Cell Line LoVo Research Articles

Upregulation of microRNA-383 inhibits the proliferation, migration and invasion of colon cancer cells.

Increasing evidence demonstrates that microRNAs (miRNAs/miRs), a type of non-coding small RNA, can regulate tumor cell migration, invasion and metastasis, and may therefore serve a major function in the occurrence and development of tumors. The present study investigated the effect of miR-383 on the proliferation, migration and invasion of colon cancer HT-29 and LoVo cell lines. The expression of miR-383 in colon cancer and adjacent non-tumor tissues was examined by reverse transcription-quantitative polymerase chain reaction. MiR-383 upregulation was stimulated by transfection with a miR-383 mimic. Cell proliferation was measured with MTT and colony formation assays, and cell migration and invasion potential were examined by Transwell chamber assays. A proliferating-inducing ligand (APRIL), myeloid cell leukemia-1 and cyclooxygenase-2 protein expression was analyzed by western blotting. The expression of miR-383 was decreased in colon cancer tissues compared with adjacent non-tumor tissues (P<0.05). Transfection with a miR-383 mimic suppressed proliferation and inhibited cell migration and invasion in HT-29 and LoVo colon cancer cell lines. Overexpression of miR-383 in HT-29 and LoVo cells resulted in the suppression of APRIL protein expression. In conclusion, miR-383 was downregulated in colon cancer. The upregulation of miR-383 inhibited proliferation, migration and invasion of colon cancer cells, potentially through the regulation of target gene APRIL.

Synthesis and biological evaluation of acyl derivatives of hydroxyflavones as potent antiproliferative agents against drug resistance cell lines.

The synthesis of hydroxyflavone derivatives is described. The acyl derivatives of 3-, 6-, 7-hydroxyflavones (compounds 2, 4, 6, respectively) and chrysin (5,7-dihydroxyflavone, 7) were obtained in high yields and evaluated in vitro for their cytotoxic activity against several cancer cell lines of different origin: MCF-7 (breast cancer), A549 (nonsmall cell lung cancer), MES-SA (uterine sarcoma), LoVo (colon cancer), drug-resistant human cancer cells (MES-SA/DX5, LoVo/DX) and also towards non-cancer cell line MCF-10A (normal breast epithelial cells). The flavones modified with acyl group showed higher antiproliferative activity than free hydroxyflavones. The highest activity was noted for 3-acetoxyflavone (2), which proved active against LoVo, LoVo/DX, and MES-SA cell lines (IC50 from 4.7 μM to 7.8 μM, respectively). The highest ability to overcome the barrier of resistance (resistance index=0.82) against the drug-resistant MES-SA/DX5 cells compared to the parental drug-sensitive MES-SA cell line was found for 7-acetoxyflavone (6).

Circadian gene hCLOCK contributes to progression of colorectal carcinoma and is directly regulated by tumor‑suppressive microRNA‑124.

An abundance of studies has demonstrated that disruption of circadian rhythms is one of the factors that may contribute to the initiation and development of human colorectal carcinomas (CRCs). Recently, microRNA-124 has been demonstrated to suppress tumor growth or metastasis of CRCs. However, the mechanisms of cross-talk between microRNA-124 (miR-124) and circadian rhythms in the regulation of CRCs are poorly understood. The present study demonstrated that the protein expression levels of human circadian locomoter output cycles protein kaput (hCLOCK) is significantly increased, while miR-124 is attenuated in high-grade human CRC tissues and in the more invasive colorectal cancer cell lines SW620 and LOVO. It was further demonstrated that hCLOCK is a direct target of miR-124. Upregulation of miR-124 significantly inhibited hCLOCK expression in LOVO cells, and consequently inhibited its promoting effects on the proliferation and migration of LOVO cells. In conclusion, these data revealed that hCLOCK serves an enhancing role, whereas mir-124 serves a suppressive role, in human CRC. Attenuation of miR-124, of which hCLOCK is a direct target, leads to increased hCLOCK expression and disruption of circadian rhythms in CRC.

Overexpression of Rictor protein in colorectal cancer is correlated with tumor progression and prognosis.

