Apoptotic pathways as a therapeutic target for colorectal cancer treatment

Protection against Oxidative Stress by Coenzyme Q10 in a Porcine Retinal Degeneration Model

Oxidative stress plays an important role in neurodegenerative diseases, including glaucoma. Therefore, we analyzed if the antioxidant coenzyme Q10 (CoQ10), which is also commercially available, can prevent retinal degeneration induced by hydrogen peroxide (H2O2) in a porcine organ culture model. Retinal explants were cultivated for eight days, and H2O2 (500 µM, 3 h) induced the oxidative damage. CoQ10 therapy was applied (700 µM, 48 h). Retinal ganglion cells (RGCs) and microglia were examined immunohistologically in all groups (control, H2O2, H2O2 + CoQ10). Cellular, oxidative, and inflammatory genes were quantified via RT-qPCR. Strong RGC loss was observed with H2O2 (p ≤ 0.001). CoQ10 elicited RGC protection compared to the damaged group at a histological (p ≤ 0.001) and mRNA level. We detected more microglia cells with H2O2, but CoQ10 reduced this effect (p = 0.004). Cellular protection genes (NRF2) against oxidative stress were stimulated by CoQ10 (p ≤ 0.001). Furthermore, mitochondrial oxidative stress (SOD2) increased through H2O2 (p = 0.038), and CoQ10 reduced it to control level. Our novel results indicate neuroprotection via CoQ10 in porcine retina organ cultures. In particular, CoQ10 appears to protect RGCs by potentially inhibiting apoptosis-related pathways, activating intracellular protection and reducing mitochondrial stress.

Anticancer mechanism of coumarin-based derivatives

The structural motif of coumarins is related with various biological activities and pharmacological properties. Both natural coumarin extracted from various plants or a new coumarin derivative synthesized by modification of the basic structure of coumarin, in vitro experiments showed that coumarins are a promising class of anti-tumor agents with high selectivity. Cancer is a complex and multifaceted group of diseases characterized by the uncontrolled and abnormal growth of cells in the body. This review focuses on the anticancer mechanism of various coumarins synthesized and isolated in more than a decade. Isopentenyloxycoumarins inhibit angiogenesis by reducing CCl2 chemokine levels. Ferulin C is a potent colchicine-binding agent that destabilizes microtubules, exhibiting antiproliferative and anti-metastatic effects in breast cancer cells through PAK1 and PAK2-mediated signaling. Trimers of triphenylethylene-coumarin hybrids demonstrated significant proliferation inhibition in HeLa, A549, K562, and MCF-7 cell lines. Platinum(IV) complexes with 4-hydroxycoumarin have the potential for high genotoxicity against tumor cells, inducing apoptosis in SKOV-3 cells by up-regulating caspase 3 and caspase 9 expression. Derivatives of 3-benzyl coumarin seco-B-ring induce apoptosis, mediated through the PI3K/Akt/mTOR signaling pathway. Sesquiterpene coumarins inhibit the efflux pump of multidrug resistance-associated protein. Coumarin imidazolyl derivatives inhibit the aromatase enzyme, a major contributor to estrogen overproduction in estrogen-dependent breast cancer.

HAMLET effect on cell death and mitochondrial respiration in colorectal cancer cell lines with KRAS/BRAF mutations

PURPOSE

Treatment of advanced colorectal cancer (CRC) depends on the correct selection of personalized strategies. HAMLET (Human Alpha-lactalbumin Made LEthal to Tumor cells) is a natural proteolipid milk compound that might serve as a novel cancer prevention and therapy candidate. Our purpose was to investigate HAMLET effect on viability, death pathway and mitochondrial bioenergetics of CRC cells with different KRAS/BRAF mutational status in vitro.

METHODS

We treated three cell lines (Caco-2, LoVo, WiDr) with HAMLET to evaluate cell metabolic activity and viability, flow cytometry of apoptotic and necrotic cells, pro- and anti-apoptotic genes, and protein expressions. Mitochondrial respiration (oxygen consumption) rate was recorded by high-resolution respirometry system Oxygraph-2 k.

RESULTS

The HAMLET complex was cytotoxic to all investigated CRC cell lines and this effect is irreversible. Flow cytometry revealed that HAMLET induces necrotic cell death with a slight increase in an apoptotic cell population. WiDr cell metabolism, clonogenicity, necrosis/apoptosis level, and mitochondrial respiration were affected significantly less than other cells.

CONCLUSION

HAMLET exhibits irreversible cytotoxicity on human CRC cells in a dose-dependent manner, leading to necrotic cell death and inhibiting the extrinsic apoptosis pathway. BRAF-mutant cell line is more resistant than other type lines. HAMLET decreased mitochondrial respiration and ATP synthesis in CaCo-2 and LoVo cell lines but did not affect WiDr cells' respiration. Pretreatment of cancer cells with HAMLET has no impact on mitochondrial outer and inner membrane permeability.

A novel tumour enhancer function of Insulin-like growth factor II mRNA-binding protein 3 in colorectal cancer

CRC cells evolve a variety of strategies to limit or circumvent apoptosis cell death. RNA binding proteins (RBPs) regulate many of the molecular mechanisms that underlie the development of cancer. The insulin-like growth factor II mRNA-binding proteins (IMP) family are oncofoetal RBPs, consisting of IMP1, IMP2 and IMP3, which have an important role in RNA metabolism. IMP3 is highly expressed in colorectal cancer (CRC) tissue, where its expression often correlates with poor prognosis. However, the role of IMP3 in CRC is not fully understood. IMP3 expression was analysed using a public database and by Western blotting and immunohistochemistry in human colon samples derived from patients with sporadic CRC and healthy subjects. To address whether IMP3 controls cancer cell survival, we analysed cell death pathways in in vitro and in vivo experiments after IMP3 downregulation by siRNA or an antisense oligonucleotide. IMP3 was highly expressed in CRC samples compared to normal control tissues. The knockdown of IMP3 enhanced a caspase-independent cell death in CRC cell lines. Furthermore, the treatment of CRC cells with IMP3 siRNA did not alter the expression of GSDMD, GPX-4 and the activated form of RIP3, three key molecules that govern pyroptosis, ferroptosis and necroptosis, respectively. Abrogation of IMP3 in CRC significantly reduced Bcl-2 and Bcl-xL mRNA and was associated with an altered mitochondrial membrane potential that allowed the nuclear migration of the apoptosis-inducing factor (AIF). Moreover, specific immunoprecipitation experiments on CRC human cell lines indicated that IMP3 binds Bcl-2 and Bcl-xL mRNA, suggesting that IMP3 acts as a regulator of the intrinsic apoptotic pathway through the surveillance of anti-apoptotic Bcl mRNA metabolism. Finally, we showed that IMP3 block inhibited the growth of CRC cell lines in vivo after transplantation into immunodeficient mice. Altogether, these data support a novel role for IMP3 in controlling the intrinsic caspase-independent apoptotic pathway in CRC.

Molecular and cellular pathways in colorectal cancer: apoptosis, autophagy and inflammation as key players

BACKGROUND

Colorectal carcinogenesis (CRC) is one of the most aggressive forms of cancer, particularly in developing countries. It accounts for the second and third-highest reason for cancer-induced lethality in women and men respectively. CRC involves genetic and epigenetic modifications in colonic epithelium, leading to colon adenocarcinoma. The current review highlights the pathogenic mechanisms and multifactorial etiology of CRC, influenced by apoptosis, inflammation, and autophagy pathways.

METHODS

We have carried out a selective literature review on mechanisms contributing to the pathogenesis of CRC.

RESULTS

Resistance to senescence and apoptosis of the mesenchymal cells, which play a key role in intestinal organogenesis, morphogenesis and homeostasis, appears important for sporadic CRC. Additionally, inflammation-associated tumorigenesis is a key incident in CRC, supported by immune disruptors, adaptive and innate immune traits, environmental factors, etc. involving oxidative stress, DNA damage and epigenetic modulations. The self-digesting mechanism, autophagy, also plays a twin role in CRC through the participation of LC3/LC3-II, Beclin-1, ATG5, other autophagy proteins, and Inflammatory Bowel Disease (IBD) susceptibility genes. It facilitates the promotion of effective surveillance pathways and stimulates the generation of malignant tumor cells. The autophagy and apoptotic pathways undergo synergistic or antagonistic interactions in CRC and bear a critical association with IBD that results from the pro-neoplastic effects of persistent intestinal inflammation. Conversely, pro-inflammatory factors stimulate tumor growth and angiogenesis and inhibit apoptosis, suppressing anti-tumor activities.

