostic factors for survival that could be used to identify patients likely to benefit most from pulmonary resection.

METHODS

Data on 113 patients who underwent R0 resection of pulmonary metastases from colorectal cancer were reviewed. Overall median follow-up was 49 (range 1-140) months. Clinical and pathological factors were reviewed, and prognostic factors influencing survival were identified.

RESULTS

The overall 5-year survival rate was 67.8 per cent. Multivariable Cox hazard regression analysis revealed that the prethoracotomy serum carcinoembryonic antigen (CEA) level and lymphatic invasion by pulmonary tumour correlated significantly with survival. The 5- and 7-year survival rates of patients with a prethoracotomy CEA level below 5 ng/ml and no lymphatic invasion by pulmonary tumour were 94 and 79 per cent respectively. Pathological features of the primary colorectal cancer, previous hepatectomy for liver metastasis and repeated thoracotomy had no impact on survival.

CONCLUSION

Long-term survival can be expected after R0 resection of pulmonary metastases from colorectal cancer, particularly in patients with a prethoracotomy CEA level below 5 ng/ml and no lymphatic invasion by pulmonary tumour.

Synovial metastasis: an unusual cause of pain after total knee arthroplasty

There is only 1 previous report of synovial metastasis to a joint that has been replaced. A 73-year-old man presented for investigation of continuing pain after a left total knee arthroplasty with normal plain radiographs. Synovial biopsy revealed metastatic adenocarcinoma of colorectal type. A barium enema and flexible sigmoidoscopy showed a suspicious lesion at the rectosigmoid junction. The knee is the most frequently affected joint, and the lung is the most common primary site for synovial metastasis. This phenomenon should be considered in the differential diagnosis of continuing pain and effusion postarthroplasty.

A small mammal model of tumour implantation, dissemination and growth factor expression after partial hepatectomy

BACKGROUND

Surgical resection remains the most effective therapy for metastatic colorectal cancer confined to the liver, although the extrahepatic recurrence rate is high.

AIM OF THE STUDY

To develop a mammal model in order to investigate by which mechanisms liver surgery affects distant tumour recurrence.

METHODS

In this animal study the effect of partial hepatectomy (phX) on the development of tumour noduli in the lungs was evaluated. CC531 rat colon carcinoma cells were inoculated i.v. 24h before, during or 24h after surgery. Rat serum was obtained at different time-points after phX and added to in vitro CC531 cell cultures. Finally, phX was compared with an ileum resection (ilX).

RESULTS

phX leads to increased tumour noduli in the lungs, compared to Sham operation (p=0.002), but only when performed directly before the injection of tumour cells and not when performed 24h before or after the inoculation. Comparable results were obtained for ilX. No growth stimulation of tumour cells after incubation with rat serum, obtained at different time-points after phX, could be detected in vitro.

CONCLUSION

Not only phX, but also surgery, in general promotes distant tumour recurrence exerting the effect during the early phase of tumour cell adhesion and not during tumour outgrowth.

Messenger RNA expression of vascular endothelial growth factor and its receptors in primary colorectal cancer and corresponding liver metastasis

BACKGROUND

Antiangiogenic therapies have been developed recently in combination with traditional chemotherapy for patients with metastatic colorectal cancer. The aim of this study was to clarify the association between messenger RNA (mRNA) levels of vascular endothelial growth factor (VEGF) and its receptors (VEGFR) in primary colorectal cancer and those in corresponding liver metastasis.

METHODS

Thirty-one paired formalin-fixed, paraffin-embedded tumor tissues of colorectal cancer and liver metastasis were dissected by laser capture microdissection. After the mRNA was isolated, a quantitative fluorescent dye real-time reverse transcription-polymerase chain reaction system was used for gene expression measurement.

RESULTS

There was a positive correlation between VEGF mRNA levels in primary colorectal cancer and those in matched liver metastasis (P = .0083, r (s) = 0.48). However, there was no association between mRNA levels of VEGFRs in primary tumor and those in liver metastasis. The mRNA levels of VEGF were associated with those of VEGFR-1 (P = .0026, r (s) = 0.39) but not with those of VEGFR-2. The mRNA levels of VEGF were higher than that of either of the VEGFRs (P < .0001).