In order to understand the clinical significance of rapamycin-insensitive companion of mammalian target of rapamycin (Rictor) in colorectal cancer (CRC), 62 CRC tissue samples excised during operations were evaluated by immunohistochemistry. Analysis of the association between the expression level of Rictor protein and clinicopathological parameters demonstrated that the expression level of Rictor in CRC tissues was significantly higher than that in paracarcinoma tissues (P<0.0001). In cellular experiments, this result was further confirmed by comparing differences in Rictor expression between the CRC cell lines HCT116, SW480 and LoVo, and the human normal liver cell line HL-7702. It was also noticed that the expression of Rictor was associated with Dukes stage, lymphatic metastasis and prognosis, as determined by χ2 test, Kaplan-Meier analysis and log-rank test. These results suggest that Rictor may be a novel target for the treatment and prognostic assessment of CRC patients in the future.

P52 confers resistance to oxaliplatin in oxaliplatin resistant colon cancer

Objective To assess the role of p52 in resistance to oxaliplation in colon cancer. Methods Colon cancer cell lines SW480, LoVo and resistant cells (SW480/L-OHP, LoVo/L-OHP) were cultured. The inhibiting rates of SW480, LoVo cells and resistant cells by oxaliplatin were determined by cell counting kit-8 (CCK-8) assay. Western blotting was applied to assess induced p52 expression after cultured with oxaliplatin contained medium for 24 h in SW480 cells. We adopted chromatin immunoprecipitation (CHIP) to validate translational regulation of B cell lymphoma/leukemia-2 (bcl-2) by p52. SW480/L-OHP cells were cultured with oxaliplatin contained medium for 24 h after tranfected with siP52, then stained with Annexin V/propidium iodide (PI) in the detection of apoptosis cells by flow cytometry. Total protein was extracted and Western blotting was used to detect the expression of bcl-2, p52 after transfected with small interfering RNA (siRNA) targeting p52. Results Induced p52 expression was seen in SW480 cells. Translational regulation of bcl-2 by p52 was validated by CHIP assays. Down-regulation of bcl-2 was induced by sip52. The proportion of Annexin V/PI positive cells elevated in sip52 silenced SW480/L-OHP cells after treated with oxaliplatin for 24 h. Conclusion p52 confers resistance to oxaliplatin in oxaliplatin resistant colorectal cancer by inhibiting apoptosis. Key words: Colorectal cancer; Oxaliplatin; P52

α7 nicotinic acetylcholine receptor in tumor-associated macrophages inhibits colorectal cancer metastasis through the JAK2/STAT3 signaling pathway.

Considerable evidence has implied that α7 nicotinic receptor subtypes play an important role in chronic inflammatory and neuropathic pain signaling. The aim of the present study was to determine the role of endogenous α7nAChR signaling in tumor-associated macrophages (TAMs) in human colorectal cancer (CRC) metastasis and prognosis. α7nAChR expression in primary tumor cells and adjacent stroma cells especially in TAMs in 51 CRC patients was observed. Using a human monocyte THP-derived macrophages (TMs) with α7nAChR-siRNA knockdown (TMα7−/−) and a CRC cell Transwell co-culture model, the migration and invasion of two CRC cells, LoVo and SW620, were determined. Western blotting was carried out to investigate the expression of multiple molecules involved in the NF-κB, STAT3, PI3K signaling pathways in mimic TAMs, i.e., TMs exposed to in-direct LoVo cell stimulation. A nicotinic α7 receptor antagonist [α-bungarotoxin (α-Btx)] and three pharmaceutical inhibitors: AG490 (JAK2/STAT3 inhibitor), LY294002 (PI3K inhibitor) and Bay 11–7082 (NF-κB inhibitor) were applied to evaluate whether these signaling pathways were associated with the enhanced migration of CRC cells when co-cultured with α7nAChR knockdown TMs. The results revealed that the expression of α7nAChR in TAMs differed in patients. However, CRC patients who had a high incidence of hepatic metastasis showed no or low expression of α7nAChR in TAMs. TMs with α7nAChR-siRNA knockdown (TMα7−/−) significantly enhanced the migration and invasion of the two CRC cell lines LoVo and SW620. α7nAChR knockdown in TMs significantly downregulated phosphorylation of STAT3, PI3K p85 and NF-κB p65 after co-culturing with LoVo cells. Inhibition of JAK2/STAT3 prevented the TMα7−/−-enhanced migration of LoVo cells. α7nAChR expressed in TAMs in human CRC patients plays an important role in preventing metastasis and could be a prognostic marker in CRCs, which may be regulated by the JAK2/STAT3 signaling pathway.

