Synergistic Chemopreventive Effects of a Novel Combined Plant Extract Comprising Gallic Acid and Hesperidin on Colorectal Cancer.

BACKGROUND/AIM: Colorectal cancer (CRC) is the third most common cancer with a high mortality rate worldwide. Although gallic acid and hesperidin exert anticancer activity, synergistic effects of gallic acid and hesperidin against CRC remain elusive. This study aims to investigate the therapeutic mechanism of a novel combination of gallic acid and hesperidin against CRC cell growth, including cell viability, cell-cycle-associated proteins, spheroid formation, and stemness. METHODS: Gallic acid and hesperidin derived from Hakka pomelo tea (HPT) were detected by colorimetric methods and high-performance liquid chromatography using ethyl acetate as an extraction medium. CRC cell lines (HT-29 and HCT-116) treated with the combined extract were investigated in our study for cell viability (trypan blue or soft agar colony formation assay), cell cycle (propidium iodide staining), cell-cycle-associated proteins (immunoblotting), and stem cell markers (immunohistochemistry staining). RESULTS: Compared with other extraction methods, HPT extraction using an ethyl acetate medium exerts the most potent effect on inhibiting HT-29 cell growth in a dose-dependent manner. Furthermore, the treatment with combined extract had a higher inhibitory effect on CRC cell viability than gallic acid or hesperidin alone. The underlying mechanism was involved in G1-phase arrest and Cip1/p21 upregulation that could attenuate HCT-116 cell proliferation (Ki-67), stemness (CD-133), and spheroid growth in a 3D formation assay mimicking in vivo tumorigenesis. CONCLUSION: Gallic acid and hesperidin exert synergistic effects on cell growth, spheroids, and stemness of CRC and may serve as a potential chemopreventive agent. Further testing for the safety and effectiveness of the combined extract in large-scale randomized trials is required.

Application of trastuzumab emtansine in HER-2-positive and KRAS/BRAF-mutated colon cancer cells.

BACKGROUND: Trastuzumab emtansine (T-DM1) is an antibody-drug conjugate (ADC) for the treatment of human epidermal growth factor receptor 2 (HER-2)-positive breast cancer. T-DM1 is based on the trastuzumab antibody and delivers a toxic agent into breast cancer cells through endocytic mechanism. This study evaluated whether T-DM1 can be used in HER-2-positive colon cancer cells which harbour KRAS/ BRAF mutation with limited treatment. MATERIALS AND METHODS: LS174T and HT-29 which are KRAS and BRAF mutant HER-2-positive colon cancer cells were used in this study. Cells were first treated with T-DM1; cetuximab and trastuzumab were applied for comparison, the effect of drug sensitivity was determined. Cells were then transfected with plasmid to overexpress HER-2 or the endocytic protein, caveolin-1 or furthermore pretreated with metformin to examine the effect of T-DM1 efficacy. Finally, a xenograft mouse model was used to evaluate the drug efficacy in vivo. RESULTS: The results showed that T-DM1 had better inhibitory effect than cetuximab and trastuzumab on LS174T and HT-29 cells. HER-2 or caveolin-1 overexpression with plasmid in the cells to increase T-DM1 recognition or internalization can increase the sensitivity to T-DM1. When cells were pretreated with metformin, caveolin-1 expression was induced and promoted T-DM1 uptake and enhanced cell toxicity. In xenograft mouse model, combined treatment of T-DM1 and metformin had apparent inhibitory effect on subcutaneous tumour growth. CONCLUSION: The results of this study suggested that T-DM1 has potential in the treatment of HER-2-positive colon cancer cells, and application of metformin has therapeutic benefits during T-DM1 treatment.

Synergistic Effect of Combined Treatment with Longan Flower Extract and 5-Fluorouracil on Colorectal Cancer Cells.

To investigate the influence of longan flower extract (LFE) on the sensitization of colorectal cancer (CRC) cells to 5-fluorouracil (5-FU) treatment, HT-29, Colo 320DM and SW480 cells were treated with LFE and 5-FU alone and in combination, and the cell viability was then assessed by trypan blue exclusion, the cell cycle by propidium iodide staining, the mitochondria membrane potential by rhodamine 123 staining, and the expression levels of associated genes by immunoblotting and quantitative real-time polymerase chain reaction. LFE and 5-FU synergistically inhibited cell proliferation of HT-29 and Colo 320DM cells. Combined treatment also elevated the level of loss of mitochondria membrane potential of these two CRC cells and arrested HT-29 cells in the S phase of the cell cycle, in association with down-regulation of cyclin A mRNA expression. LFE synergistically potentiated chemosensitivity to 5-FU in at least two CRC cell lines. The results indicated that LFE has potential as a novel agent for the sensitization of CRC cells to 5-FU.