CONCLUSIONS

We can predict VEGF mRNA levels, but not those of VEGFRs, in liver metastasis by measuring those in primary colorectal cancer. The mRNA expression of VEGFRs may be more dependent on the surrounding environment than that of VEGF. These results should be useful for the formulation of antiangiogenic therapies for metastatic colorectal cancer. Further studies will be necessary to validate these preliminary data.

Whole genome analysis for liver metastasis gene signatures in colorectal cancer

Liver metastasis is one of the major causes of death in colorectal cancer (CRC) patients. To understand this process, we investigated whether the gene expression profiling of matched colorectal carcinomas and liver metastases could reveal key molecular events involved in tumor progression and metastasis. We performed experiments using a cDNA microarray containing 17,104 genes with the following tissue samples: paired tissues of 25 normal colorectal mucosa, 27 primary colorectal tumors, 13 normal liver and 27 liver metastasis, and 20 primary colorectal tumors without liver metastasis. To remove the effect of normal cell contamination, we selected 4,583 organ-specific genes with a false discovery rate (FDR) of 0.0067% by comparing normal colon and liver tissues using significant analysis of microarray, and these genes were excluded from further analysis. We then identified and validated 46 liver metastasis-specific genes with an accuracy of 83.3% by comparing the expression of paired primary colorectal tumors and liver metastases using prediction analysis of microarray. The 46 selected genes contained several known oncogenes and 2 ESTs. To confirm that the results correlated with the microarray expression patterns, we performed RT-PCR with WNT5A and carbonic anhydrase II. Additionally, we observed that 21 of the 46 genes were differentially expressed (FDR=2.27%) in primary tumors with synchronous liver metastasis compared with primary tumors without liver metastasis. We scanned the human genome using a cDNA microarray and identified 46 genes that may play an important role in the progression of liver metastasis in CRC.

Protein and mRNA characterization in human colorectal carcinoma cell lines with different metastatic potentials

Metastasis, the important characteristic of malignant tumors, is closely associated with a series of changes in the expressions of genes and proteins. In this study, we compared mRNA and protein expressions in a pair of human colorectal carcinoma cell lines named SW620 and SW480 with different metastatic potentials by suppression subtractive hybridization and 2-dimensional gel electrophoresis combined with the matrix-assisted laser desorption/ionization time-of-flight mass spectrometer. After suppression subtractive hybridization and differential screening, 24 differentially expressed gene fragments were obtained, including 9 known genes and 15 novel genes. Nine known genes, such as Cytochrome C, Oxidase II and III, Serum amyloid A, Mitotic Control Protein dis3, Eukaryotic Translation Initiation Factor 4A, function in the process of growth and differentiation, transcription, apoptosis, signal transduction. Six novel genes were found to locate in chromosome 5. Northern blot further confirmed the results. For protein analysis, 16 significantly different protein spots were detected using 2-dimensional gel electrophoresis and peptide mass fingerprinting analysis. The results were confirmed by Western blot. The peptide mass fingerprintings of spots were then compared with the NCBI and SWISS PROT database. The differentially expressed proteins included Galectin-1, Annexin A1, Casein kinase 2, Cytochrome c oxidase subunit VIb, S-100D calcium-binding protein, which may be involved in cell differentiation and proliferation, signal transduction, cell adhesion and migration, and tumor evasion of immune responses. An analysis of these genes and proteins reiterated much of our understanding of the metastatic process and also offered some identified targets without previously characterized functions, especially the novel metastasis associated genes, to be further investigated. Moreover, the results of the phenotypic function-related expression mapping analysis at the mRNA and protein level revealed obvious complementarities, providing important clues for further study of the molecular mechanism of metastasis, metastasis control and possible targets for cancer gene therapy.

Hepatectomy and lung radiofrequency ablation for hepatic and subsequent pulmonary metastases from colorectal carcinoma

BACKGROUND

Lung radiofrequency ablation (RFA) is a relatively safe procedure and may have a useful role in the management of non-surgical candidates with colorectal pulmonary metastases.

