Hypoxia enhances colon cancer migration and invasion through promotion of epithelial-mesenchymal transition.

BACKGROUND: A hypoxic environment exists in most solid tumors because in rapidly growing tumors, the development of angiogenic vasculature is heterogenous, usually not enough to overcome the necessary oxygen supply. In an ischemic condition, cancer cells develop escape mechanisms to survive and leave the unfavorable environment. That result in the acquisition of increased potential for local invasion and evasion to distant organs. However, the escape mechanisms of cancer cells from hypoxic stress have not been fully characterized. MATERIALS AND METHODS: The human colon cancer cell line LoVo was cultured in hypoxia, and the adhesive and migratory properties were analyzed. The expression of cell surface and cytoplasmic molecules was also investigated. RESULTS: Under hypoxic conditions, cells developed epithelial-mesenchymal transition. The expression levels of α2, α5, and ß1 integrins were significantly upregulated and, as a consequence, the ability to adhere to and migrate on collagen and fibronectin was increased. On the other hand, the expression of 67-kDa laminin receptor and the abilities to adhere to and migrate on laminin were decreased. Additionally, the expression of CXCR4 was significantly increased on cells cultured in hypoxia, and the chemotactic activity to stromal cell-derived factor 1α was remarkably increased. CONCLUSIONS: Hypoxic stress induced active epithelial-mesenchymal transition in colon cancer cells, with the typical morphologic and functional changes. These morphologic and functional changes of ß1 integrins, the 67-kDa laminin receptor, and CXCR4 may be essential for the acquisition of the invasive and metastatic features in colorectal cancer.

One-stage segmental colectomy and primary anastomosis after intraoperative colonic irrigation and total colonoscopy for patients with obstruction due to left-sided colorectal cancer.

BACKGROUND: Intraoperative colonic irrigation and intraoperative on-table colonoscopy may be useful for a more accurate diagnosis of colorectal cancer before colectomy in patients with obstructive left-sided colorectal cancer, but the clinical benefit of this technique has not been investigated in large-scale studies. OBJECTIVE: The aim of this study was to evaluate the usefulness of intraoperative colonic irrigation with a Y-shaped irrigation device and intraoperative colonoscopy in the management of obstructive colorectal cancer in patients undergoing elective surgery. DESIGN AND SETTING: This was a retrospective cohort study of patients undergoing surgical treatment at a single tertiary care institution in Japan. PATIENTS AND INTERVENTION: Among 715 consecutive patients with left-sided colorectal cancer, 101 patients (14.1%) with obstructing tumor received intraoperative colonic irrigation and intraoperative colonoscopy before colectomy and primary anastomosis, and 614 patients with nonobstructive colorectal cancer underwent preoperative colonoscopy with mechanical bowel preparation. MAIN OUTCOME MEASURES: Detection rates of proximal synchronous lesions, occurrence of postoperative complications, and changes in the surgical procedure prompted by the results of the intraoperative colonoscopy were evaluated. RESULTS: Intraoperative colonoscopy detected synchronous adenomatous polyps in 27 patients (26.8%), carcinoma in 4 patients (4%), and obstructive colitis in 2 patients (2%). Findings of the intraoperative colonoscopy prompted changes in surgical procedure in 9 patients (8.9%). The overall morbidity in the intraoperative group was 17%, with anastomotic leakages in 3 patients, wound infection in 5, and postoperative ileus in 3 patients. The risk of these complications was not increased in patients with intraoperative colonoscopy with intraoperative colonic irrigation compared with those receiving preoperative colonoscopy with mechanical bowel preparation. The operation time was 28 minutes longer in the intraoperative than in the preoperative group, but neither the time to start of oral intake nor the length of postoperative hospital stay was significantly different between the 2 groups. LIMITATIONS: The study is limited by its retrospective nature. CONCLUSIONS: : In patients with obstructive colorectal cancer, intraoperative colonic irrigation with intraoperative colonoscopy is a useful strategy for detecting synchronous lesions located proximally to the obstructing tumor, without increasing patient morbidity.

Vagus nerve preservation selectively restores visceral fat volume in patients with early gastric cancer who underwent gastrectomy.