Litchi seed extract inhibits epidermal growth factor receptor signaling and growth of Two Non-small cell lung carcinoma cells.

BACKGROUND: Litchi seeds possess rich amounts of phenolics and have been shown to inhibit proliferation of several types of cancer cells. However, the suppression of EGFR signaling in non-small cell lung cancer (NSCLC) by litchi seed extract (LCSE) has not been fully understood. METHODS: In this study, the effects of LCSE on EGFR signaling, cell proliferation, the cell cycle and apoptosis in A549 adenocarcinoma cells and NCI- H661 large-cell carcinoma cells were examined. RESULTS: The results demonstrated that LCSE potently reduced the number of cancer cells and induced growth inhibition, cell-cycle arrest in the G1 or G2/M phase, and apoptotic death in the cellular experiment. Only low cytotoxicity effect was noted in normal lung MRC-5 cells. LCSE also suppressed cyclins and Bcl-2 and elevated Kip1/p27, Bax and caspase 8, 9 and 3 activities, which are closely associated with the downregulation of EGFR and its downstream Akt and Erk-1/-2 signaling. CONCLUSION: The results implied that LCSE suppressed EGFR signaling and inhibited NSCLC cell growth. This study provided in vitro evidence that LCSE could serve as a potential agent for the adjuvant treatment of NSCLC.

Rab11 collaborates E-cadherin to promote collective cell migration and indicates a poor prognosis in colorectal carcinoma.

BACKGROUND: Collective cell migration, whereby the cell-cell contacts such as E-cadherin are maintained during migration, has only recently emerged, and its detailed mechanisms are still unclear. In this study, the role of Rab11, which functions in recycling endosomes, and its relationship to E-cadherin in colorectal carcinoma were identified, and the role of Rab11 in the collective cell migration of colon cancer cells was clarified. MATERIALS AND METHODS: A total of 107 patients with surgically resected colorectal carcinoma were enrolled in this immunohistochemical study. Relationships between the overexpression of Rab11 and E-cadherin and survival were evaluated. The cell biology of Rab11 overexpression or knock-down in HT-29 colon cells was studied. RESULTS: The expression of Rab11 and E-cadherin was not correlated with the stage of cancer or lymph node metastasis. However, the overall survival was poor in the group of 67 patients with duo-positive Rab11 and E-cadherin expression compared to the group (40 patients) without dual-positive expression (P = 0·038). Rab11 was demonstrated to have a physical interaction with E-cadherin, and overexpression of Rab11 was found to promote collective cell migration through the increased distribution of E-cadherin, which enhanced cell-cell connections. In addition, Rac1 activation and matrix metalloproteinase-2 expressions were upregulated upon Rab11 expression. CONCLUSIONS: This study demonstrated that Rab11 and E-cadherin expressions are indicators of poor survival time in colorectal carcinoma, but that Rab11 overexpression may contribute to increased collective cell invasion in colorectal carcinoma.

Rab11 regulates E-cadherin expression and induces cell transformation in colorectal carcinoma.

BACKGROUND: In the process of epithelial mesenchymal transition EMT, the disassembly of junctional adhesion complexes such as E-cadherin is a remarkable sign during changes in cell morphology and polarity. However, E-cadherin expression is dynamic, and is regulated by the cellular endocytic system; it is also involved in cell signaling mechanisms. In this study, we investigated the role of E-cadherin in colorectal tumors and the relationship with recycling endosome protein Rab11 in colon cell transformation. METHODS: For tissue screening, the expressions of E-cadherin and Rab11 in colorectal tumors were identified by immunohistochemistry in 113 patients with colorectal carcinoma. For the in vitro cell experiment, GFP-tagged Rab11 plasmid was transfected into HT29 colon cells, E-cadherin expression and cell transformation were monitored by Western blot and confocal microscopy. RESULTS: In immunohistochemistry, the mean score of E-cadherin in tumor and normal tissues was 1.41 ± 0.06 and 1.08 ± 0.06 (p < 0.05). The mean score of Rab11 in tumor and normal tissues was 0.51 ± 0.05 and 0.18 ± 0.02 (p < 0.05). Synchronous overexpression of E-cadherin and Rab11 was noted in 74 patients (66.5%) with colorectal carcinoma. When GFP-tagged Rab11 plasmid was overexpressed in cultured colon cell line HT-29, the E-cadherin expression was up-regulated, and cell membrane protrusion was induced, which resulted in cell transformation and cell migration. CONCLUSIONS: This study demonstrated the importance of the overexpression of Rab11 and E-cadherin in colorectal cancer. The results indicated that Rab11 together with E-cadherin might be potential markers for colorectal cancer progression and treatment.