CONCLUSION

Hence, research attempts for the development of potential therapies for CRC are in progress, primarily based on combinatorial approaches targeting apoptosis, inflammation, and autophagy.

The Anticancer Effects of the Pro-Apoptotic Benzofuran-Isatin Conjugate (5a) Are Associated With p53 Upregulation and Enhancement of Conventional Chemotherapeutic Drug Efficiency in Colorectal Cancer Cell Lines

The present study aimed to investigate in-depth a cytotoxic novel benzofuran-isatin conjugate (5a, 3-methyl-N'-(2-oxoindolin-3-ylidene)benzofuran-2-carbohydrazide) with promising potential anticancer activities in colorectal adenocarcinoma HT29 and metastatic colorectal cancer (CRC) SW620 cell lines. Thus, the primary cell events involved in tumorigenicity, tumor development, metastasis, and chemotherapy response were explored. Both CRC cell lines were exposed to different concentrations of Compound 5a and then subjected to real-time cell viability, migration, and invasion assays, colony formation and cytotoxicity assays, and flow cytometry for cell cycle analysis and apoptosis determination. Western blot and RT-qPCR were performed to assess the protein and transcript expression levels of epithelial-mesenchymal transition (EMT), cell cycle, and apoptosis markers. We showed that the Compound 5a treatment exhibited anticancer effects through inhibition of HT29 and SW620 cell viability, migration, and invasion, in a dose-dependent manner, which were associated with the upregulation of the tumor suppressor p53. Compound 5a also inhibited the colony formation ability of HT29 and SW620 cells and reversed EMT markers E-cadherin and N-cadherin expression. CRC cell exposure to Compound 5a resulted in a cell cycle arrest at the G1/G0 phase in HT29 cells and at the G2/M phase in SW620 cells, along with the downregulation of cyclin A1 expression, described to be involved in the S phase entry. Furthermore, Compound 5a-induced apoptosis was associated with the downregulation of the anti-apoptotic Bcl-xl marker, upregulation of pro-apoptotic Bax and cytochrome c markers, and increased mitochondrial outer membrane permeability, suggesting the involvement of mitochondria-dependent apoptosis pathway. In addition, the combination studies of Compound 5a with the main conventional chemotherapeutic drugs 5-fluorouracil, irinotecan, and oxaliplatin showed a more potent cytotoxic effect in both CRC cells than a single treatment. In conclusion, our findings described the interesting in vitro anticancer properties of Compound 5a, shown to have possible antitumor, antimetastatic, and pro-apoptotic activities, with the enhancement of the cytotoxic efficiency of conventional chemotherapeutic drugs. In vivo studies are requested to confirm the promising anticancer potential of Compound 5a for CRC therapy.

The significance of PAK4 in signaling and clinicopathology: A review

P21-activated protein kinases (PAKs) are thought to be at the center of tumor signaling pathways. As a representative member of the group II PAK family, P21-activated protein kinase 4 (PAK4) plays an important role in the development of tumors, with several biological functions such as participating in oncogenic transformation, promoting cell division, resisting aging and apoptosis, regulating cytoskeleton and adhesion, as well as suppressing antitumor immune responses. PAK4 is also crucial in biological processes, including the occurrence, proliferation, survival, migration, invasion, drug resistance, and immune escape of tumor cells. It is closely related to poor prognosis and tumor-related pathological indicators, which have significant clinical and pathological significance. Therefore, this article offers a review of the structure, activation, and biological functions of PAK4 and its clinical and pathological importance. This overview should be of assistance for future research on PAK4 and tumors and provide new ideas for tumor treatment and prognostic evaluation of patients.

Molecular mechanisms of ferroptosis and its role in prostate cancer therapy

Prostate cancer (PCa) is a highly prevalent disease that affects men's health worldwide and is the second most common malignancy in males. Ferroptosis is a novel form of programmed cell death characterized by iron overload and the accumulation of lipid peroxidation, which differs from the regulated cell death modes of necrosis, apoptosis, and autophagy. Substantial progress has been achieved in researching the occurrence and regulatory mechanisms of ferroptosis, which is closely associated with cancer initiation, progression, and suppression and is expected to become a new breakthrough point in the PCa treatment. This review will summarize the mechanisms involved in PCa, and we detail the molecular mechanisms of ferroptosis and its role in PCa treatment.

Anti-Cancerous Potential of Polysaccharides Derived from Wheat Cell Culture

There is a global need to discover effective anti-cancerous compounds from natural sources. Cultivated wheat cells can be a valuable source of non-toxic or low toxic plant-derived polysaccharides. In this study, we evaluated the anti-cancer ability of seven fractions of wheat cell culture polysaccharides (WCCPSs) in the HCT-116 colon cancer cell line. Almost all (6/7) fractions had an inhibitory effect on the proliferation of colon cancer cells, and two fractions (A-b and A-f) had considerable therapeutic indexes. The WCCPS fractions induced cell cycle arrest in the G1 phase and induced different rates of apoptosis (≤48%). Transmission and scanning electron microscopy revealed that WCCPS fractions caused apoptotic changes in the nucleus and cytoplasm, including damage to mitochondria and external morphological signs of apoptosis. In addition, the WCCPSs induced an increase in the levels of Bax, cytochrome c, and caspases 8 and 3, indicating that cell death progressed through intrinsic and extrinsic pathways of apoptosis. Furthermore, some fractions caused a significant decrease of c-Myc, b-catenin, NFkB2, and HCAM (CD 44) levels, indicating enhanced cell differentiation. Thus, for the first time, our results provide a proof of concept of the anti-cancer capacity of WCCPS fractions in colorectal cancer.

Identification of key regulators associated with colon cancer prognosis and pathogenesis

Colon cancer (CC) is the fourth deadliest cancer in the world. New insights into prognostication might be helpful to define the optimal adjuvant treatments for patients in routine clinical practice. Here, a microarray dataset with 30 primary tumors and 30 normal samples was analyzed using GEO2R to find differentially expressed genes (DEGs). Then, DAVID, KEGG, ChEA and X2K were used to analyze DEGs-related Gene Ontology, pathways, transcription factors (TFs) and kinases, respectively. Protein-protein interaction (PPI) networks were constructed using the STRING database and Cytoscape. The modules and hub genes of DEGs was determined through MCODE and CytoHubba plugins, and the expression of hub genes was verified using GEPIA. To find microRNAs and metabolites associated with DEGs, miRTarBase and HMDB were used, respectively. It was found that 233 and 373 genes were upregulated and downregulated in CC, respectively. GO analysis showed that the upregulated DEGs were mainly involved in mitotic nuclear division and cell division. Top 10 hub genes were identified, including AURKB, CDK1, DLGAP5, AURKA, CCNB2, CCNB1, BUB1B, CCNA2, KIF20A and BUB1. Whereas, FOMX1, E2F7, E2F1, E2F4 and AR were identified as top 5 TFs in CC. Moreover, CDK1, CDC2, MAPK14, ATM and CK2ALPHA was identified as top 5 kinases in CC. miRNAs analysis showed that Hsa-miR-215-5p hsa-miR-193b-3p, hsa-miR-192-5p and hsa-miR-16-5p could target the largest number of CC genes. Taken together, CC-related genes, especially the hub genes, TFs, and metabolites might be used as novel biomarkers for CC, as well as for diagnosis and guiding therapeutic strategies for CC.