Upregulation of Yes-associated protein and transcriptional co-activator with PDZ-binding motif influences the behavior of LOVO human colon adenocarcinoma cells.

The present study aimed to investigate the role of Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ) in the LOVO human colon adenocarcinoma cell line and explore the underlying mechanisms. First, the expression levels of YAP and TAZ were detected in LOVO cells using reverse-transcription quantitative PCR, and the results suggested that YAP and TAZ were faintly expressed in LOVO cells. To investigate the exact role of YAP and TAZ in LOVO cells, stable YAP- and/or TAZ-overexpressing LOVO cell lines were established using YAP and/or TAZ expression plasmids. An MTT assay and flow cytometry were used to assess cell proliferation and apoptosis, respectively. The results indicated that compared with the control, YAP or TAZ overexpression significantly increased the proliferation ability of LOVO cells, while apoptosis was significantly decreased. Furthermore, the expression of the tumor-associated proteins connective tissue growth factor and cysteine-rich angiogenic inducer 61, which have critical roles in facilitating cancer cell proliferation, migration and invasion, were found to be upregulated following upregulation of YAP and TAZ. In addition, the expression of cell apoptosis-associated protein B-cell lymphoma 2 (Bcl-2) was significantly increased, while Bcl-2-associated X protein and caspase-3 were inhibited by YAP or TAZ overexpression. All of these effects were amplified when YAP and TAZ were co-overexpressed. In conclusion, YAP and TAZ function as tumor promoters in human colon carcinoma, and upregulation of YAP and TAZ influences the behavior of LOVO colon adenocarcinoma cells via regulating tumor-associated gene expression.

MiR-378 suppresses the proliferation, migration and invasion of colon cancer cells by inhibiting SDAD1

BackgroundMicroRNAs (miRNAs) play important roles in the growth and metastasis of colon cancer. It is known that one set of miRNAs are dysregulated in colon cancer cells, but the mechanism of their role in cancer development is still largely unknown. Our study focuses on the role of miR-378 in colon cancer cells.MethodsHuman colon cancer tissues and adjacent non-tumor tissues were collected from patients diagnosed in pathological examinations. In addition, human colon cancer cell lines LoVo, CaCo2, SW1116, SW480 and HCT-116, and a normal colonic mucosa cell line NCM460 were included. Quantitative RT-PCR was used to detect the miR-378 level in the clinical tissues and cell lines. In SW480 and HCT-116, miR-378 was artificially overexpressed or suppressed. Cell viability and proliferation were measured using MTT and colony formation assays, and apoptosis was detected via annexin V-PI staining and flow cytometry analysis. The transwell technique was applied to detect the migration and invasion of the colon cancer cells, and their epithelial–mesenchymal transition (EMT) was evaluated by detecting EMT-associated markers using Western blotting. Bioinformatics methods were used to predict the potential targets of miR-378, and luciferase reporter assays were performed to conform the direct binding between miR-378 and its target mRNA. The activity of the Wnt/β-catenin pathway was evaluated by detecting the key factors through Western blotting.ResultsWe found that miR-378 expression was low in colon cancer tissues and cell lines. Overexpression of miR-378 not only inhibits the proliferation of colon cancer cells in vitro by inducing apoptosis, but also inhibits migration and invasion by inhibiting the EMT of colon cancer cells. SDAD1 is a direct target gene of miR-378, and knockdown of SDAD1 suppresses the proliferation, migration and invasion of colon cancer cells. We also confirmed that miR-378 alleviated the malignant phenotypes of colon cancer cells by inhibiting the Wnt/β-catenin pathway.ConclusionmiR-378 inhibits the proliferation, migration and invasion of colon cancer cells by targeting SDAD1, defining miR-378 as a potential target for the diagnosis and treatment of colon cancer.