METHODS

This study consisted of 30 patients, who had previously undergone hepatectomy for colorectal liver metastases and subsequently developed pulmonary metastases, which were then treated with lung RFA. Lung RFA was performed percutaneously under local anesthesia and conscious sedation. The primary aim of this article was to demonstrate the survival outcome in this particular patient population after lung RFA. The secondary aim was to assess the prognostic indicators for survival after lung RFA.

RESULTS

The median survival after lung RFA was 32 months, with 3-year survival rate of 45%. The following four factors were found to significantly influence survival in univariate analysis: size of the largest pulmonary metastasis (P = 0.032), proximity of metastases to major pulmonary vessels (P = 0.003), pre-lung RFA CEA levels (P = 0.013) and post-lung RFA CEA levels (P = 0.022).

CONCLUSIONS

Lung RFA may have a useful role in the management of non-surgical candidates with colorectal pulmonary metastases.

Radiofrequency ablation versus resection for resectable colorectal liver metastases: time for a randomized trial?

BACKGROUND

Surgical resection is the gold standard in the treatment of resectable colorectal liver metastases (CRLM). In several centers, resection is being replaced by radiofrequency ablation (RFA), even though there is no evidence yet from randomized trials to support this. The aim of this study was to critically review the oncological evidence for and against the use of RFA for resectable CRLM.

METHODS

An exhaustive review of RFA of colorectal metastases was carried out.

RESULTS

Five-year survival data after RFA for resectable CRLM are not available. Percutaneous RFA is associated with worse local control, worse staging, and a small risk of electrode track seeding when compared with resection (level V evidence). For tumors </=3 cm, local control after surgical RFA is equivalent to resection, especially if applied by experienced physicians to nonperivascular tumors (level V evidence). There is indirect evidence for profoundly different biological effects of RFA and resection.

CONCLUSIONS

A subgroup of patients has been identified for whom local control after RFA might be equivalent to resection. Whether this is true, and whether this translates into equivalent survival, remains to be proven. The time has come for a randomized trial.

Pulmonary resection for metastases from colorectal cancer: prognostic factors and survival

BACKGROUND

Pulmonary metastases occur in up to 10% of all patients who undergo curative resection. Surgical resection is an important part in the treatment of pulmonary metastasis from colorectal cancer. We analyzed the treatment outcome and prognostic factors affecting survival in this subset of patients.

MATERIALS AND METHODS

Between October 1994 and December 2004, 59 patients underwent curative resection for pulmonary metastases of colorectal cancer. Uncontrollable synchronous liver and lung metastasis or synchronous colorectal cancer with isolated lung metastasis were excluded from this study. A retrospective review of patient characteristics and factors influencing survival was performed. Survival was analyzed by the Kaplan-Meier method. Comparison between groups were performed by a log-rank analysis and the Cox proportional hazard model.

RESULTS

The 5-year overall survival rate of all patients who received pulmonary resection was 50.3%. The number of pulmonary metastases was significantly related with survival in univariate analysis, but not in multivariate analysis (p = 0.032). Prethoracotomy carcinoembryonic antigen (CEA) level exceeding 5 ng/ml was related with poor survival (p = 0.001). A disease-free interval of greater than 2 years did not correlate with survival after thoracotomy (p = 0.3).

CONCLUSION

The prethoracotomy CEA level and the number of metastases were independent prognostic factors. Resection of pulmonary metastasis from colorectal cancer may result in improved survival or even healing in selected patients. Pulmonary resection of colorectal cancer is regarded as a safe and effective treatment with low morbidity and mortality rates.

Identification of the differential expressive tumor associated genes in rectal cancers by cDNA microarray

AIM: To identify tumor associated genes of rectal cancer and to probe the application possibility of gene expression profiles for the classification of tumors.