Lactoferrin: A Nutraceutical with Activity against Colorectal Cancer

Homeostasis in the human body results from the tight regulation of several events, since too little inflammation disrupts the process of tissue repair and remodeling, whereas too much exerts a collateral effect by causing tissue damage with life-threatening consequences. In some clinical conditions, such as inflammatory bowel disease (IBD), inflammation functions as a double-edged sword by either enabling or inhibiting cancer development and progression. Generally, cancer develops through evasion mechanisms that regulate cell growth, causing a high rate of uncontrolled proliferation, and mechanisms for evading cell death, such as apoptosis. Moreover, chronic inflammation is a factor that contributes to colorectal cancer (CRC), as observed in individuals with IBD; all these conditions favor an increased rate of angiogenesis and eventual metastasis. Lactoferrin (Lf) is a mammalian iron-binding multifunctional glycoprotein regarded as a natural compound that up- and downregulates both humoral and cellular components of immunity involved in regulating the inflammatory response and maintaining gut homeostasis. Human and bovine Lf share high sequence homology and have very similar antimicrobial, anti-inflammatory, and immunomodulatory activities. Bovine Lf from milk is considered a safe molecule and is commercially available in large quantities. This review mainly focuses on the regulatory effects of orally administered bovine Lf on the inflammatory response associated with CRC; this approach indicates that CRC is one of the most frequently diagnosed cancers and affects the intestinal tract with high clinical and epidemiologic relevance. Thus, this review may provide foundations for the potential use of bovine Lf alone or as a natural adjunct agent to increase the effectiveness and reduce the side effects of anticancer chemotherapy.

Protective effect of methanol extract of latex of Calotropis procera in an experimental model of colorectal cancer

ETHNOPHARMACOLOGICAL RELEVANCE

The plant, Calotropis procera, has been used for treating various gastrointestinal disorders and cancer. Some of these medicinal properties have been attributed to the latex produced by the plant.

AIM OF THE STUDY

To evaluate the efficacy of methanol extract of air-dried latex (MeDL) of C. procera in the rat model of colorectal cancer (CRC).

MATERIALS AND METHODS

CRC was induced in the rats by 1,2-dimethylhydrazine (DMH) and the effect of MeDL was evaluated at two doses (50 and 150 mg/kg). MeDL and reference drug aspirin (60 mg/kg) were administered orally starting from 1 h before injecting DMH till 8 weeks after the second dose of DMH. The study also included experimental and normal control groups. Microscopic analysis was carried out to determine the count for aberrant crypt foci (ACF) and histology score whereas enzyme-linked immunosorbent assay and immunohistochemical analyses were performed for markers of carcinogenesis and angiogenesis. Other parameters that were evaluated include deoxyribonucleic acid (DNA) fragmentation, laddering, Bcl₂ and Bax immunoreactivity, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) positivity.

RESULTS

Subcutaneous injection of DMH induced pre-neoplastic changes in the colon of rats with the appearance of ACF with multiple crypts (1-3, 4-6 or >6). In the experimental control group, total ACF count was 3.49 ± 0.23/cm of the colon length and the median histology score was 2.0 for architectural abnormalities, 2.0 for dilatation of crypts and 1.5 for hyperplasia/dysplasia against 1.0 for all the characteristics in normal rats. Oral administration of MeDL similar to aspirin, led to a reduction in ACF count and histology score of CRC concomitant with a decrease in the levels of markers of carcinogenesis - β-catenin and proliferating cell nuclear antigen (PCNA); markers of angiogenesis - matrix metallopeptidase-9 (MMP-9) and vascular endothelial growth factor (VEGF), and an increase in apoptotic DNA fragmentation.

CONCLUSION

MeDL confers protection in the rat model of CRC and the study suggests its therapeutic potential in this condition.

CDKN2B antisense RNA 1 suppresses tumor growth in human colorectal cancer by targeting MAPK inactivator dual-specificity phosphatase 1

Aberrant expression of long noncoding RNA cyclin-dependent kinase inhibitor 2B antisense RNA 1 (CDKN2B-AS1) has been detected in human colorectal cancer (CRC). This study aimed to investigate the role of CDKN2B-AS1 and the underlying mechanism in human CRC. Gain- and loss-of-function assays were performed to explore the role of CDKN2B-AS1 in the malignant behavior of HCT116 and SW480 CRC cells in vitro and in vivo. RNA pull-down assay was conducted to identify the target of CDKN2B-AS1 in CRC cells. The physical and functional interactions between CDKN2B-AS1 and the target were examined. CDKN2B-AS1 inhibited CRC cell proliferation and migration while promoting apoptosis in vitro via activation of mitogen-activated protein kinase kinases (MEK)/extracellular signal-regulated kinase (ERK)/p38 signaling. CDKN2B-AS1 bound to mitogen-activated protein kinase (MAPK) inactivator dual-specificity phosphatase 1 (DUSP1) in CRC cells. In contrast to CDKN2B-AS1, DUSP1 promoted CRC cell proliferation, suppressed apoptosis and inactivated MEK/ERK/p38 signaling in CRC cells. Furthermore, CDKN2B-AS1 overexpression attenuated DUSP1 expression in normal colonic myofibroblasts and CRC cells. Overexpression of DUSP1 effectively countered the activation of MEK/ERK/p38 signaling induced by CDKN2B-AS1 overexpression or further blocked MEK/ERK/p38 signaling suppressed by CDKN2B-AS1 silencing. In the mouse xenograft model, CDKN2B-AS1 suppressed CRC growth, whereas DUSP1 promoted CRC growth. CDKN2B-AS1 induced cell apoptosis while suppressing EMT (epithelial-mesenchymal transition), whereas DUSP1 suppressed cell apoptosis while inducing EMT in CRC, as evidenced by the alterations in the protein levels of apoptosis and EMT markers in tumor tissue samples. CDKN2B-AS1 regulates CRC cell growth and survival by targeting MAPK inactivator DUSP1.

Melatonin increases 5-flurouracil-mediated apoptosis of colorectal cancer cells through enhancing oxidative stress and downregulating survivin and XIAP

Introduction: Colorectal cancer (CRC) is one of the most lethal human malignancies with a global alarming rate of incidence. The development of resistance against common chemotherapeutics such as 5-fluorouracil (5-FU) remains a big burden for CRC therapy. Therefore, we investigated the effects of melatonin on the increasing 5-FU- mediated apoptosis and its underlying mechanism in SW-480 CRC cell line.

Methods: The effects of melatonin and 5- FU, alone or in combination, on cell proliferation were evaluated using an MTT assay. Further, Annexin-V Flow cytometry was used for determining the effects of melatonin and 5-FU on the apoptosis of SW-480 cell lines. The expression levels of Bax, Bcl-2, pro-caspase-3/activated caspase 3, X-linked inhibitor of apoptosis proteins (XIAP), and survivin were measured after 48 hours incubation with drugs. Cellular levels of reactive oxygen species (ROS), catalase, superoxide dismutase and glutathione peroxidase were also evaluated.

Results: Melatonin and 5-FU significantly decreased the cell proliferation of SW-480 cells. Combination of 5-FU with melatonin significantly decreased the IC50 value of 5-FU from 100 μM to 50 μM. Moreover, combination therapy increased intracellular levels of ROS and suppressed antioxidant enzymatic activities (P < 0.05). Treatment with either melatonin or 5-FU resulted in the induction of apoptosis in comparison to control (P > 0.05). XIAP and survivin expression levels potently decreased after combination treatment with melatonin and 5-FU (P  < 0.05).

Conclusion: We demonstrated that melatonin exerts a reversing effect on the resistance to apoptosis by targeting oxidative stress, XIAP and survivin in CRC cells. Therefore, more studies need for better understanding of underlying mechanisms for beneficial effects of combination of melatonin and 5-FU.

Synergistic Anti-proliferative Effects of Lenalidomide and Dexamethasone on the HT-29 Cell Line Through Apoptotic Genes

Background: Colorectal cancer (CRC) is the third most common cancer among men and the second most common type of cancer among women worldwide. The resistance of tumor cells to apoptosis is caused by changes in the expression of anti-apoptotic or pro-apoptotic proteins. Histone deacetylase inhibitors (HDACi) are known to cause changes in gene expression. Objectives: The present study aimed at investigating the anti-proliferative effects of lenalidomide (LEN) as HDACi and dexamethasone (DEX) on the human colon cancer HT-29 cell line. Methods: The HT-29 cell line was treated with various concentrations of LEN and DEX individually and in combination for 24, 48, and 72 hours. Cytotoxicity was evaluated by MTT assay. The half-maximal inhibitory concentration (IC50) was measured, and quantitative real-time polymerase chain reaction (qRT-PCR) was also performed to examine the expression of Bcl2, Bax, Fas, and FasL genes. Results: The combination of LEN (1000 µM) with DEX (100 µM) showed potent synergistic anti-proliferative activities in a time- and dose-dependent manner. The combination of these drugs induced cell death by affecting the extrinsic and intrinsic apoptotic gene expression profiles. Conclusions: The combination of LEN with DEX can be proposed as a new therapeutic approach for CRC.