BACKGROUND: Body weight loss is a well-known complication after gastrectomy, and is mainly due to reduced fat volume. The effect of vagotomy on the postoperative fat volume was investigated in patients with early stage gastric cancer who underwent gastrectomy. METHODS: Subcutaneous fat area (SFA) and visceral fat area (VFA) were separately measured in a computed tomographic (CT) image at the level of the umbilicus using Fat Scan software. The changes in these two fat areas were determined by comparing CT images taken before and more than 6 mo after gastrectomy, and the ratio of postoperative to preoperative fat area was calculated in 77 patients. RESULTS: VFA was reduced significantly greater after total gastrectomy (TG) than distal gastrectomy (DG) (P = 0.0003). In 63 patients who underwent DG, the reduction in VFA, but not in SFA, was significantly less in vagus nerve-preserved than in vagus nerve-nonpreserved cases (59.0% ± 24.2% versus 74.9% ± 28.2%, P = 0.027). If compared in each case, VFA showed a significantly greater decrease than did SFA in vagus-nonpreserving, but not in vagus-preserving, gastrectomy (68.2% ± 37.0% versus 52.7% ± 25.2%, P < 0.0001; 76.3% ± 30.0% versus 74.9% ± 28.2%, P = 0.79). CONCLUSIONS: The vagus nerve has a function to locally regulate the amount of intra-abdominal fat tissue, and selective vagotomy in gastrectomy results in a preferential reduction of visceral fat in gastrectomy. Surgical denervation of vagus may be reconsidered as a reasonable treatment for excessive obesity.

CD133(-) cells, derived from a single human colon cancer cell line, are more resistant to 5-fluorouracil (FU) than CD133(+) cells, dependent on the ß1-integrin signaling.

BACKGROUND AND AIM: Recently, the cancer stem cells (CSCs) theory has been proposed, and CD133 has been suggested as a potential marker of CSCs in various cancer types. In the present study, we aimed evaluate CD133 as a potential marker of colorectal CSCs and, for this purpose, isolated CD133(+) and CD133(-) cells from a single colorectal cancer cell line, and compared their features, especially related to the tumor-forming and differentiation abilities, and the sensitivity to chemotherapy. METHODS AND RESULTS: CD133(+) cells had higher in vivo tumor-forming ability than CD133(-) cells, and in culture, they progressively differentiated into CD133(-) cells, but not vice-versa. On the other hand, CD133(-) cells were more resistant to 5-fluorouracil (FU) treatment than CD133(+) cells, and it was found to be dependent on the higher expression of ß1-integrins, and consequently, higher ability to bind collagen. Disruption of the ß1-integrin function abrogated the chemoresistance. CONCLUSION: From the present results, we concluded that colorectal cancer CD133(+) cells, although showing some features of CSCs, are not more resistant to 5-FU than CD133(-) cells. Therefore, definite conclusions can not be drawn yet, but it is strongly suggestive that CD133 should not be used as a single CSC marker of colorectal cancer.

Analysis for the combination expression of CK20, FABP1 and MUC2 is sensitive for the prediction of peritoneal recurrence in gastric cancer.

Prediction of peritoneal recurrence in gastric cancer patients is important for application of adjuvant chemotherapy. After surgery, occasional patients have peritoneal recurrence despite negative cytology of the peritoneal washings. Thus, molecular detection of a subliminal number of cancer cells in peritoneal washings may overcome the sensitivity limitation of conventional cytology. In this study, expressions of five specific marker genes, namely, TFF1, TFF2, CK20, FABP1 and MUC2, were evaluated for their usefulness as markers of micro-dissemination. It was found that reverse transcriptase-polymerase chain reaction for these five genes yielded results highly specific for the depth of invasion and disease stage. Furthermore, the expression of CK20, FABP1 and MUC2 was a reliable prognostic indicator of peritoneal metastasis. Our results suggest that evaluation of the expression of CK20, FABP1 and MUC2 in peritoneal washings is a useful tool for identifying patients at high risk of peritoneal recurrence who may need adjuvant chemotherapy.

Vagus nerve preservation results in visceral fat maintenance after distal gastrectomy.