Abstract 5840: Radiosensitization with the c-MET inhibitor crizotinib in KRAS mutant colorectal cancer

Abstract Background: KRAS mutant colorectal cancers (CRC) are resistant to many targeted therapies including cetuximab. Novel molecular targets for KRAS mutant tumors may enhance the efficacy of chemoradiation. C-MET plays important roles in treatment resistance, tumor invasion, and metastasis. In this study, we used a small molecule inhibitor of c-MET, crizotinib in cetuximab resistant mutant KRAS driven CRC cell lines and assessed radiosensitization. Methods: To test the effect of c-MET inhibition on CRC cells we used the KRAS mutant cell lines HCT116, DLD1, and LoVo. Colony formation assays were performed to assess the effects of crizotinib and cetuximab. Immunoblot analysis was used to determine the effect of crizotinib on c-MET and downstream pathways including ERK and AKT phosphorylation. We then selected doses of crizotinib below the IC50 and assessed clonogenic survival with radiation. To study potential mechanisms of radiosensitization cell cycle analysis was performed using flow cytometry. The effect of c-MET inhibition on cellular function was assessed using cell migration assays. Results: We first performed a series of clonogenic survival assays with crizotinib and cetuximab to determine the IC50 for each cell line. As expected, the KRAS mutant cell lines LoVo, HCT116, and DLD1 were resistant to cetuximab (surviving fraction greater than 95% at 100 μg/ml). These cell lines were sensitive to the c-MET inhibitor crizotinib with IC50 values of 14.4 nM for LoVo, 316 nM for HCT166, and 217 nM for DLD1. Immunoblot analysis showed that crizotinib at concentrations near the IC50 for each cell line attenuated c-MET phosphorylation and downstream signaling pathways including ERK and AKT. Crizotinib further blocked radiation induced c-MET phosphorylation and attenuated activation of downstream signaling pathways. We then performed a series of clonogenic survival assays to study the radiosensitizing potential of crizotinib. Pretreatment with crizotinib for 24 hours radiosensitized LoVo and DLD1 cell lines with enhancement ratios of 1.66 and 1.25, respectively. Interestingly, treatment with crizotinib for 1 hour prior to radiation had only modest dose enhancement, suggesting that prolonged exposure to crizotinib is required for optimal radiosensitization. Cell cycle analysis revealed minimal G1 arrest with crizotinib. Additionally, crizotinib completely blocked HGF and EGF induced cell migration. Conclusions: Inhibition of c-MET with crizotinib effectively sensitizes cetuximab resistant KRAS mutant CRC cell lines to radiation. Given the important role c-MET plays in treatment resistance, crizotinib has the potential to improve the outcome of patients with locally advanced rectal cancer undergoing radiation therapy. Citation Format: Kyle C. Cuneo, Himabindu Kurapati, Ranjit Mehta, Theodore S. Lawrence, Mukesh K. Nyati. Radiosensitization with the c-MET inhibitor crizotinib in KRAS mutant colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5840. doi:10.1158/1538-7445.AM2017-5840

Dexamethasone affects cell growth/apoptosis/chemosensitivity of colon cancer via glucocorticoid receptor α/NF-κB.

Glucocorticoids are effective to treat lymphoma and leukemia. Their effect in colon cancer remains far from clear. Here, we found that glucocorticoid receptor (GR) α protein level was dramatically lower in colon cancer than in lymphoma. Colon cell lines LoVo and HCT116 were GRα-rich and GRα was not detectable in HT29 or SW480. Dexamethasone significantly inhibited cell growth of GRα-rich cell lines and did not significantly affect GRα-negative cell lines. Dexamethasone induced apoptosis and increased chemosensitivity of GRα-rich cell lines. Knockdown of GRα significantly attenuated dexamethasone effects on cell growth, apoptosis and chemosensitivity. NF-κB p65 significantly correlated with GRα in colon cancer samples. Dexamethasone decreased NF-κB p65 activity. Knockdown of NF-κB p65 increased apoptosis. Our data demonstrate GRα protein level is dramatically lower in colon cancer than in lymphoma. Dexamethasone inhibits cell growth, induces apoptosis and enhances chemosensitivity in colon cancer, at least partly, via GRα and NF-κB.

High expression of GPR116 indicates poor survival outcome and promotes tumor progression in colorectal carcinoma.