Runx1-deficient afferents impair visceral nociception, exacerbating dextran sodium sulfate-induced colitis.

Colitis is a group of inflammatory and auto-immune disorders that affect the tissue lining of the gastrointestinal (GI) system. Studies of chemically-induced animal models of colitis have indicated that nociceptive afferents or neuropeptides have differing effects on GI inflammation. However, the molecular mechanisms involved in visceral pain and the role of visceral sensory afferents involved in the modulation of colitis remains unclear. A previous study demonstrated that Runx1, a Runt domain transcription factor, is restricted to nociceptors. In these neurons, Runx1 regulates the expression of numerous ion channels and receptors, controlling the lamina-specific innervation patterns of nociceptive afferents in the spinal cord. Moreover, mice that lack Runx1 exhibit specific defects in thermal and neuropathic pain. To examine the function of Runx1 in visceral nociception, we employed double-transgenic mice (WntCre: Runx1(F/F)), in which the expression of Runx1 was specifically disrupted in the sensory neurons. To determine the role of Runx1 in visceral pain sensation, the WntCre: Runx1(F/F) mice and their control littermates (Runx1(F/F)) were treated using dextran sodium sulfate (DSS) to induce colitis. The results indicated that disrupted Runx1 in the sensory afferents resulted in: (1) impairment of the visceral pain sensation in murine DSS-induced colitis; (2) exacerbating the phenotypes in murine DSS-induced colitis; (3) a differential effect on the production of pro- and anti-inflammatory cytokines in the colon tissues isolated from mice treated using DSS and 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis; and (4) alteration of the distribution of lymphocytes and mast cells in mucosa. These results show that the function of Runx1 in sensory afferents is vital for modulating visceral pain and the neuro-immune axis.

Tocilizumab Exerts Anti-Tumor Effects on Colorectal Carcinoma Cell Xenografts Corresponding to Expression Levels of Interleukin-6 Receptor.

The use of tocilizumab against the interleukin-6 receptor (IL-6R) has been demonstrated as inhibiting the progression of diverse cancers in vitro and in vivo. Nonetheless, evidence regarding the anti-tumor effects of tocilizumab on human colorectal carcinoma (CRC) corresponding to IL-6R expression levels remains scarce. To investigate the influence of IL-6R expression, SW480 and HT-29 cells inoculated subcutaneously into NU/NU mice were used as human CRC xenograft models with anti-IL-6R antibody (tocilizumab) therapy. The IL-6R expression levels, histology of CRC growth/invasiveness, and tumor growth-related signaling pathway were estimated by H&E and immunohistochemical staining. SW480 tumor cells with higher IL-6R expression levels showed better responsiveness in tocilizumab therapy than in the treated HT-29 group. Likewise, therapeutic effects of tocilizumab on the proliferative ability with mitotic index and Ki-67 expressions, invasiveness with MMP-9 proteinase expressions, and ERK 1/2 and STAT3 signaling transduction in the SW480 treatment group were superior to the HT-29 treatment group. In light of our results, IL-6R is the key indicator for the efficacy of tocilizumab treatment in CRC xenografts. From the perspective of precision medicine, tumor response to anti-IL-6R antibody therapy could be predicted on the basis of IL-6R expression levels. In this manner, tocilizumab may serve as a targeted and promising anti-CRC therapy.

Disrupting the CXCL12/CXCR4 axis disturbs the characteristics of glioblastoma stem-like cells of rat RG2 glioblastoma.