BACKGROUND/AIMS: Although preservation of the vaguas nerve is recommended in surgery for earlystage gastric cancer, the physiological effect of vagotomy on the postoperative course has not been well documented. We assessed the effect of vagotomy on the change in fat volume after gastrectomy. METHODOLOGY: Subcutaneous fat area (SFA) and visceral fat area (VFA) were separately measured in computed tomographic images taken before and more than 6 months after surgery, using Fat Scan software. The ratios of postoperative/ preoperative values of these two fat areas as well as body weight were calculated in 45 patients who underwent DG with (n=24) or without (n=21) vagotomy. RESULTS: Vagotomy did not affect the change in body weight (91.3±1.7% vs. 92.1±1.7%). In patients with vagotomy, VFA was reduced to 59.0±5.1%, which was significantly greater than the reduction in SFA (74.3±8.7%, p=0.042). In contrast, the reduction ratios of VFA and SFA were equal in vagus nerve-preserved patients (78.4±6.7% vs. 78.2±6.9%, p=0.97). CONCLUSIONS: The vagus nerve may have a function to locally regulate the intra-abdominal fat volume and preservation of the vagus nerve results in the maintenance of visceral fat after DG.

A 1cm distal bowel margin is safe for rectal cancer after preoperative radiotherapy.

BACKGROUND/AIMS: Although guidelines recommend a 2 cm distal margin in sphincter-saving operations for rectal cancer, some studies have shown that it may be decreased to 1cm after preoperative radiotherapy. At the present time, there are no established guidelines that suggest a specific distal safety margin for rectal cancer after preoperative radiotherapy. This study aims to examine whether preoperative radio therapy can reduce the distal safety margin in the treatment of lower rectal cancers. METHODOLOGY: We examined the distal spread by H&E and immunohistochemical staining of CAM5.2 (epithelial marker) in serial sections of surgically resected specimens. To evaluate the extent of distal intramural spread, we defined the "DS length" as the distance between the microscopically defined distal tumor border and the distal spread. We compared the DS length between 20 patients who underwent preoperative radiotherapy followed by surgery (Rad (+) group) and 20 surgery-alone (Rad (-)group). RESULTS: The average DS length was significantly smaller in the Rad (+) group (3.2mm) than in the Rad (-) group (6.3mm) (p=0.028). Furthermore,the greatest DS length was 5.8mm in the Rad (+) group,but 11.5mm in the Rad (-) group. No patient showed a DS length of over 1cm in the Rad (+) group. CONCLUSIONS: These results suggested that the safety margin may be reduced to 1cm by preoperative radiotherapy.Therefore, preoperative radiotherapy may extend the indications for sphincter-saving operation.

Adiponectin supports cell survival in glucose deprivation through enhancement of autophagic response in colorectal cancer cells.

Adiponectin is known to have suppressive effects on tumor growth and is thought to be a key molecule in the positive correlation between obesity and cancer. However, the detailed mechanisms regulating tumor cell activity have not been elucidated. In this study, we found that both full-length (f-Ad) and globular adiponectin (g-Ad) inhibited cell growth in colon cancer cell lines in glucose-containing medium, whereas it supported cell survival in glucose-deprived medium, with an increase in AdipoR1 and AdipoR2 expression. The latter effect of adiponectin in glucose deprivation was significantly inhibited by adding autophagy inhibitors, chloroquine, 3-methyl adenine or a combination of pepstatin A and E-64d, suggesting that the effect of supporting cell growth was dependent, at least in part, on the induction of autophagy. The enhancement of autophagy was confirmed morphologically using green fluorescent protein (GFP)-microtubule-associated protein 1 light chain 3 (LC3) fusion proteins under a fluorescence microscope using stably transfected DLD-1 cells expressing GFP-LC3. Western blot analysis revealed that adiponectin increased the expression of LC3-1, LC3-2, phosphorylated AMPKα and PPARα but decreased that of phosphorylated mTOR, insulin like growth factor (IGF)-1, phosphorylated serine/threonine kinase (Akt) and phosphorylated phosphatidylinositol 3-kinase (PI3K) in glucose-deprived medium. We conclude that adiponectin supports cell survival in glucose deprivation through enhancement of the autophagic machinery by AMPKα and PPARα activation and IGF-1/PI3k/Akt/mTOR pathway inhibition. The bimodal effects of adiponectin are thought to be clinically important in the pathophysiology of tumor development and progression.