Previous studies have found that G-protein-coupled receptor 116 (GPR116) is a regulator of breast cancer metastasis. However, the role of GPR116 in colorectal carcinoma (CRC) carcinogenesis and progression is unknown. In this study, We found GPR116 expression was significantly up-regulated in CRC specimens compared with corresponding non-cancerous tissues. Increased GPR116 expression in CRC was correlated with histological differentiation and distant metastasis. In addition, high expression of GPR116 was significantly associated with poor overall survival of CRC patients, which was also confirmed by GSE14333, GSE17536 and GSE33113 datasets from the Gene Expression Omnibus (GEO). Furthermore, we demonstrated that the ability of proliferation and invasion of CRC cell lines HCT116 and LOVO was markedly reduced after transfected with siRNA-GPR116. Meanwhile, GPR116 may drive EMT in CRC cells through AKT/EKR signaling pathway, resulting in metastasis. Thus, GPR116 may be a novel reliable prognostic indicator and a risk factor in CRC progression.

Connexin 43 enhances oxaliplatin cytotoxicity in colorectal cancer cell lines.

Oxaliplatin, a platinum-based chemotherapeutic agent, is an important first-line drug in the treatment of colorectal cancers, but drug resistance causes treatment failure. It has been reported that gap junctional communication can enhance the cytotoxicity of platinum drugs. The gap junction formed of connexin proteins provides a direct pathway for electrical and metabolic cell-cell interaction. The voltage-dependent gating of gap junction allows small hydrophilic molecules and ions to permeate to adjacent cells. Connexin 43 is a diagnostic marker for cancer therapy and the predominant connexin isoform in many cell types. The purpose of this study was to investigate the role of connexin 43 in oxaliplatin activity by using colorectal cancer cell lines. LoVo and HCT116 cell lines were used for analysis. Connexin 43 expression was confirmed by western blot and immunocytochemistry. MTT, western blot, "Parachute" dye-coupling assays and reactive oxygen species measurement were used to detect cytotoxicity and the inhibition of connexin 43 expression induced by oxaliplatin. Results showed that connexin 43 enhanced oxaliplatin cytotoxicity through gap junctional communication function and high concentration of oxaliplatin inhibited connexin 43 expression to counteract its cytotoxicity. This study suggested that connexin 43 could be considered a molecular target of oxaliplatin activity in colorectal cancer.

Novel proapoptotic agent SM-1 enhances the inhibitory effect of 5-fluorouracil on colorectal cancer cells in vitro and in vivo.

5-Fluorouracil (5-FU) is one of the most important agents used to treat colorectal cancer. However, the therapeutic effect of 5-FU on colon cancer is limited. SM-1 is a novel type of proapoptotic agent that directly activates procaspase-3 to caspase-3, leading to apoptosis in human cancer cells. The aim of the present study was to evaluate the antitumor effects of 5-FU in combination with SM-1. The human colorectal cancer cell lines HCT116 and LoVo were cultured in the presence of SM-1 and 5-FU. The combination of SM-1 and 5-FU treatment exhibited increased proliferation inhibitory effects compared with 5-FU treatment alone in HCT116 and LoVo cells, as determined using an MTT assay. SM-1 significantly decreased the half-maximal inhibitory concentration of 5-FU from 8.07±0.49 to 2.55±0.41 µmol/l in HCT116 cells, and from 7.90±0.98 to 3.14±0.81 µmol/l in LoVo cells. Similarly, the apoptotic activity was increased to 47.95 and 35.19% in HCT116 and LoVo cells, respectively, as determined using Annexin V/propidium iodide staining and flow cytometry. The combination of SM-1 and 5-FU treatment led to significantly increased caspase-3 activity compared with either compound alone. The reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis revealed the downregulation of B-cell lymphoma 2 and Survivin, and the upregulation of apoptosis regulator Bcl-2-associated X protein and cleaved poly (ADP-ribose) polymerase in HCT116 and LoVo cells. In addition, RT-qPCR identified downregulation of X-linked inhibitor of apoptosis protein mRNA. 5-FU and SM-1 treatment in combination increased tumor proliferation inhibition in HCT116 and LoVo xenograft mouse models of colorectal cancer, compared with SM-1 or 5-FU treatment alone. SM-1 significantly enhanced the antitumor activity of 5-FU in colorectal cancer. These improved effects were due to increased activity of the apoptotic signaling pathway.