BACKGROUND: Glioblastoma stem-like cells (GSC) have been shown to promote tumor growth, tumor-associated neovascularization, therapeutic resistance, and metastasis. CXCR4 receptors have been found involved in the proliferation, metastasis, angiogenesis, and drug-resistant characteristics of glioblastoma. However, the role of CXCR4 in modulating the stem-like cell properties of rat glioblastoma remains ambiguous. METHODS: To explore the role of the CXCL12/CXCR4 axis in maintaining rat GSC properties, we disrupted the CXCR4 signaling by using small hairpin interfering RNA (shRNA). To investigate the role of the CXCL12/CXCR4 axis in maintaining rat GSC properties, we used a spheroid formation assay to assess the stem cell self-renewal properties. A western blot analysis and PCR arrays were used to examine the genes involved in proliferation, self-renewal, and cancer drug resistance. Finally, DNA content and flow cytometry, an immunohistochemical analysis, and methylcellulose colony formation, in vitro invasive and intracranial injection xenograft assays were employed to examine the disruptive effect of CXCR4 on the characteristics of GSCs of the RG2 cell line. RESULTS: Disrupting CXCR4 inhibited the proliferation of RG2 cells both in vitro and in vivo. The spheroid formation assay indicated that CXCR4 was vital for the self-renewal of RG2 GSCs. Disrupting the CXCL12/CXCR4 pathway also reduced the expression of GSC cell markers, including Nestin, ABCG2, and musashi (Msi), and the expression of genes involved in regulating stem cell properties, including Oct4, Nanog, maternal embryonic leucine zipper kinase (MELK), MGMT, VEGF, MMP2, and MMP9. CONCLUSION: The chemokine receptor CXCR4 is crucial for maintaining the self-renewal, proliferation, therapeutic resistance, and angiogenesis of GSCs of rat RG2 glioblastoma.

3-D illustration of network orientations of interstitial cells of Cajal subgroups in human colon as revealed by deep-tissue imaging with optical clearing.

Morphological changes of interstitial cells of Cajal (ICC) have been proposed to characterize motility disorders. However, a global view of the network orientations of ICC subgroups has not been established to illustrate their three-dimensional (3-D) architectures in the human colon. In this research, we integrate c-kit immunostaining, 3-D microscopy with optical clearing, and image rendering to present the location-dependent network orientations with high definition. Full-depth colonic tissues were obtained from colectomies performed for nonobstructing carcinoma. Specimens of colon wall were prepared away from the tumor site. C-kit and nuclear fluorescent staining were used to identify the ICC processes and cell body. Optical clearing was used to generate transparent colon specimens, which led to panoramic visualization of the fluorescence-labeled ICC networks at the myenteric plexus (ICC-MY), longitudinal (ICC-LM) and circular (ICC-CM) muscles, and submucosal boundary (ICC-SM) up to 300 µm in depth via confocal microscopy with subcellular level resolution. We observed four distinct network patterns: 1) periganglionic ICC-MY that connect with ICC-LM and ICC-CM, 2) plexuses of ICC-LM within the longitudinal muscle and extending toward the serosa, 3) repetitive and organized ICC-CM layers running parallel to the circular muscle axis and extending toward the submucosa, and 4) a condensed ICC-SM layer lining the submucosal border. Among the four patterns, the orderly aligned ICC-CM layers provide an appropriate target for quantitation. Our results demonstrate the location-dependent network orientations of ICC subgroups and suggest a practical approach for in-depth imaging and quantitative analysis of ICC in the human colon specimen.

Induction of apoptosis and cell cycle arrest in human colorectal carcinoma by Litchi seed extract.

The Litchi (Litchi chinensis) fruit products possess rich amounts of flavanoids and proanthocyanidins. Its pericarp has been shown to inhibit breast and liver cancer cell growth. However, the anticolorectal cancer effect of Litchi seed extract has not yet been reported. In this study, the effects of polyphenol-rich Litchi seed ethanol extract (LCSP) on the proliferation, cell cycle, and apoptosis of two colorectal cancer cell lines Colo320DM and SW480 were examined. The results demonstrated that LCSP significantly induced apoptotic cell death in a dose-dependent manner and arrested cell cycle in G2/M in colorectal carcinoma cells. LCSP also suppressed cyclins and elevated the Bax : Bcl-2 ratio and caspase 3 activity. This study provides in vitro evidence that LCSP serves as a potential chemopreventive agent for colorectal cancer.

Carbonic Anhydrase VIII (CAVIII) Gene Mediated Colorectal Cancer Growth and Angiogenesis through Mediated miRNA 16-5p.