METHODS: Rectal cancer tissues and their paired normal mucosa were obtained from patients undergoing surgical resection of rectal cancer. Total RNA was extracted using Trizol reagents. First strand cDNA synthesis was indirectly labeled with aminoallyl-dUTP and coupled with Cy3 or Cy5 dye NHS mono-functional ester. After normalization to total spots, the genes which background subtracted intensity did not exceed 2 SD above the mean blank were excluded. The data were then sorted to obtain genes differentially expressed by ≥ 2 fold up or down in at least 5 of the 21 patients.

RESULTS: In the 21 rectal cancer patients, 23 genes were up-regulated in at least 5 samples and 15 genes were down-regulated in at least 5 patients. Hierachical cluster analysis classified the patients into two groups according to the clinicopathological stage, with one group being all above stage II and one group all below stage II.

CONCLUSION: The up-regulated genes and down-regulated genes may be molecular markers of rectal cancer. The expression profiles can be used for classification of rectal cancer.

Surgical resection of pulmonary metastases from colorectal cancer: Four favourable prognostic factors

BACKGROUND

Surgical resection has been the first choice for treatment of pulmonary metastases from colorectal cancer; however, indications for surgery have yet to be adequately clarified. In considering strategies for the treatment of pulmonary metastases from colorectal carcinoma, determination of disease status as either systemic or pre-systemic is of primary importance. The aim of this study is to define the characteristics of those patients who are most likely to benefit from surgical resection.

METHODS

Fifty-eight patients who underwent pulmonary resection for colorectal metastases were retrospectively reviewed and examined for clinicopathological factors.

RESULTS

Overall, 5-year survival rates were 29%, with a median survival time (MST) of 27 months. Multivariate analysis identified four factors that indicate independent and favourable prognostic impact: three or less tumours, metachronous metastasis, negative hilar and/or mediastinal lymph node metastasis and normal prethoracotomy serum carcinoembryonic antigen level. The 5-year survival rate for 16 patients who satisfied all of these favourable characteristics was 62% (MST = 86 months), which was significantly better than those patients lacking these characteristics. The 5-year survival rate for 13 patients who underwent repeated metastasectomy was 37% (MST = 32 months).

CONCLUSIONS

The four factors selected in our multivariate analysis appear to be favourable factors for the practical identification of those patients who are most likely to benefit from surgical resection. Repeated pulmonary resection for lung-only recurrence may benefit carefully selected patients.

Impact of Prognostic Factors on Clinical Outcome After Resection of Colorectal Pulmonary Metastases

Colorectal cancer is the second leading cause of cancer-related deaths in Western countries. Approximately 35% of patients will have metastatic disease at diagnosis, and an additional 25% of patients with resected stage II/III disease will develop recurrence. In approximately 30% of patients, metastatic disease will be restricted to a single organ, with the liver and lungs accounting for the majority of single organ-site metastases. In recent years, aggressive surgical resection of pulmonary metastases has become increasingly common with the recognition that this offers the best chance of long-term cure despite recent chemotherapeutic advances. Unfortunately, relapse after pulmonary resection remains approximately 70% despite advances in imaging and surgical technique. This review examines prognostic factors that influence survival after resection and repeat resection of pulmonary colorectal metastases and examines the impact of lymph node metastases, chemotherapy, and hepatic metastases on outcome. Pathologic markers that might determine outcome and current literature, which consists mainly of retrospective institutional reports, is reviewed.

Plasma von Willebrand factor level as a prognostic indicator of patients with metastatic colorectal carcinoma

AIM: To evaluate the correlations of plasma von Willebrand factor (vWF) level with the distant metastasis and prognosis of patients with colorectal cancer.

METHODS: A total of 86 patients with histologically confirmed metastatic colorectal cancers receiving treatment at Taipei Veterans General Hospital were enrolled. All patients had measurable metastatic lesions and life expectancies of more than 3 mo. Plasma vWF levels were measured by immuno-turbidimetric assay and compared with results from 40 non-metastatic colorectal cancer patients and 22 healthy controls. Patients with metastatic colorectal cancer were divided into two groups according to serum vWF levels and the differences between these two groups were analyzed using χ² test. Data on age, gender, performance status, location of primary tumor, extent of metastasis, site of metastases, histological differentiation, serum CEA and plasma vWF levels were analyzed to determine association with survival. Survival curves were constructed by Kaplan-Meier product limit method and the data was analyzed using log-rank test on a microcomputer. Multivariate analysis using the Cox’s proportional hazards regression model was then performed to determine the independent prognostic indicators among all of the possible variables.