Intratumoral injection of interleukin-2 augments the local and abscopal effects of radiotherapy in murine rectal cancer.

Recent studies have suggested that tumor shrinkage in response to radiotherapy (RT) is greatly dependent on the host immune response. A Balb/c mouse model of simultaneous subcutaneous tumor and liver metastasis of Colon26 was prepared and, after irradiation of the subcutaneous tumor (2 Gy × 5 day × 2 cycles), interleukin-2 (IL-2) (2 × 10(4) U) was injected intra-tumorally, and the fate of both the subcutaneous tumor and liver metastatic lesions was evaluated. Intratumoral injection of IL-2 greatly enhanced the anti-tumor effects of RT and completely eradicated the established subcutaneous tumor. Interestingly, although RT was given locally to the subcutaneous tumor, liver metastasis formation was also inhibited in mice receiving only local RT. More impressively, the combination of RT + IL-2 completely inhibited liver metastasis formation. Splenocytes in mice receiving RT + IL-2 contained a higher percentage of CD4(+) T cells, but lower percentages of CD4(+)CD25(+) regulatory T cells and CD11b(+) Gr-1(+) myeloid-derived suppressor cells. Immunohistochemical investigation of human rectal cancer revealed that the density of CD8(+) cells infiltrating into irradiated rectal tumor was positively associated with a lower frequency of distant metastasis as well as histological response grade. Local administration of IL-2 not only enhances shrinkage of the irradiated tumor itself, but can also suppress the development of distant metastasis located outside the RT field, possibly though the induction of a systemic T cell response. Augmentation of T-cell-mediated antitumor immunity during RT might be critical for improvement of the clinical efficacy of neoadjuvant RT for the treatment of advanced rectal cancer.

Spatial distribution of intraperitoneally administrated paclitaxel nanoparticles solubilized with poly (2-methacryloxyethyl phosphorylcholine-co n-butyl methacrylate) in peritoneal metastatic nodules.

Intraperitoneal (i.p.) administration of paclitaxel nanoparticles (PTX-30W) prepared by solubulization with the amphiphilic copolymer of 2-methacryloxyethyl phosphorylcholine and n-butyl methacrylate can efficiently suppress the growth of peritoneal metastasis. In this study, we characterized the drug distribution of i.p. injected PTX-30W in peritoneal tumor and liver in a mouse model using MKN45, human gastric cancer cells. Oregon green-conjugated PTX-30W showed perivascular accumulation in MKN45 tumor in the peritoneum at 24 h after intravenous (i.v.) injection; however, the amount of PTX in tumor was markedly less than that in liver. In contrast, a larger amount of PTX accumulated in the peripheral area of disseminated nodules at 1 h after i.p. injection and the area gradually enlarged. The depth of PTX infiltration reached 1 mm from the tumor surface at 48 h after i.p. injection, and the fluorescence intensity was markedly greater than that in liver. Interestingly, i.p. injected PTX preferentially accumulated in relatively hypovascular areas, and many tumor cells in the vicinity of PTX accumulation showed apoptosis. This unique accumulation pattern and lesser washout in hypovascular areas are thought to be attributable to the superior penetrating activity of PTX-30W, and thus, PTX-30W is considered to be highly suitable for i.p. chemotherapy for peritoneal dissemination.

Loss of sympathetic nerve fibers around intratumoral arterioles reflects malignant potential of gastric cancer.

BACKGROUND: The role and clinical significance of the alteration of sympathetic nerve fibers (SNF) was assessed in gastric cancer. Loss of nerve fibers in malignant tumors has previously been described; however, how dysfunction of the nervous system is involved in cancer progression has not been clarified in clinical studies. MATERIALS AND METHODS: The distribution of SNF was examined in 82 surgically resected gastric cancer specimens with immunohistochemical staining of tyrosine hydroxylase (TH), and the association with clinicopathological findings as well as the clinical outcome of the patients was retrospectively evaluated. RESULTS: Arterioles in the normal gastric wall were totally covered with SNF, while the immunoreactivity to TH was markedly reduced around arterioles in cancer tissue. The degree of loss of SNF was significantly correlated with the depth of invasion (P < .0001) and lymph node metastasis (P < .0001) as well as microvessel density (MVD) (P = .0043). Moreover, patients who had tumors with marked loss of SNF showed a markedly worse clinical outcome, with an independent association by multivariate analysis. CONCLUSIONS: Loss of periarteriolar SNF is associated with aggressive phenotype of gastric cancer possibly through enhanced angiogenesis and thus could be a useful marker to predict the clinical outcome.