Carbonic anhydrase VIII (CAVIII) is a member of the CA family, while CA8 is the oncogene. Here we observed increased expression of CAVIII with high expression in colorectal cancer tissues. CAVIII is also expressed in more aggressive types of human colorectal cancer cells. Upregulated CAVIII expression in SW480 cell lines increased vascular endothelial growth factor (VEGF) and reduced miRNA16-5p. Conversely, knockdown of the CAVIII results in VEGF decline by up-regulated miRNA16-5p. Moreover, the collection of different grades of CAVIII expression CRC cells supernatant co-culture with endothelial progenitor cells (EPCs) promotes the ability of tube formation in soft agar and migration in the Transwell experiment, indicating that CAVIII might facilitate cancer-cell-released VEGF via the inhibition of miRNA16-5p signaling. Furthermore, in the xenograft tumor angiogenesis model, knockdown of CAVIII significantly reduced tumor growth and tumor-associated angiogenesis. Taken together, our results prove that the CAVIII/miR-16-5p signaling pathway might function as a metastasis suppressor in CRC. Targeting CAVIII/miR-16-5p may provide a strategy for blocking its metastasis.

Anti-interleukin-6 receptor antibody inhibits the progression in human colon carcinoma cells.

BACKGROUND: Interleukin-6 (IL-6) promotes proliferation and invasion in colorectal carcinoma, and serum IL-6 levels are correlated with survival in patients with colorectal carcinoma. In this study, we attempted to clarify the signal pathway downstream of IL-6 and the role of the IL-6 receptor complex in terms of the biological effects of clonogenic growth and invasiveness in colorectal carcinoma cells. MATERIALS AND METHODS: IL-6-stimulated SW480 cells were treated with IL-6 receptor neutralization antibody, mitogen-activated protein kinase (MAPK) inhibitor and phosphatidylinositol 3-kinase inhibitor, and clonogenic growth and invasiveness were assessed. IL-6 and IL-6 receptor-expressing LoVo cells were also tested the IL-6 receptor antibody effect. The downstream molecules of the IL-6-mediated pathway were also evaluated. RESULTS: IL-6 effectively enhanced the clonogenicity and invasiveness of SW480; however, these abilities were reversed by treatment with anti-IL-6 receptor antibody, and MAPK and PI3K inhibitors exhibited partial ability to reduce these effects. Similar effects were also found in anti-IL-6 receptor antibody-treated LoVo cells in addition of modulating STAT3 pathway. Anti-IL-6 receptor antibody also inhibited matrix metalloproteinase-2 (MMP-2) and 9 (MMP-9) expressions in IL-6-stimulated SW480. CONCLUSIONS: IL-6 and the IL-6R complex could induce clonogenic growth and invasiveness by mediating signals in the Ras/MAPK and PI3K/AKt pathways, and the malignant phenotypes might be associated with the production of MMP-2 and MMP-9 after IL-6 stimulation in SW480 cancer cells.

Antibody to Interleukin-6 Receptor Inhibits In Vivo Growth of Human Colorectal Carcinoma Cell Xenografts.

BACKGROUND: Interleukin-6 receptor antibody (IL6R) inhibits colony formation and invasion by colorectal carcinoma (CRC) in vitro. We examined the effect of IL6R antibody on tumor growth of CRC xenografts in vivo. MATERIALS AND METHODS: SW480 cells inoculated subcutaneously into NU/NU mice were treated with anti-IL6R and tumor histology and growth-related signaling were subsequently estimated by hematoxylin and eosin and immunohistochemical staining. RESULTS: Tumor growth was inhibited by anti-IL6R treatment at dosages of both 0.1 and 1.0 mg/kg. Tumor cells had invaded into surrounding tissues in untreated mice, while there was no invasion of tumors in the IL6R antibody-treated mice. The expression of Ki-67, signal transducer and activator of transcription protein 3 (STAT3) and phosphor-extracellular signal-regulated kinase 1 and 2 (ERK1/2) were suppressed in anti-IL6R-treated tumors. CONCLUSION: IL6R antibody inhibited tumor growth and invasiveness in vivo by suppressing the expression of Ki-67, STAT3 and phosphor-ERK1/2. The results imply that the anti-IL6R may be a promising targeted drug for CRC.

Differential whole-genome doubling and homologous recombination deficiencies across breast cancer subtypes from the Taiwanese population.