Suppressive effects of dental pulp stem cells and its conditioned medium on development and migration of colorectal cancer cells through MAPKinase pathways

OBJECTIVES

Mesenchymal stem cells (MSCs) extensively interact with cancer cells and other stromal cells in the tumor microenvironment. However, the role of MSCs in colorectal cancer (CRC) development and metastasis is controversial. Strong evidence demonstrated that conditioned medium (CM) obtained from MSCs regulates main cellular functions such as proliferation, differentiation, migration, and communication due to its cell secretomes. This study was designed to determine the inhibitory effect of dental pulp stem cells (DPSC) and its extracted conditioned medium (DPSC-CM) in CRC progression.

MATERIALS AND METHODS

The inhibitory effects of DPSC-CM on growth, apoptosis, and migration of CRC cells were evaluated by resazurin, flow cytometry of propidium iodide (PI) stained cells, and wound closure assay, respectively. Western blotting detected the expression of MAPKinase and apoptotic proteins. Also, the homing ability of DPSCs and the invasion ability of CRC cells under indirect co-culture were assayed by the Boyden chamber assay.

RESULTS

DPSC-CM reduced the viability and induced the apoptosis of CRC cells significantly. Western blot analysis confirmed the increase in cytochrome C, phospho-JNK/SAPK to JNK/SAPK ratio, cleaved-caspase 8 and 3 in treated CRC cells with DPSC-CM, and decrease in phospho-ERK (P44/42 MAPK) to ERK (P44/42 MAPK) ratio, which are involved in induction of apoptosis and growth inhibition of cancer cells with minimal change in normal cells. Also, DPSCs could migrate (homing ability) to Caco₂ and SW48 cells significantly.

CONCLUSION

To sum up, DPSC-CM had significant apoptotic and growth inhibitory effects on the CRC cells through the MAPKinase and apoptosis signaling pathways.

S-Adenosylmethionine Increases the Sensitivity of Human Colorectal Cancer Cells to 5-Fluorouracil by Inhibiting P-Glycoprotein Expression and NF-κB Activation

Colorectal cancer (CRC) is the second deadliest cancer worldwide despite significant advances in both diagnosis and therapy. The high incidence of CRC and its poor prognosis, partially attributed to multi-drug resistance and antiapoptotic activity of cancer cells, arouse strong interest in the identification and development of new treatments. S-Adenosylmethionine (AdoMet), a natural compound and a nutritional supplement, is well known for its antiproliferative and proapoptotic effects as well as for its potential in overcoming drug resistance in many kinds of human tumors. Here, we report that AdoMet enhanced the antitumor activity of 5-Fluorouracil (5-FU) in HCT 116^p53+/+ and in LoVo CRC cells through the inhibition of autophagy, induced by 5-FU as a cell defense mechanism to escape the drug cytotoxicity. Multiple drug resistance is mainly due to the overexpression of drug efflux pumps, such as P-glycoprotein (P-gp). We demonstrate here that AdoMet was able to revert the 5-FU-induced upregulation of P-gp expression and to decrease levels of acetylated NF-κB, the activated form of NF-κB, the major antiapoptotic factor involved in P-gp-related chemoresistance. Overall, our data show that AdoMet, was able to overcome 5-FU chemoresistance in CRC cells by targeting multiple pathways such as autophagy, P-gp expression, and NF-κB signaling activation and provided important implications for the development of new adjuvant therapies to improve CRC treatment and patient outcomes.

DPP3/CDK1 contributes to the progression of colorectal cancer through regulating cell proliferation, cell apoptosis, and cell migration

At present, colorectal cancer (CRC) has become a serious threat to human health in the world. Dipeptidyl peptidase 3 (DPP3) is a zinc-dependent hydrolase that may be involved in several physiological processes. However, whether DPP3 affects the development and progression of CRC remains a mystery. This study is the first to demonstrate the role of DPP3 in CRC. Firstly, the results of immunohistochemistry analysis showed the upregulation of DPP3 in CRC tissues compared with normal tissues, which is statistically analyzed to be positively correlated with lymphatic metastasis, pathological stage, positive number of lymph nodes. Moreover, the high expression of DPP3 predicts poor prognosis in CRC patients. In addition, the results of cell dysfunction experiments clarified that the downregulation of DPP3 significantly inhibited cell proliferation, colony formation, cell migration, and promoted apoptosis in vitro. DPP3 depletion could induce cell apoptosis by upregulating the expression of BID, BIM, Caspase3, Caspase8, HSP60, p21, p27, p53, and SMAC. In addition, downregulation of DPP3 can reduce tumorigenicity of CRC cells in vivo. Furthermore, CDK1 is determined to be a downstream target of DPP3-mediated regulation of CRC by RNA-seq, qPCR, and WB. The interaction between DPP3 and CDK1 shows mutual regulation. Specifically, downregulation of DPP3 can accentuate the effects of CDK1 knockdown on the function of CRC cells. Overexpression of CDK1 alleviates the inhibitory effects of DPP3 knockdown in CRC cells. In summary, DPP3 has oncogene-like functions in the development and progression of CRC by targeting CDK1, which may be an effective molecular target for the prognosis and treatment of CRC.

Role of Stress-Survival Pathways and Transcriptomic Alterations in Progression of Colorectal Cancer: A Health Disparities Perspective

Every year, more than a million individuals are diagnosed with colorectal cancer (CRC) across the world. Certain lifestyle and genetic factors are known to drive the high incidence and mortality rates in some groups of individuals. The presence of enormous amounts of reactive oxygen species is implicated for the on-set and carcinogenesis, and oxidant scavengers are thought to be important in CRC therapy. In this review, we focus on the ethnicity-based CRC disparities in the U.S., the negative effects of oxidative stress and apoptosis, and gene regulation in CRC carcinogenesis. We also highlight the use of antioxidants for CRC treatment, along with screening for certain regulatory genetic elements and oxidative stress indicators as potential biomarkers to determine the CRC risk and progression.

El-kherbetawy M, El-mistekawy A, Mohammad HMF, Elbahaie AM, Hashish AA, Alomar SY, Aloyouni SY, El-dosoky M, Morsy KM, Zaitone SA. Antitumor Activity of Nitazoxanide against Colon Cancers: Molecular Docking and Experimental Studies Based on Wnt/β-Catenin Signaling Inhibition

In colon cancer, wingless (Wnt)/β-catenin signaling is frequently upregulated; however, the creation of a molecular therapeutic agent targeting this pathway is still under investigation. This research aimed to study how nitazoxanide can affect Wnt/β-catenin signaling in colon cancer cells (HCT-116) and a mouse colon cancer model. Our study included 2 experiments; the first was to test the cytotoxic activity of nitazoxanide in an in vitro study on a colon cancer cell line (HCT-116) versus normal colon cells (FHC) and to highlight the proapoptotic effect by MTT assay, flow cytometry and real-time polymerase chain reaction (RT-PCR). The second experiment tested the in vivo cytotoxic effect of nitazoxanide against 1,2-dimethylhydrazine (DMH) prompted cancer in mice. Mice were grouped as saline, DMH control and DMH + nitazoxanide [100 or 200 mg per kg]. Colon levels of Wnt and β-catenin proteins were assessed by Western blotting while proliferation was measured via immunostaining for proliferating cell nuclear antigen (PCNA). Treating HCT-116 cells with nitazoxanide (inhibitory concentration 50 (IC50) = 11.07 µM) revealed that it has a more cytotoxic effect when compared to 5-flurouracil (IC50 = 11.36 µM). Moreover, it showed relatively high IC50 value (non-cytotoxic) against the normal colon cells. Nitazoxanide induced apoptosis by 15.86-fold compared to control and arrested the cell cycle. Furthermore, nitazoxanide upregulated proapoptotic proteins (P53 and BAX) and caspases but downregulated BCL-2. Nitazoxanide downregulated Wnt/β-catenin/glycogen synthase kinase-3β (GSK-3β) signaling and PCNA staining in the current mouse model. Hence, our findings highlighted the cytotoxic effect of nitazoxanide and pointed out the effect on Wnt/β-catenin/GSK-3β signaling.