FOLFOX as adjuvant chemotherapy after curative resection of distant metastases in patients with colorectal cancer.

OBJECTIVES: The prophylactic effect of FOLFOX regimen, a standard regimen for unresectable colorectal cancer (CRC), was investigated in the adjuvant setting of CRC cases with distant metastases. METHODS: The study population included 116 CRC patients with synchronous metastases and 91 patients with metachronous metastases who had undergone curative operation in our hospital between 2000 and 2009. Clinicopathological parameters of CRC, postoperative chemotherapeutic regimen, recurrence rate, and relapse-free survival (RFS) were analyzed retrospectively. RESULTS: After resection of CRC and synchronous metastases, 53 (84%) out of 63 patients without chemotherapy, and 38 (83%) out of 46 that received 5-fluorouracil (5-FU) alone or with leucovorin (LV) developed recurrent tumors. By contrast, only 1 (17%) among 6 patients who underwent FOLFOX treatment showed recurrence. The FOLFOX group exhibited significantly improved RFS as compared to the 5-FU (+ LV) or surgery-alone group (p = 0.03, p = 0.007, respectively). On the other hand, in patients with metachronous metastases, tumor-relapse rate and RFS were not significantly influenced by post-metastasectomy therapies. CONCLUSIONS: In this retrospective analysis, the adjuvant administration of FOLFOX appeared to reduce the risk of relapse in a small group of CRC patients with synchronous metastases. Prospective randomized trials will be required to confirm the benefits of this management strategy.

Circulating lymphocyte is an important determinant of the effectiveness of preoperative radiotherapy in advanced rectal cancer.

BACKGROUND: Although preoperative radiotherapy (RT) is widely used as the initial treatment for locally advanced rectal cancer (RC) in the neoadjuvant setting, factors determining clinical response have not been adequately defined. In order to find other factors possibly related with radiosensitivity, we evaluated the relationships between circulating blood cell counts and RT effects. METHODS: In 179 cases with advanced RC, we retrospectively examined hemoglobin (Hb) levels and counts of white blood cells (WBC), platelets and WBC subsets before and after RT and investigated their associations with the complete response (CR) rate together with other clinicopathological factors. RESULTS: The ratio of lymphocytes in WBC taken before RT was significantly greater in 15 CR cases as compared with those in non-CR cases. Patients with high lymphocyte percentages (25.7%) showed better outcome than the counterparts. Conversely, the ratio of neutrophiles was reduced in CR cases. The lymphocyte ratio showed an independent association with CR with multivariate analysis, and tended to be maintained at relatively high levels in CR cases. CONCLUSIONS: In RC patients, peripheral blood lymphocytes have a significant impact on the CR rate in response to RT. Lymphocyte-mediated immune reactions are supposed to have positive roles on clinical response in radiotherapy for RC.

Hyperfibrinogenemia after preoperative chemoradiotherapy predicts poor response and poor prognosis in rectal cancer.

PURPOSE: Although hyperfibrinogenemia has been reported in patients with colorectal cancer, neither its clinical implications nor the effect of chemoradiotherapy (CRT) on the fibrinogen levels have been fully investigated. We investigated the clinical significance of pre- and post-CRT fibrinogen levels in patients with rectal cancer. METHODS: The medical records of 82 patients with rectal cancer, who had received CRT followed by surgical resection, were retrospectively reviewed. The correlation between the clinicopathological variables and the pre- and post-CRT plasma fibrinogen levels, and that between the changes of fibrinogen, C-reactive protein (CRP), or carcinoembryonic antigen (CEA) levels after CRT and the pathological tumor regression grading was analyzed. Furthermore, the impact of post-CRT fibrinogen levels on the prognosis of these patients was assessed. RESULTS: Plasma fibrinogen markedly decreased after CRT. The post-CRT fibrinogen level significantly correlated with lymphatic invasion, venous invasion, tumor size, depth of invasion, and the pathological tumor regression grading. The CRT-induced pathological tumor regression grading well correlated with the decrease of fibrinogen level, but not with that of CRP or CEA. Furthermore, patients with high post-CRT fibrinogen had significantly shorter disease-free survival. CONCLUSIONS: Reduction of plasma fibrinogen induced by CRT should be a promising biomarker for evaluating the efficacy of CRT in rectal cancer patients.