RESULTS: Colorectal cancer patients were identified as having significantly higher plasma vWF concentrations than healthy controls (P<0.05). Moreover, higher vWF plasma levels were associated with advanced tumor stage (P<0.05) and the presence of multiple metastases (P = 0.014). Patients with lower vWF plasma levels (≤160%) survived significantly longer than those with a higher plasma vWF level (log-rank test, P = 0.0043). By multivariate analysis, plasma vWF levels (P<0.001), the extent of metastasis (P = 0.012), and the performance status (P = 0.014) were identified as independent prognostic factors.

CONCLUSION: Our data indicates that high plasma vWF concentrations correlate with advanced diseases and significantly poor prognosis of patients with metastatic colorectal carcinoma. It may serve as a potential biological marker of disease progression in these patients.

Detection of disseminated tumour cells in the liver of colorectal cancer patients

AIMS

The aim of this study was to assess the incidence and lobar distribution of three surrogate tumour cell markers in biopsies from both liver lobes.

PATIENTS AND METHODS

This study comprised 189 patients for whom DNA and/or RNA was available from both liver lobes and who showed at least one positive marker in one liver lobe. Detection of cytokeratin 20 (CK20) and guanylylcyclase C (GCC) was performed by nested reverse transcription-PCR. For detection of K-ras mutations in codons 12 and 13, a PCR-restriction-fragment-length-polymorphism assay was used.

RESULTS

The incidence of all markers and their combinations was higher in the smaller left lobe than in the larger right lobe (CK20: 62 vs 38%; GCC: 52 vs 48%; K-ras: 61 vs 39%; CK20+GCC: 61 vs 39%; CK20+GCC and/or K-ras: 61 vs 39%). The marker incidence in the two liver lobes was independent from the location of the respective primary colorectal carcinoma.

CONCLUSIONS

The markers CK20, GCC, and K-ras indicating cells shed from the primary CRC were detected more often individually and in combination in biopsies from the smaller left lobe than from the larger right lobe. The site of the primary tumour did not influence the marker incidence in both liver lobes.

Influence of proinflammatory cytokines on the adhesion of human colon carcinoma cells to lung microvascular endothelium

In this experimental study, the influence of surgery-induced proinflammatory cytokines on tumor recurrence in the lung was investigated. A reproducible human in vitro assay was developed to study the adhesion of HT29 colon carcinoma cells to monolayers of microvascular endothelial cells of the lung (HMVECs-L) or human umbilical venous endothelial cells (HUVECs). Preincubation of HMVECs-L with maximally active concentrations of IL-1beta and TNF-alpha, but not with IL-6, resulted in at least 250% adhesion compared to control adhesion (p <or= 0.01). The effect of IL-1beta and TNF-alpha was concentration- and time-dependent. Comparable results were found for HUVECs. Tumor cell adhesion was not increased after preincubation of HT29 with TNF-alpha. Enzyme immunoassays of cytokine-preincubated HUVECs and HMVECs-L showed concentration- and time-dependent upregulation of E-selectin, ICAM-1 and VCAM-1 expression. In addition, LFA-1 and VLA-4 were only expressed on HMVECs-L, creating more binding possibilities for HMVECs-L compared to HUVECs. Inhibition assays with anti-E-selectin monoclonal antibody significantly decreased tumor cell adhesion to HUVECs; however, it did not affect tumor cell adhesion to HMVECs-L. Furthermore, anti-ICAM-1 and anti-VCAM-1 antibodies did not affect adhesion. Our results prove IL-1beta and TNF-alpha promote tumor cell adhesion to HMVECs-L in vitro and may therefore account for enhanced tumor recurrence in the lung seen after major surgical trauma. The adhesion of HT29 to HUVEC is inhibitable by E-selectin antibodies, whereas the adhesion to HMVEC-L is not inhibitable by these antibodies. Probably not one but a complex of adhesion molecules is responsible for enhanced adhesion to HMVECs-L.