Overexpression of NOX4 predicts poor prognosis and promotes tumor progression in human colorectal cancer.

NADPH oxidase 4 (NOX4), a major source of reactive oxygen species (ROS) production, has been increasingly reported to be involved in tumorigenesis and/or tumor progression, but limited data are available regarding the role of NOX4 in colorectal carcinoma (CRC). We retrieved six independent investigations from Oncomine database and found that NOX4 is highly expressed in CRC tissues compared with corresponding normal controls. Similar results were also found in clinical specimens at both mRNA and protein levels. Immunohistochemical analysis indicated that NOX4 overexpression was highly correlated with T classification, N classification, distant metastasis, and poor prognosis of CRC patients, which was also confirmed by GSE14333 and GSE17536 datasets from the Gene Expression Omnibus. Furthermore, we demonstrated that when NOX4 expression was knocked down by siRNAs, cell proliferation, cell-cycle and apoptosis, migration and invasion were significantly altered in CRC cell lines HCT116 and LOVO. Meanwhile, NOX4 promoted cancer cell proliferation and apoptosis, migration and invasion by regulating the expression of relevant genes. By these approaches we aim to elucidate NOX4 may be a reliable prognostic factor or therapeutic target in CRC.

Transcription-dependent radial distribution of TCF7L2 regulated genes in chromosome territories.

Human chromosomes occupy distinct territories in the interphase nucleus. Such chromosome territories (CTs) are positioned according to gene density. Gene-rich CTs are generally located in the center of the nucleus, while gene-poor CTs are positioned more towards the nuclear periphery. However, the association between gene expression levels and the radial positioning of genes within the CT is still under debate. In the present study, we performed three-dimensional fluorescence in situ hybridization experiments in the colorectal cancer cell lines DLD-1 and LoVo using whole chromosome painting probes for chromosomes 8 and 11 and BAC clones targeting four genes with different expression levels assessed by gene expression arrays and RT-PCR. Our results confirmed that the two over-expressed genes, MYC on chromosome 8 and CCND1 on chromosome 11, are located significantly further away from the center of the CT compared to under-expressed genes on the same chromosomes, i.e., DLC1 and SCN3B. When CCND1 expression was reduced after silencing the major transcription factor of the WNT/β-catenin signaling pathway, TCF7L2, the gene was repositioned and mostly detected in the interior of the CT. Thus, we suggest a non-random distribution in which over-expressed genes are located more towards the periphery of the respective CTs.

Triterpenoid Acids as Important Antiproliferative Constituents of European Elderberry Fruits

ABSTRACTIn Europe, both the fruits and flowers of Sambucus nigra L. have been used against cold, as well as laxative, diaphoretic, and diuretic remedies. There are also a number of commercially available food products that contain elderberry juice, puréed or dried elderberries. Recent comprehensive literature data on pharmacology and chemistry of Sambuci fructus have encouraged us to screen extracts with different polarities from this plant material against cancer cell lines. The cytotoxic activity of the ethyl acetate and aqueous acetone extracts from elderberries as well as detected triterpenoids on human colon adenocarcinoma cell line (LoVo) and human breast cancer cell line (MCF-7) was investigated by sulforhodamine B assay. Moreover, cell migration assay was conducted for triterpenoid fraction and pure compounds. Aqueous acetone extract possessed much lower IC50 value in cancer cell lines compared to ethyl acetate extract. The latter manifested high cytotoxicity against studied cell lines, suggesting that nonpolar compounds are responsible for the cytotoxic activity. Indeed, the phytochemical analysis revealed that ursolic and oleanolic acids are the main triterpenoids in the mentioned extract of which ursolic acid showed the highest activity with IC50 values of 10.7 µg/mL on MCF-7 and 7.7 µg/mL on LoVo cells.

Strawberry-Tree Honey Induces Growth Inhibition of Human Colon Cancer Cells and Increases ROS Generation: A Comparison with Manuka Honey.