K. H, Basavaraju P, Pasumarthi D, S. D. A, Soujanya P, Arnold Emeson I, Bodiga V, Pawar SC. Inhibition of Inducible Nitric Oxide Synthase (iNOS) by Andrographolide and In Vitro Evaluation of Its Antiproliferative and Proapoptotic Effects on Cervical Cancer

This work is aimed at investigating the expression levels of inducible nitric oxide synthase (iNOS) in cervical cancer and identifying a potential iNOS inhibitor. The data mining studies performed advocated iNOS to be a promising biomarker for cancer prognosis, as it is highly overexpressed in several malignant cancers. The elevated iNOS was found to be associated with poor survival and increased tumor aggressiveness in cervical cancer. Immunohistochemical and RT-PCR investigations of iNOS showed significant upregulation of endogenous iNOS expression in the cervical tumor samples, thus making iNOS a potent target for decreasing tumor inflammation and aggressiveness. Andrographolide, a plant-derived diterpenoid lactone, is widely reported to be effective against infections and inflammation, causing no adverse side effects on humans. In the current study, we investigated the effect of andrographolide on the prognostic value of iNOS expression in cervical cancer, which has not been reported previously. The binding efficacy of andrographolide was analyzed by performing molecular docking and molecular dynamic simulations. Multiple parameters were used to analyze the simulation trajectory, like root mean square deviation (RMSD), torsional degree of freedom, protein-root mean square fluctuations (P-RMSF), ligand RMSF, total number of intramolecular hydrogen bonds, secondary structure elements (SSE) of the protein, and protein complex with the time-dependent functions of MDS. Ligand-protein interactions revealed binding efficacy of andrographolide with tryptophan amino acid of iNOS protein. Cancer cell proliferation, cell migration, cell cycle analysis, and apoptosis-mediated cell death were assessed in vitro, post iNOS inhibition induced by andrographolide treatment (demonstrated by Western blot). Results. Andrographolide exhibited cytotoxicity by inhibiting the in vitro proliferation of cervical cancer cells and also abrogated the cancer cell migration. A significant increase in apoptosis was observed with increasing andrographolide concentration, and it also induced cell cycle arrest at G1-S phase transition. Our results substantiate that andrographolide significantly inhibits iNOS expression and exhibits antiproliferative and proapoptotic effects on cervical cancer cells.

Identification and development of a novel invasion-related gene signature for prognosis prediction in colon adenocarcinoma

The overall survival of metastatic colon adenocarcinoma (COAD) remains poor, so it is important to explore the mechanisms of metastasis and invasion. This study aimed to identify invasion-related genetic markers for prognosis prediction in patients with COAD. Three molecular subtypes (C1, C2, and C3) were obtained based on 97 metastasis-related genes in 365 COAD samples from The Cancer Genome Atlas (TCGA). A total of 983 differentially expressed genes (DEGs) were identified among the different subtypes by using the limma package. A 6-gene signature (ITLN1, HOXD9, TSPAN11, GPRC5B, TIMP1, and CXCL13) was constructed via Lasso-Cox analysis. The signature showed strong robustness and could be used in the training, testing, and external validation (GSE17537) cohorts with stable predictive efficiency. Compared with other published signatures, our model showed better performance in predicting outcomes. Pan-cancer expression analysis results showed that ITLN1, TSPAN11, CXCL13, and GPRC5B were downregulated and TIMP1 was upregulated in most tumor samples, including COAD, which was consistent with the results of the TCGA and GEO cohorts. Western blot analysis and immunohistochemistry were performed to validate protein expression. Tumor immune infiltration analysis results showed that TSPAN11, GPRC5B, TIMP1, and CXCL13 protein levels were significantly positively correlated with CD4+ T cells, macrophages, neutrophils, and dendritic cells. Further, the TIMP1 and CXCL13 proteins were significantly related to the tumor immune infiltration of CD8+ T cells. We recommend using our signature as a molecular prognostic classifier to assess the prognostic risk of patients with COAD.

Gutting it Out: Developing Effective Immunotherapies for Patients With Colorectal Cancer

Risk factors for colorectal cancer (CRC) include proinflammatory diets, sedentary habits, and obesity, in addition to genetic syndromes that predispose individuals to this disease. Current treatment relies on surgical excision and cytotoxic chemotherapies. There has been a renewed interest in immunotherapy as a treatment option for CRC given the success in melanoma and microsatellite instable (MSI) CRC. Immunotherapy with checkpoint inhibitors only plays a role in the 4%-6% of patients with MSIhigh tumors and even within this subpopulation, response rates can vary from 30% to 50%. Most patients with CRC do not respond to this modality of treatment, even though colorectal tumors are frequently infiltrated with T cells. Tumor cells limit apoptosis and survive following intensive chemotherapy leading to drug resistance and induction of autophagy. Pharmacological or molecular inhibition of autophagy improves the efficacy of cytotoxic chemotherapy in murine models. The microbiome clearly plays an etiologic role, in some or most colon tumors, realized by elegant findings in murine models and now investigated in human clinical trials. Recent results have suggested that cancer vaccines may be beneficial, perhaps best as preventive strategies. The search for therapies that can be combined with current approaches to increase their efficacy, and new knowledge of the biology of CRC are pivotal to improve the care of patients suffering from this disease. Here, we review the basic immunobiology of CRC, current "state-of-the-art" immunotherapies and define those areas with greatest therapeutic promise for the future.

Noxa upregulation and 5-gene apoptotic biomarker panel in colorectal cancer

BACKGROUND

NOXA and MCL1 are involved in the intrinsic pathway of apoptosis, where Noxa selectively binds to MCL1 and prevents it from inhibiting apoptosis. Both factors are considered as potential tumour biomarkers, while MCL1 has attracted interest as target in cancer. The purpose of this study was to investigate the expression of NOXA and MCL1 in 160 CRC tumour samples, to investigate their significance, also in combination with IAPs, DR5 expression and KRAS gene mutations in CRC.

MATERIALS AND METHODS

Fresh frozen colorectal tissue was obtained from patients undergoing surgery for CRC. Real-time quantitative PCR was performed for the determination of mRNA expression levels. Protein expression was determined immunohistochemically. Differences in the mRNA expression profile were evaluated with the nonparametric Wilcoxon signed ranks test. Statistical analysis was performed with the use of Mann-Whitney U test and receiver-operating characteristic (ROC) curve.

RESULTS

NOXA was found to be overexpressed in CRC tumours (P < .0001), even from early stage. Moreover, NOXA/MCL1 mRNA expression was significantly elevated in tumour samples compared to normal pairs (P < .0001). ROC curve analysis showed that both NOXA expression and its combination with Mcl1 expression have fair discriminatory value between CRC and normal colorectal tissue. Combinatorial ROC analysis revealed the most significant discriminatory value of NOXA, MCL1 with cIAP1 and cIAP2 (AUC = 0.834, P < .0001) as a 5-gene panel of markers.

CONCLUSION

Noxa, Mcl1, DR5, cIAP1 and cIAP2 mRNA expressions are significantly deregulated in CRC and could provide a panel of markers with significant discriminatory value between CRC and normal colorectal tissue.