Catechin inhibits adhesion and migration of peripheral blood B cells by blocking CD11b.

CONTEXT: Previously, we demonstrated that CD11b is expressed on peripheral blood memory B cells, and it plays an important role in the migration of B cells. And epigallocatechin gallate (EGCG), a bioactive component of green tea, by binding to CD11b, expressed on CD8(+) cytotoxic T cells, inhibited their migratory ability, one possible mechanism of the antiallergic activity of EGCG. OBJECTIVE: Here, we investigated whether EGCG also affected CD11b expressed on B cells, similar to cytotoxic T cells. MATERIALS AND METHODS: Isolated peripheral blood CD19(+) B cells were treated with EGCG and the change in the expression of CD11b was analyzed using flow cytometry. The effects of EGCG on the ability of B cells to adhere to and to transmigrate through the endothelial cell layer were evaluated using the transwell assay. RESULTS: EGCG significantly suppressed the apparent expression of CD11b on B cells, in the flow-cytometric analysis, and this apparent suppression was speculated to be dependent on the competitive binding of EGCG to CD11b. EGCG also significantly suppressed CD11b-mediated migration and adhesion of B cells to endothelial cells. DISCUSSION AND CONCLUSION: EGCG has a strong suppressive activity on the adhesive and migratory abilities of peripheral blood B cells. This suppressive activity was mediated by the binding of EGCG to CD11b on B cells, and the consequent suppression of B-cell extravasation to the extravascular space. Because B cell plays an important role in the humoral immunity, EGCG could be a promising drug for the prevention and/or treatment of allergic and/or autoimmune diseases.

Free colonic perforation in a patient with Crohn's disease and loop ileostomy: report of a case.

Free bowel perforation in Crohn's disease is a relatively rare complication. In this report, we present a case of free colonic perforation in a Crohn's disease patient with loop ileostomy previously constructed for intractable perianal abscess. Normally, fecal diversion by ileostomy results in an improvement in Crohn's colitis. However, in some cases, fecal diversion is reported to adversely affect the inflammation of the diverted bowel, and it is this unusual complication of Crohn's disease that we discuss here.

Gene expression of mesenchyme forkhead 1 (FOXC2) significantly correlates with the degree of lymph node metastasis in colorectal cancer.

In stage III colorectal cancer, patients with N1 stage tumors show poorer outcome than patients with N2 stage tumors. Our objective was to identify genes that are predictive for the presence of lymph node metastasis, and to characterize the aggressiveness of lymph node metastases. Gene expression profiles of colorectal cancer were determined by microarray in training (n = 116) and test (n = 25) sets of patients. We identified 40 discriminating probes in patients with and without lymph node metastases. Using these probes, we could predict the presence of lymph node metastasis with an accuracy of 87.1% (training set) and 76.0% (test set). Among discriminating probes, FOXC2 expression was significantly correlated with the degree of lymph node metastasis. FOXC2 was expressed significantly and disparately in patients with N1 and N2 stage tumors as analyzed by real-time reverse transcriptase-polymerase chain reaction. FOXC2 appears to be involved in determining the aggressiveness of lymph node metastasis in colorectal cancer.

[FOLFOX as adjuvant chemotherapy after curative resection of distant metastatic lesions in patients with colorectal cancer].