Whole-genome doubling (WGD) is an early macro-evolutionary event in tumorigenesis, involving the doubling of an entire chromosome complement. However, its impact on breast cancer subtypes remains unclear. Here, we performed a comprehensive and quantitative analysis of WGD and its influence on breast cancer subtypes in patients from Taiwan and consequently highlight the genomic association between WGD and homologous recombination deficiency (HRD). A higher manifestation of WGD was reported in triple-negative breast cancer, conferring high chromosomal instability (CIN), while HER2 + tumors exhibited early WGD events, with widely varied CIN levels, compared to luminal-type tumors. An association of higher activity of de novo indel signature 2 with WGD and HRD in Taiwanese breast cancer patients was reported. A control test between WGD and pseudo non-WGD samples was further employed to support this finding. The study provides a better comprehension of tumorigenesis in breast cancer subtypes, thus assisting in personalized treatment.

Evolutionary Trajectories and Genomic Divergence in Localized Breast Cancers after Ipsilateral Breast Tumor Recurrence.

The evolutionary trajectories that drive clinical and therapeutic consequences in localized breast cancers (BCs) with ipsilateral breast tumor relapse (IBTR) remain largely unknown. Analyses of longitudinal paired whole-exome sequencing data from 10 localized BC patients with IBTR reveal that, compared to primary breast tumors, homologous recombination (HR) deficiency, inactivation of the HR pathway, chromosomal instability, and somatic driver mutations are more frequent. Furthermore, three major models of evolution in IBTR are summarized, through which relative contributions of mutational signatures shift, and the subclonal diversity expansions are shown. Optimal treatment regimens are suggested by the clinically relevant molecular features, such as HR deficiency (20%) or specific alterations (30%) with sensitivity to available FDA-approved drugs. Finally, a rationale for the development of the therapeutic management framework is provided. This study sheds light on the complicated evolution patterns in IBTR and has significant clinical implications for future improvement of treatment decisions.

The effect of Longan seed polyphenols on colorectal carcinoma cells.

BACKGROUND: Polyphenol-rich longan seed extract (LSP) is a free radical scavenger and antioxidant. However, the effect of LSP on the growth of human colorectal carcinoma cells (CRC) has not yet been evaluated. MATERIALS AND METHODS: Polyphenols of longan seeds were extracted and measured by colorimetry. Four CRC cell lines (Colo 320DM, SW480, HT-29 and LoVo) were treated with LSP and assessed for viability by trypan blue exclusion, for cell cycle distribution by flow cytometry, for apoptosis by annexin V labelling and for changes in the levels of proteins involved in cell cycle control or apoptosis by immunoblotting. RESULTS: Total phenol content of LSP was 695 mg g(-1) and total flavonoids were 150 mg g(-1). LSP inhibited the proliferation (25 microg mL(-1)-200 microg mL(-1)) of Colo 320DM, SW480 and HT-29, but not LoVo. LSP inhibited the proliferation by blocking cell cycle progression during the DNA synthesis phase and inducing apoptotic death. Western blotting indicated that LSP blocks the S phase, reducing the expression of cyclin A and cyclin D1. Colo 320DM and SW480 treated with LSP also showed the activation of caspase 3 and increased Bax : Bcl-2 ratio. CONCLUSION: LSP induces S phase arrest of the cell cycle and apoptotic death in three CRC cell lines. The results indicate that LSP is a potential novel chemoprevention and treatment agent for colorectal cancer.

Longan flower extract inhibits the growth of colorectal carcinoma.

Longan flower extract (LFE) has been shown to exhibit free radical scavenging ability and anti-inflammatory effects. However, the effect of LFE treatment on the growth of colorectal cancer cells has not been evaluated. This study investigated the effect of LFE on two colorectal cancer cell lines, SW-480 and Colo 320DM, and the possible mechanisms involved. LFE-treated cells were assessed for viability by trypan blue exclusion, for in vitro tumorigenesis by seeding cells in soft agar to allow anchorage independent growth, for cell cycle distribution by flow cytometry, for loss of mitochondrial membrane potential by rhodamine 123 staining, for increased apoptosis by DNA fragmentation assay, and for changes in the levels of proteins involved in cell cycle control and apoptosis by immunoblotting. LFE (25-400 microg/ml) could inhibit proliferation in a dose- and time-dependent manner. The cell cycle of both LFE-treated cell lines showed obvious S phase block. Western blotting further showed the S phase block in these two cell lines was mainly due to cyclin E accumulation and cyclin A decrease. LFE treatment increased rhodamine 123-negative cells and DNA fragmentation in Colo 320DM cells but not in SW480 cells. Increased levels of the apoptosis activation protein, caspase 3, were also found in Colo 320DM cells. The activation of caspase 3 in LFE-treated SW480 cells was not significant. The caspase 3 activation in Colo 320DM cells by LFE was mediated by the suppression of Bcl-2 protein levels. LFE treatment could inhibit the proliferation and malignancy of colorectal cancer cell lines and was associated with S phase block of the cell cycle. An apoptotic mechanism induced by LFE involving a loss of mitochondrial membrane potential and caspase 3 activation was found in Colo 320DM cells but not in SW480 cells. The results of this study indicate that LFE has potential to be developed as a novel functional food or chemopreventive agent for colorectal cancer.