S-adenosylmethionine induces apoptosis and cycle arrest of gallbladder carcinoma cells by suppression of JAK2/STAT3 pathways

S-adenosylmethionine (SAM) is a naturally occurring physiologic molecule found ubiquitously in all mammalian cells and an essential compound in many metabolic pathways. It has been reported to possess many pharmacological properties including cancer-preventive and anticancer effects. However, the precise molecular mechanism involved in its anticancer effect is not yet clear. The present study is conducted to investigate the anticancer activity and the underlying mechanisms of SAM on human gallbladder cancer cells (GBC-SD and SGC-996) in vitro and in vivo. Cells were dealt with SAM and subjected to cell viability, colony formation, Hoechst staining, apoptosis, cycle arrest, western blot, and xenograft tumorigenicity assay. Experimental results showed that SAM could significantly inhibit the growth and proliferation and induce the apoptosis as well as cell cycle arrest in G0/G1 phase of GBC-SD and SGC-996 cells in a dose-dependent manner in vitro. The expression levels of p-JAK2, p-STAT3, Mcl-1, and Bcl-XL were significantly downregulated. In addition, inhibition of the JAK2/STAT3 pathway significantly enhanced the anti-apoptotic effect of SAM, suggesting the key roles of JAK2/STAT3 in the process. More importantly, our in vivo studies demonstrated that administration of SAM could significantly decrease the tumor weight and volume and immunohistochemistry analysis proved the downregulation of p-JAK2 and p-STAT3 in tumor tissues following SAM treatment, consistent with our in vitro results. In summary, our findings indicated that SAM can inhibit cell proliferation and induce apoptosis as well as cycle arrest of GBC cells by suppression of JAK2/STAT3 pathways and the dramatic effects of SAM hinting that SAM might be a useful therapeutic option for patients suffering from gallbladder cancer.

A small natural molecule CADPE kills residual colorectal cancer cells by inhibiting key transcription factors and translation initiation factors

Residual disease is the major cause for colorectal cancer (CRC) relapse. Herein, we explore whether and how a natural molecule CADPE killed heterogenic populations in a panel of CRC cell lines with KRAS/BRAF mutations that are natively resistant to EGFR- or VEGFR-targeted therapy, without sparing persistent cells, a reservoir of the disease relapse. Results showed that CADPE killed the tumor bulk and residual cells in the panel of CRC cell lines, rapidly inactivated c-Myc, STAT3, and NF-κB, and then decreased the protein levels of key signaling molecules for CRC, such as β-catenin, Notch1, and the nodes of mTOR pathways; eukaryotic translation initiation factors (eIF4F); anti-apoptotic proteins (Bcl-xl, Mcl-1, and survivin); and stemness-supporting molecules (CD133, Bim-1, and VEGF). In terms of mechanism of action, concurrent downregulation of Mcl-1, Bcl-xl, and survivin was necessary for CADPE to kill CRC bulk cells, while additional depletion of CD133 and VEGF proteins was required for killing the residual CRC cells. Moreover, the disabled c-Myc, STAT3, NF-κB, and eIF4F were associated with the broadly decreased levels of anti-apoptosis proteins and pro-stemness proteins. Consistently, CADPE suppressed CRC tumor growth associated with robust apoptosis and depleted levels of c-Myc, STAT3, NF-κB, eIF4F, anti-apoptotic proteins, and pro-stemness proteins. Our findings showed the promise of CADPE for treating CRC and suggested a rational polytherapy that disables c-Myc, STAT3, NF-κB, and eIF4F for killing CRC residual disease.

Forkhead box P3 promotes breast cancer cell apoptosis by regulating programmed cell death 4 expression

Forkhead box P3 (FOXP3), an X-linked tumor suppressor gene, plays an important role in breast cancer. However, the biological functions of FOXP3 in breast cancer apoptosis remain unclear. To investigate the underlying genes and networks regulated by FOXP3 in breast cancer, RNA sequencing was performed to compare FOXP3-overexpressing MDA-MB-231 cells and control MDA-MB-231 cells. Differentially expressed genes were identified, and functional enrichment analysis comparing the two groups was performed. The differentially expressed genes were mainly enriched in phagosomes, oxytocin, serotonergic synapses and the phospholipase D signaling pathway. Furthermore, gene set enrichment analysis revealed the enrichment of a gene signature associated with apoptosis in FOXP3-overexpressing MDA-MB-231 cells compared with wild-type cells. Further analysis showed that programmed cell death 4 (PDCD4), a key molecule involved in apoptosis, was overexpressed in FOXP3-MDA-MB-231 cells. Reverse transcription-quantitative PCR and western blotting showed that FOXP3 upregulated the expression of PDCD4 in breast cancer cells. Clinical sample analysis using a public database showed that the expression level of PDCD4 was associated with breast cancer clinical stages. Overall, the present study suggested that FOXP3 can promote the apoptosis of breast cancer cells by upregulating the expression of PDCD4, thus exerting a tumor suppressive function.

The Effects of Doxorubicin, Ethanol Extract and Flavonoid-rich Fraction of Euphorbia Splendida Mobayen on the PARP Level, and APC Gene Expression in HT-29 Human Colon Cancer Cell Line

Background: Natural products derived from various sources are being used to develop chemotherapeutic drugs. Euphorbiaceae is widely used to treat different types of cancers. Colorectal cancer (CRC) is the second and third cause of cancer in women and men, respectively. CRC is strongly associated with the deregulation of the Adenomatous polyposis coli (APC) gene and Poly [ADP-ribose] polymerase (PPAR) protein. Objectives: The current study aimed to examine the effect of doxorubicin, ethanol extract, and the flavonoid-rich fraction of Euphorbia Splendida Mobayen on colon cancer HT-29 cell line death, APC gene expression, and PPAR concentration. Methods: Following treatment of cells by Euphorbia ethanol extract, Euphorbia flavonoid-rich fraction, and doxorubicin, cell viability assay was used to investigate the viability status of the HT-29 cell line. Total RNA was isolated from the cell line and converted into cDNA. The expression level of the APC gene was determined by quantitative real-time PCR. Poly (ADP-ribose) polymerase (PPAR) protein was detected by the ELIZA method. Results: We found that Euphorbia ethanol extract, Euphorbia flavonoid-rich fraction, and doxorubicin can stimulate dose-dependent cell death in the HT-29 cell line, increase ACP gene expression (P = 0.001, P = 0.041, P = 0.019), and decrease PARP level (P = 0.001, P = 0.001, P = 0.001, respectively). Conclusions: The findings indicated that doxorubicin, ethanol extract, and the flavonoid-rich fraction of Euphorbia Splendida Mobayen had cytotoxic effects on human colon cancer HT-29 cell line by possibly stimulating apoptosis.

MicroRNA: Another Pharmacological Avenue for Colorectal Cancer?

MicroRNAs (miR) are single-stranded RNA of 21-23 nucleotides in length that repress mRNA translation and induces mRNA degradation. miR acts as an endogenous factor of gene expression and plays a crucial part in cancer biology such as cell development, proliferation, differentiation, and apoptosis. Numerous research has indicated that dysregulation of miR associates with colorectal carcinogenesis. In this review article, we firstly introduce the background of miR and colorectal cancer, and the mechanisms of miR in colorectal cancer, such as the proliferation, apoptosis, and progression. Then, we summarize the theranostic value of miR in colorectal cancer. Eventually, we discuss the potential directions and perspectives of miR. This article serves as a guide for further studies and implicate miR as a potent theranostic target for colorectal cancer.

A refined cocktailing of pro-apoptotic nanoparticles boosts anti-tumor activity

A functional 29 amino acid-segment of the helix α5 from the human BAX protein has been engineered for production in recombinant bacteria as self-assembling, GFP-containing fluorescent nanoparticles, which are targeted to the tumoral marker CXCR4. These nanoparticles, of around 34 nm in diameter, show a moderate tumor biodistribution and limited antitumoral effect when systemically administered to mouse models of human CXCR4⁺ colorectal cancer (at 300 μg dose). However, if such BAX nanoparticles are co-administered in cocktail with equivalent nanoparticulate versions of BAK and PUMA proteins at the same total protein dose (300 μg), protein biodistribution and stability in tumor is largely improved, as determined by fluorescence profiles. This fact leads to a potent and faster destruction of tumor tissues when compared to individual pro-apoptotic factors. The analysis and interpretation of the boosted effect, from both the structural and functional sides, offers clues for the design of more efficient nanomedicines and theragnostic agents in oncology based on precise cocktails of human proteins. STATEMENT OF SIGNIFICANCE: Several human pro-apoptotic peptides (namely BAK, BAX and PUMA) have been engineered as self-assembling protein nanoparticles targeted to the tumoral marker CXCR4. The systemic administration of the same final amounts of those materials as single drugs, or as combinations of two or three of them, shows disparate intensities of antitumoral effects in a mouse model of human colorectal cancer, which are boosted in the triple combination on a non-additive basis. The superiority of the combined administration of pro-apoptotic agents, acting at different levels of the apoptotic cascade, opens a plethora of possibilities for the development of effective and selective cancer therapies based on the precise cocktailing of pro-apoptotic nanoparticulate agents.