Honey is a natural product known to modulate several biological activities including cancer. The aim of the present study was to examine the phytochemical content and the antioxidant activity of Strawberry tree (Arbutus unedo) honey (STH) and its cytotoxic properties against human colon adenocarcinoma (HCT-116) and metastatic (LoVo) cell lines in comparison with Manuka (Leptospermum scoparium) honey (MH). Several unifloral STH and MH were analyzed for their phenolic, flavonoid, amino acid and protein contents, as well as their radical scavenging activities. STH from the Berchidda area showed the highest amount of phenolic, flavonoid, amino acid and protein content, and antioxidant capacity compared to MH. Both STH and MH induced cytotoxicity and cell death in a dose- and time-dependent manner in HCT-116 and LoVo cells, with less toxicity on non-cancer cells. Compared to MH, STH showed more effect at lower concentrations on HCT-116 and LoVo cells. In addition, both honeys increased intracellular reactive oxygen species (ROS) generation. In HCT-116 cells, STH and MH induced similar ROS production but in LoVo cells STH induced a higher percentage of ROS compared to MH. Our results indicate that STH and MH can induce cell growth inhibition and ROS generation in colon adenocarcinoma and metastatic cells, which could be due to the presence of phytochemicals with antioxidant properties. These preliminary results are interesting and suggest a potential chemopreventive action which could be useful for further studies in order to develop chemopreventive agents for colon cancer.

MTA3 regulates malignant progression of colorectal cancer through Wnt signaling pathway.

MTA3 overexpression has been implicated in carcinogenesis. The aim of the present study was to explore the clinical significance and biological roles of MTA3 in human colorectal cancer and colorectal cancer cells. A total of 80 cases of colorectal cancer tissues were examined by immunohistochemistry for MTA3 protein expression. We analyzed the relationship between MTA3 and clinical factors and the results showed that MTA3 was overexpressed in 51.25% (41/80) cancer cases. There was significant associations between MTA3 overexpression and advanced TNM stage (p = 0.0086) and Ki67 index (p = 0.001). We overexpressed MTA3 in LoVo cells and depleted its expression in HCT15 cells. The results showed that MTA3 promoted cancer cell proliferation, invasion, migration, and cell cycle progression, and inhibited 5-fluorouracil-induced apoptosis in LoVo cell line. MTA3 depletion in HCT15 cell line showed the opposite effects. In addition, we found that MTA3 positively regulated cell cycle proteins including cyclin D1 and cyclin E. It also upregulated Bcl2 and downregulated Bax expression. Furthermore, we found that MTA3 could activate Wnt signaling pathway by upregulating Wnt target proteins. Our results demonstrated that MTA3 overexpression contributes to colorectal cancer carcinogenesis, progression, and chemoresistance. MTA3 could serve as a potential therapeutic target in colorectal cancer.

Bufalin reverses acquired drug resistance by inhibiting stemness in colorectal cancer cells

Drug resistance is an obstacle to chemotherapy in tumor patients. Recent studies have shown that the high stemness of cancer cells may be induced by chemotherapeutic drugs, which is correlated with drug resistance. In the present study, we investigated the effects of bufalin on the stemness of colorectal cancer. We found that cisplatin could induce high stemness through the tumorsphere formation assay in vitro and in vivo in the colorectal cancer cell lines HCT116 and LoVo. In addition, cisplatin-treated tumorsphere cells showed drug-resistant properties. These results suggested that acquired drug resistance induced by cisplatin in colorectal cancer cells occurred via high stemness. On assessing the effects of bufalin, a traditional Chinese medicine monomer, we found that it could reverse the high stemness and drug resistance induced by cisplatin in colorectal cancer. These findings suggest that bufalin plays an adjuvant role in colorectal cancer chemotherapy and may help reverse acquired drug resistance. These findings may aid in the development of new therapeutic strategies.

New cytotoxic apigenin derivatives from Selaginella doederleinii

75% aqueous ethanol extract from the whole herbs of Selaginella doederleinii was isolated, and two new apigenin derivatives, doederflavones A (1) and B (2), together with ten known compounds (3–12) were characterized. Their structures were assigned by extensive spectroscopic methods including 1D/2D NMR and HR-ESIMS. Compounds 1–6 bear an aryl substituent at the C-8 or C-6 positions in ring A of apigenin skeleton. Compounds 1 and 2 were evaluated for their in vitro cytotoxicity against four human cancer cell lines A549, MCF-7, SMMC-7721, and LoVo, both of which exhibited significant cytotoxicity against A549 with IC50 values of 0.82μmol/L and 1.32μmol/L, respectively.