The use of a “Liquid” electrode in hepatic electrolysis

BACKGROUND

The use of direct current electrolysis as a local nonthermal ablative technique for colorectal liver metastases promises to be a simple, safe, and effective therapy. Under general anesthesia, electrolysis is presently limited to tumors smaller than 5 cm, due to the protracted nature of its administration. In an attempt to enhance the effect of electrolysis, a direct current was passed through a preinjected bolus of acetic acid.

METHODS

The effect of a combination of electrolysis and an injection of acetic acid was tested in the liver of eight normal pigs. The volumes of necrosis caused were analyzed.

RESULTS

Acetic acid independently produced a volume of necrosis but did not provide a volumetric or rate advantage when used in combination with a direct current. Statistically, the only main effect on the volume of necrosis was a result of electrolysis.

CONCLUSION

The use of 50% acetic acid to augment the efficacy of direct current electrolysis cannot be recommended.

Orthotopic models of cancer for preclinical drug evaluation: advantages and disadvantages

Considering the enormous effort that has taken place over the years to discover new chemotherapeutic drugs for treating the common cancers, the conventional murine and xenograft test systems used to test efficacy for drug development have identified only a limited number of useful agents that are active clinically at well tolerated doses. In recent years, considerable effort has been made to develop more clinically relevant models by the use of orthotopic transplantation of tumour material in rodents. It has been shown that it is now possible to transplant tumour material from a variety of tumour types into the appropriate anatomical site and often these tumours will metastasise in a similar manner and to similar locations as the same tumour type will in human cancer. As yet, although a body of literature has amassed on the technique itself and its implications for metastasis, there are relatively few laboratories using these test systems in drug development programmes. Nevertheless, given the expertise now being developed and some interesting observations being made on the role of the tumour site on response to therapeutic agents, it is likely that the use of orthotopic systems will strengthen our ability to select the most appropriate molecules for recommended use in clinical studies.

Scanning electron microscopy study of the blood supply of human colorectal liver metastases

AIMS

The failure of hepatic artery directed treatment of colorectal liver metastases may reflect a major portal venous contribution to tumour blood supply. This study provides ultrastructural details of the blood supply of colorectal liver metastases and their association with the portal vein and hepatic artery.

METHODS

Resected liver specimens from six patients with colorectal liver metastases were examined by histology and scanning electron microscopy (SEM), following vascular resin casting.

RESULTS

Nine metastatic colorectal adenocarcinomas were identified. The main feature of all tumours on SEM was direct communication between hepatic sinusoids and tumour vessels. A direct portal venous connection with tumour vessels was observed in a single specimen, whilst a direct arteriole connection was not identified.

CONCLUSIONS

It appears that both the hepatic artery and portal vein contribute to the blood supply of colorectal liver metastases through sinusoidal connections with tumour specific blood vessels. SEM provides useful additional information on the morphological features of tumour vasculature.

JTE-522, a selective COX-2 inhibitor, interferes with the growth of lung metastases from colorectal cancer in rats due to inhibition of neovascularization: A vascular cast model study

The lung is a frequent site of metastasis from colorectal cancer, but angiogenesis of lung metastases has not been clarified. Some COX-2 inhibitors prevent tumor growth, although the inhibitory mechanism at the metastatic site is obscure. We investigated the microvascular structure of small lung metastases and the effect of JTE-522, a selective COX-2 inhibitor, on the angiogenesis of pulmonary metastases from colorectal cancer in rats. The tail veins of 25 male F344/DuCrj rats, aged 5 weeks, were injected with a tumor suspension containing 5 x 10(6) RCN-9, a rat colon cancer cell line. Three weeks later, pulmonary vascular resin corrosion casts were taken and the vascularity of metastases was studied using stereo and scanning electron microscopes. We investigated the effect of 0, 10 and 30 mg/kg/day of JTE-522 on the angiogenesis of pulmonary metastases in 3 groups of 5 male rats out of 25. JTE-522 reduced the diameter of tumor vessels as well as the number and size of metastatic tumors. The diameter of tumor vessels and the size of lung metastases significantly and positively correlated with neovascularization in the control group, but not in the JTE-522-treated groups. JTE-522 also affected type of vasculature of metastases, which differed depending on their size. JTE-522 interfered with the growth of hematogenous metastatic tumors by disrupting neovascularization. However, JTE-522 may have some important mechanisms other than inhibition of neovascularization. JTE-522 may be one of the therapeutic agents for the treatment of hematogenous metastasis of colorectal cancer.