Anti-cancer properties of Escherichia coli Nissle 1917 against HT-29 colon cancer cells through regulation of Bax/Bcl-xL and AKT/PTEN signaling pathways

Objectives

Chemotherapies used to treat colon cancer might often fail due to the emergence of chemoresistance and side effects. Escherichia coli Nissle 1917 (EcN) is a beneficial probiotic, whose molecular mechanisms in the prevention of colon cancer are yet to be fully understood. The present study assessed the anti-cancer effects of EcN treatments in human colorectal cancer, HT-29 cell line, with the analysis of related mechanisms.

Materials and Methods

The co-culture conditioned-media (CM) of EcN with adenocarcinoma HT-29 cells and heat-inactivated bacteria (HIB) were applied for the treatment of the HT-29 cells. To study the inhibition potential of CM and HIB on cancer cells, various cellular/molecular analyses were implemented, including DAPI-staining and DNA ladder assays, flow cytometry and Real-time quantitative PCR (qPCR), as well as Western blotting analyses.

Results

Our results indicated that EcN could elicit apoptotic impacts on the colon cancer HT-29 cells by up-regulating PTEN and Bax and down-regulating AKT1 and Bcl-xL genes.

Conclusion

Based on our findings, EcN is proposed as a useful supplemental probiotic treatment against colon cancer.

Probiotic Lactobacillus salivarius Ren prevent dimethylhydrazine-induced colorectal cancer through protein kinase B inhibition

Probiotics are known to be a potential agent for colorectal cancer (CRC) inhibition, but the precise mechanisms by which probiotic exert anti-tumorigenic effects remain to be explored. Lactobacillus salivarius (LS) Ren was isolated from centenarians living in Bama of China, which showed an anticancer potent in animal model of oral cancer. Here, we investigated the effect of LS on colorectal carcinogenesis and its putative mechanism. Oral administration of LS effectively suppressed the formation of dimethylhydrazine (DMH)-induced CRC in both initial and post-initial stages. Significant antiproliferation and proapoptotic effects were observed with inhibition of tumor formation by dietary intake of LS. Besides, LS metabolites inhibited growth, arrested cell cycle, and induced apoptosis of HT-29 cells. Furthermore, upon the treatment of LS, protein kinase B (AKT) phosphorylation and the downstream proteins of cyclinD1 and cyclooxygenase-2 (COX-2) were significantly downregulated in both in vivo and in vitro tests. These results showed that LS inhibited the colorectal carcinogenesis through suppressing AKT signaling pathway, resulting in suppressing cell proliferation and inducing cell apoptosis. Our findings suggest that this probiotic may act as a prophylactic agent for CRC prevention. Key points • LS effectively prevented rat colorectal carcinogenesis induced by DMH. • LS modulated the proliferation and apoptosis in both in vivo and in vitro. • LS inhibited AKT phosphorylation and expressions of downstream cyclinD1 and COX-2.

β-Elemene Enhances the Chemotherapeutic Effect of 5-Fluorouracil in Triple-Negative Breast Cancer via PI3K/AKT, RAF-MEK-ErK, and NF-κB Signaling Pathways

Background

The most common chemotherapeutic drug for triple-negative breast cancer (TNBC) treatment is 5-fluorouracil (5-FU), but its therapeutic index is low due to its toxicity. β-Elemene (ELE) possesses antitumor activity against different cancers, but it has never been used in combination with 5-FU to improve its chemotherapeutic effect against TNBC.

Materials and Methods

We treated MDA-MB-231 and BT549 cells of TNBC with ELE alone, 5-FU alone, or their combination to investigate their treatment effects on cell viability, proliferation, migration, invasion, and colony formation. We verified the molecular mechanisms of our results through confocal immunofluorescence, immunohistochemistry, and Western blot analysis in vitro and in vivo.

Results

Our result revealed that ELE enhanced the 5-FU effect against cell viability, proliferation, migration, invasion, and colony formation through different mechanisms in MDA-MB-231 and BT549 cell lines. In molecular mechanisms, ELE and 5-FU in combination enhances apoptosis in both cell lines through Bl-2 family protein and caspase cascade modulation, thereby inhibiting NF-kB pathway through IKKβ, IKKα, and p65 downregulation in the cytoplasm and p50 and p65 downregulation in the nucleus. ELE and 5-FU in combination regulated the PI3K/AKT pathway through p-AKT, P-85, p110r, p-PDK1, and p110a protein and RAF-MEK-ERK pathway inhibition through the p-c-raf and p-ERK downregulation. The PI3K inhibitor LY294002 or RAF-MEK-ERK inhibitor U0126 in combination with ELE and 5-FU decreased cell viability in both cell lines significantly, thereby showing the involvement of these pathways in cell apoptosis. In mouse xenograft model, ELE and 5-FU in combination inhibited the tumor growth and modulated its molecular markers.

Conclusion

The conclusion obtained, considering that the results suggest that the combination may be important specifically in the treatment of TNBC.

Synthetic antiprotozoal thiazolide drug induced apoptosis in colorectal cancer cells: implications of IL-6/JAK2/STAT3 and p53/caspases-dependent signaling pathways based on molecular docking and in vitro study

Colorectal cancer (CRC) is a global pressing healthcare priority. Dysregulation of the IL6/JAK2/STAT3 and p53/caspase downstreaming pathways are significantly involved in the progression of CRC, and mainly affecting apoptosis. Discovery of new anti-cancer agents is laborious, time consuming, and costly with obvious socioeconomic burden. In the present study, we are proposing new molecular insights on the anti-proliferative and apoptotic therapeutic effects of nitazoxanide (NTZ) on CRC. NTZ is FDA-approved thiazolide antiparasitic agent, which has excellent safety and pharmacokinetic profiles. The molecular docking study revealed that NTZ has better binding affinity and docking score against JAK2 and BCL2 proteins compared to 5-Fluorouracil, which is the standard drug for treatment of CRC. The current in vitro work on a human HCT116 cell line displayed that NTZ had lower IC₅₀ value (11.20 µM) than 5-flurouracil (23.78 µM), and NTZ induced a statistically significant down-regulation of IL6/JAK2/STAT3. NTZ also modulated significantly the p53/caspases-dependent signaling pathways, leading to enhancement of apoptosis and an increase of DNA fragmentation. Moreover, NTZ regulated the Bcl-2 gene family and promoted the loss of mitochondrial function which was depicted by release of cytochrome c (Cyt c), and caspase activation in apoptotic HCT116 cells. Additionally, NTZ was able to reduce the expression of VEGF in CRC cell line, which needs future thorough molecular investigations. In conclusion, our findings provided a novel evidence that NTZ could be a dual potential IL6/JAK2/STAT3 signaling inhibitor and p53/caspases-dependent pathway activator in CRC cell line. These potentials support further exploratory molecular researches targeting the therapeutic roles of NTZ in CRC; individually and simultaneously with current approved chemotherapeutic regimens.

Herbal melanin inhibits colorectal cancer cell proliferation by altering redox balance, inducing apoptosis, and modulating MAPK signaling

Background

Colorectal carcinoma is one of the most deadly cancers that requests effective and safe chemotherapy. Evaluation of natural product-based anticancer drugs as adjuvant treatment with fewer side effects is largely unexplored research fields. Herbal melanin (HM) is an extract of the seed coats of Nigella sativa that modulates an inflammatory response through toll-like receptor 4 (TLR4). This TLR4 receptor is also involved in the modulation of apoptosis. We therefore explored the anticancer potential of HM and specifically its effect on the molecular mechanisms underlying adenocarcinoma and metastatic colorectal cancer (mCRC) cell death in vitro.

Methods

Cell viability was evaluated using the MTT assay. Cellular reactive oxygen species (ROS), glutathione levels, and apoptotic status were assessed using fluorometric and colorimetric detection methods. HM-induced apoptotic and other signaling pathways were investigated using Western blot technology and mitochondrial transition pore assay kit. TLR4 receptor downregulation and blockade were performed using siRNA technology and neutralizing antibody, respectively.