We investigated the effectiveness of prophylactic FOLFOX after curative resection of synchronous metastases in patients with colorectal cancer (CRC). Clinicopathological information including postoperative chemotherapy, such as a therapeutic regimen, relapse-free survival (RFS), site of recurrence, etc., was retrospectively analyzed in 116 CRC patients with synchronous distant metastases, and 63 patients with metachronous metastases who had received surgery in our hospital between 2000 and 2009. Fifty-three patients (84%) out of 63 without adjuvant chemotherapy, and 38 (83%) out of 46 patients that received oral or intravenous 5-fluorouracil (5-FU) (alone or with leucovorin (LV)or isovorin) developed recurrent tumor(s) afterwards. The median RFSs were 119 and 281 days, respectively. By contrast, a single patient among 6 who underwent FOLFOX (up to 12 therapeutic courses) showed recurrence 476 days after surgery. The RFS of the FOLFOX was significantly higher than that of the 5-FU (+LV) or surgery alone (p=0. 03, p=0. 007, respectively). In conclusion, the FOLFOX regimen is more beneficial for CRC patients with synchronous metastasis as adjuvant chemotherapy than 5-FU (+LV) or other followup strategies.

The inhibition of autophagy potentiates anti-angiogenic effects of sulforaphane by inducing apoptosis.

BACKGROUND: Sulforaphane (SUL), a kind of isothiocyanate, has recently been focused due to its strong pro-apoptotic effect on cancer cells as well as tumor vascular endothelial cells (ECs). And recently, we demonstrated the induction of autophagy by colon cancer cells as a protective mechanism against SUL. In the present study, we aimed to investigate the possible role of autophagy induction by ECs as a defense mechanism against SUL. METHODS: Human umbilical vein endothelial cells (HUVECs) were used as the in vitro model of angiogenic ECs. The induction of autophagy was evaluated by the detection of acidic vesicular organelles (AVOs) by flow-cytometry, after the staining with acridine orange, as well as the detection of light chain 3(LC3) by Western blot. Finally, the functional implication of autophagy inhibition and SUL treatment in ECs was investigated by their ability to form vascular-like structures on Matrigel. RESULTS: Treatment of HUVECs with relatively low concentrations of SUL for 16 h resulted in the evident formation of AVOs and the recruitment of LC3 to autophagosomes, the pathognomonic features of autophagy. Co-treatment of cells with the specific autophagy inhibitor (3-methyladenine) potentiated the proapoptotic effect of SUL. And inhibition of autophagy potentiated the inhibitory effect of SUL on the ability of ECs to form capillary-like structures. CONCLUSION: Similar to cancer cells, ECs induced autophagy in response to the pro-apoptotic agent, SUL, and the inhibition of autophagy potentiated the pro-apoptotic effect. These findings open premises for the use of autophagy inhibitors in combination with anti-angiogenic agents.

Inhibition of autophagy potentiates sulforaphane-induced apoptosis in human colon cancer cells.

BACKGROUND: Sulforaphane (SUL), an isothiocyanate naturally present in widely consumed vegetables, particularly broccoli, has recently attracted attention due to its inhibitory effects on tumor cell growth by inducing apoptosis. We investigated the ability of SUL to induce autophagy in human colon cancer cells and whether inhibition of autophagy could potentiate the proapoptotic effect of SUL. METHODS: The proliferation of cells treated with SUL was assessed by MTS assay and colony-forming assay. Apoptosis and caspases activity were investigated by flow cytometry. The formation of acidic vesicular organelles (AVOs) was detected in acridine-orange-stained cells by flow cytometry. Western blotting was used for the detection of light chain 3 (LC3). Localizations of LC3 and cytochrome c were analyzed by immunocytochemistry. RESULTS: The proapoptotic effect was observed by treatment of cells with relatively high concentrations of SUL for long periods of time. After 16 h of treatment, evident formation of AVOs and recruitment of LC3 to autophagosomes, features of autophagy, were observed. Treatment of cells with a specific autophagy inhibitor (3-methyladenine) potentiated the proapoptotic effect of SUL, which was dependent on the activation of caspases and the release of cytochrome c to the cytosol. CONCLUSION: The present results demonstrate induction of autophagy in colon cancer cells as a protective reaction against the proapoptotic effect of SUL, and consequently, the potentiation of the proapoptotic effect by autophagy inhibition. These findings provide a premise for use of autophagy inhibitors in combination with chemotherapeutic agents for treatment of colorectal cancer.