Effect of laparotomy and CO(2) pneumoperitoneum on tumor growth of human colon carcinoma and expression pattern of tumor-associated proteins in the SCID mouse

BACKGROUND AND AIMS

The impact of laparoscopy on tumor progression is still unclear. This study investigated the effect of CO(2) pneumoperitoneum on the intra-abdominal growth of human colon carcinoma independently of the effect of the immune system.

METHODS

SCID mice underwent either median laparotomy or laparoscopy. Human colon carcinoma cells were implanted into the upper abdomen. The control group was not operated on following cell injection. Tumor growth and the protein expression pattern of proliferation marker Ki67, cell-cell adhesion molecules E-cadherin, alpha- and beta-catenin, and cell-extracellular matrix adhesion molecules CD44 v5 and v6 in tumor tissue were analyzed on postoperative day 14.

RESULTS

Total tumor volume in the laparoscopy group significantly exceeded that in the laparotomy group. Immunohistochemistry revealed reduced expression of alpha-catenin and elevated expression on beta-catenin and CD44 v5 in the tumor tissue of the laparoscopy group.

CONCLUSION

The expression pattern of proteins associated with tumor progression and the increase in tumor growth suggest an increased risk of laparoscopy at least for the growth of advanced human colon carcinoma.

Laparoscopic port-site metastases: etiology and prevention

OBJECTIVE

The purpose of this article is to summarize current hypotheses for the possible sources of laparoscopic port-site metastasis, to review the results of experimental models that support such hypotheses, and to discuss the potential options for preventing these metastases.

METHODS

We performed a Medline search to identify in vitro and in vivo studies and clinical trials that analyzed port-site metastases associated with laparoscopic surgery. We report the incidence of port-site metastases and causative factors associated with this condition.

RESULTS

The estimated incidence of port-site metastases in all patients undergoing laparoscopic surgery for malignant disease is approximately 1-2%. Multiple factors are associated with this complication. Among the most common proposed etiologies are the wound implantations caused by the surgical technique and instrumentation; the leakage of insufflation gas through the ports, known as the "chimney effect"; and the impact of pneumoperitoneum on local immune reactions. Several preventive measures, have been suggested, including careful patient selection, lavage of the peritoneal cavity as well as of the port wounds with cytotoxic agents, and modifications of surgical technique.

CONCLUSIONS

Only through the results of well-conducted large multi-institutional prospective randomized trials will we learn not only the true incidence of port-site metastases, but also the potential factors that lead to the occurrence of this complication.

Angiogenesis and antiangiogenic therapy of colon cancer liver metastasis

The fact that tumor growth and metastatic spread relies on angiogenesis has been widely proven and accepted. The understanding of cancer biology and metastasis formation has led to the development of new therapeutic approaches that target tumor biology. The survival and establishment of metastatic lesions depend on a shift in the normal balance of proangiogenic and antiangiogenic factors that favor angiogenesis. Colorectal cancer is one of the leading cancer deaths worldwide. Angiogenesis has been associated with colon cancer progression and metastatic spread, thereby significantly affecting patient survival. New experimental approaches that inhibit angiogenic processes have demonstrated promising antineoplastic effects on metastatic colorectal cancer and are partially being investigated in clinical trials. This review focuses on angiogenesis in colorectal cancer metastasis formation as a target for antiangiogenic therapy, describing the experience from experimental studies and current clinical trials.