Electroacupuncture combined with acarbose improves insulin sensitivity via peroxisome proliferator-activated receptor γ activation and produces a stronger glucose-lowering effect than acarbose alone in a rat model of steroid-induced insulin resistance.

BACKGROUND: Previous studies have reported that electroacupuncture (EA) induces a glucose-lowering effect by improving insulin resistance (IR) and reduces plasma free fatty acid (FFA) levels in rats with steroid-induced insulin resistance (SIIR). In addition, EA can activate cholinergic nerves and stimulate endogenous opioid peptides to lower plasma glucose in streptozotocin-induced hyperglycemic rats. The aim of this study was to investigate the glucose-lowering effects of 15 Hz EA at bilateral ST36 in combination with acarbose (ACA). We hypothesized that EA combined with ACA would produce a stronger glucose-lowering effect than ACA alone. METHODS: In this study, normal Wistar rats and SIIR rats were randomly divided into two groups: ACA and ACA + EA. To explore the potential mechanisms underlying the glucose-lowering effect, plasma FFA/insulin and insulin transduction signal pathway proteins were assayed. RESULTS: Combined ACA + EA treatment had a greater glucose-lowering effect than ACA alone in normal Wistar rats (-45% ± 3% vs -19% ± 3%, p < 0.001) and SIIR model rats (-43% ± 2% vs -16% ± 6%, p < 0.001). A significant reduction in plasma FFA levels, improvement in homeostatic model assessment of IR (HOMA-IR) index (-48.9% ± 4.0%, p < 0.001) and insulin sensitivity index (102% ± 16.9%, p < 0.001), and significant increases in insulin receptor substrate 1, glucose transporter 4, and peroxisome proliferator-activated receptor γ protein expressions in skeletal muscle, were also observed in the ACA + EA group of SIIR rats. CONCLUSION: Combined EA and ACA therapy had a greater glucose-lowering effect than ACA monotherapy; this combined therapy could be more effective at improving IR in SIIR rats, which may be related to a reduction in plasma FFA levels and an elevation of insulin signaling proteins. Whether this combined therapy has an effect in type 2 diabetes mellitus (T2DM) patients still needs to be explored.

Mechanisms of grape seed procyanidin-induced apoptosis in colorectal carcinoma cells.

BACKGROUND: Grape seed procyanidins (GSP) can inhibit cell proliferation and tumorigenesis, and induce apoptosis in human breast, prostate, skin and colorectal carcinoma cell lines. MATERIALS AND METHODS: In order to study the mechanism of apoptosis, four colorectal cell lines, HT-29, SW-480, LoVo and Colo 320DM, were used. GSP-treated cells were assessed for viability by trypan blue exclusion, for loss of mitochondrial membrane potential by rhodamine 123 staining, for increased apoptosis by annexin V labeling, and for changes in the levels of proteins involved in apoptosis by immunoblotting. RESULTS: GSP had no significant pro-apoptotic effect on the Colo 320DM cell line. In HT-29, SW-480 and LoVo cells, GSP (12.5-50 mg/l) inhibited proliferation in a dose-dependent manner. In these three lines, GSP treatment increased the proportion of rhodamine 123-negative cells and annexin V-positive cells, while immunoblotting revealed increased levels of apoptosis activation protein, caspase-3 and the cleavage fragment of PARP (a caspase-3 substrate), but the level of Bcl-2 did not change. CONCLUSION: GSP inhibited the proliferation of some colorectal carcinoma cell lines and was associated with an apoptotic mechanism involving a loss of mitochondrial membrane potential and caspase-3 activation in these cells.