Results

Our results showed that HM inhibited the proliferation of the colorectal adenocarcinoma HT29 and mCRC SW620 cell lines. Furthermore, HM enhanced ROS production and decreased glutathione levels. HM-induced apoptosis was associated with mitochondrial outer membrane permeability and cytochrome c release, inhibition of the Bcl2 family proteins, and activation of caspase-3/-7. In addition, HM modulated MAPK pathways by activating the JNK pathway and by inhibiting ERK phosphorylation. TLR4 receptor downregulation enhanced HM-induced apoptosis while TLR4 receptor blockade partially alleviated HM-inhibited ERK phosphorylation.

Conclusion

Altogether, these findings indicate that HM exerts pro-apoptotic effects and inhibits MAPK pathway through TLR4 in mCRC and colorectal adenocarcinoma cells, suggesting HM as a promising natural-based drug for the treatment of colorectal cancer.

Propolis prevents inhibition of apoptosis by potassium bromate in CCD 841 human colon cell

Previously, we demonstrated that biotransformation of propolis by some special strains of Lactobacillus plantarum might decrease the allergenic molecules in propolis. In this study, we aimed to investigate the effect of biotransformation of propolis on its antioxidant effect and its protective effect against potassium bromate-induced cancer in human colon cell line. Propolis samples were treated with different solutions (ethanol, polyethylene glycol, and water), and ultrasonication was applied at 40 Hz (5, 10, and 15 minutes) in order to facilitate solvation of solid samples. Fermentations were performed by L. plantarum strains (ISLG-2, ATCC-8014, and Visbyvac). The phenolic content of propolis was determined with liquid chromatography-mass spectrometry/mass spectrometry (LCMS/MS). The antioxidant activity (antioxidant enzymes, lipid peroxidation) and apoptosis markers (caspase 3,8,9, cytochrome-c, tumour necrosis factor-related apoptosis-inducing ligand-R1 and R2 [TRAIL], and apoptosis protease activating factor-1 [APAF-1] levels) were determined in CCD 841-human colon cell line after induction of oxidative stress by potassium bromate. All propolis samples in different solvents induced apoptosis and 4 biotransformed (by L. plantarum ISL-2 strain and L. plantarum ATCC 8014 strain) propolis samples with low allergenic molecules demonstrated similar inductions of apoptosis in CCD841 cell line. In conclusion, reduction of allergenic molecules in propolis via biotransformation did not change the antioxidant and protective effects of propolis, and it is suggested as a potential therapeutic molecule in prevention of colon cancer caused by oxidative stress for all patients. SIGNIFICANCE OF THE STUDY: This study is the first investigation that shows protective effect of propolis against potassium bromate toxicity by means of decreasing lipid peroxidation and reversing the main molecule levels in intrinsic and extrinsic pathway of apoptosis. Biotransformed propolis samples by L. plantarum ISL-2 and ATCC 8014 strain with low allergen molecule content has also the same effect in potassium bromate toxicity in CCD841 colon cell. Our data contributed that propolis as a natural compound might be a good candidate due to its minimal toxicity and lack of any adverse effects to prevent carcinogenic effect of potassium bromate.

Aspirin enhances the sensitivity of colon cancer cells to cisplatin by abrogating the binding of NF-κB to the COX-2 promoter

Cisplatin is one of the most potent chemotherapeutic agents for the treatment of colon cancer. Nevertheless, the unavoidability of the notable toxicity and the development of the acquired resistance severely restricted its clinical application. Aspirin and some other non-steroidal anti-inflammatory drugs have been used to prevent colon tumorigenesis as chemopreventive agents. Here, we explored the possibility of aspirin as an adjuvant drug to boost the anti-cancer effect of cisplatin for colon cancer. We found that aspirin significantly enhanced the cisplatin-mediated inhibitions of cell proliferation, migration and invasion and the induction of apoptosis in colon cancer cells. The combined treatment of aspirin and cisplatin suppressed the expression of the anti-apoptotic protein Bcl-2 and the EMT-related proteins, up-regulated the levels of the cleaved PARP and Bax, and blocked the PI3K/AKT and RAF-MEK-ERK signaling pathway. In addition, we demonstrated that the enhanced effect of aspirin on the cisplatin-induced inhibition of tumor cell growth was also mediated through the suppression of the binding activity of NF-κB to the COX-2 promoter. The combination of aspirin and cisplatin effectively attenuated the translocation of NF-κB p65/p50 from the cytoplasm to the nucleus, and abrogated the binding of NF-κB p65/p50 to the COX-2 promoter, thereby down-regulating COX-2 expression and PGE₂ synthesis. Moreover, the in vivo study also verified the enhanced anti-tumor activity of such combined therapy in colon cancer by targeting the NF-κB/COX-2 signaling. Our results provided new insights into understanding the molecular mechanisms of aspirin in sensitizing cisplatin-mediated chemotherapeutic effect in colon cancer and indicated a great potential of this combined therapy for cancer treatment.

Dietary probiotic and metabolites improve intestinal homeostasis and prevent colorectal cancer

Metabolites from Lactobacillus casei display substantial antioxidant and anti-inflammatory activities, inhibit colorectal cancer cell proliferation and growth, and modulate gut microfloral composition, specifically reducing sulfidogenic bacteria.

Wheat Bran for Colon Cancer Prevention: The Synergy between Phytochemical Alkylresorcinol C21 and Intestinal Microbial Metabolite Butyrate

There is convincing evidence that consuming whole grains (WGs) may decrease the risk of colorectal cancer (CRC). Wheat bran (WB) is a rich source of dietary fiber and phytochemicals with health-promoting properties. However, the active components especially the interaction between different components in WG wheat have not been fully explored. Here, we investigated whether one of the major WB phytochemicals, alkylresorcinol (AR) C21, and the major active intestinal microbial metabolite of fiber, butyrate, could synergistically suppress human colon cancer cells. Our results demonstrated for the first time that the combination of C21 and butyrate synergistically inhibited the growth of human colon cancer cells and induced apoptosis. Further mechanistic studies demonstrated that the cotreatment of C21 and butyrate induced significant up-regulations in cleaved Poly(ADP-ribose) polymerase (PARP), cleaved caspase 3, p53 upregulated modulator of apoptosis (PUMA), cytochrome C, lipid-conjugated membrane-bound form of microtubule-associated protein 1A/1B-light chain 3 (LC3-II), and C/EBP homologous protein (CHOP) expressions, indicating the synergistic anticancer effects of C21 and butyrate were associated with induction of apoptosis, autophagy, and ER stress pathways. Notably, the C21 concentrations in the large intestinal tract of mice treated with human relevant doses of C21, were from 0.86 to 1.78 μmol/g, suggesting the C21 doses used in vitro may be achievable after daily WG wheat intake. These results provide novel insights into the dietary prevention of CRC regarding the potential interaction of bioactive WG wheat phytochemicals and the microbial metabolites of fiber.

α-Hederin Increases The Apoptosis Of Cisplatin-Resistant Gastric Cancer Cells By Activating Mitochondrial Pathway In Vivo And Vitro

INTRODUCTION

Gastric cancer remains an important cancer worldwide, and conventional chemotherapeutic drugs have the defects of drug resistance and cell toxicity. α-Hederin has been found to have certain therapeutic effects on various types of human cancers. However, studies on the α-hederin that exert biological activities on the cisplatin-resistant gastric cancer cells are limited. In this study, we evaluated the effects of α-hederin in HGC27/DDP and the potential mechanisms both in vivo and in vitro.

METHODS

HGC27/DDP cells were cultured in DMEM/F12 medium. Cell proliferation and viability were assessed quantitatively using Cell Counting Kit-8. Cell invasion and migration were detected by Transwell invasion assay and wound healing assay. Cell apoptosis was examined by employing Hoechst 33258 Staining Kit and an Annexin V-PE apoptosis kit. Intracellular GSH levels were examined by using a GSH Assay Kit. DCFH-DA and JC-1 Kit were used to detect levels of intracellular reactive oxygen species (ROS) and changes in mitochondrial membrane potential (∆Ψm). The protein levels of Apaf-1, AIF, Bax, Bcl-2, Cyt C, Survivin, cleaved caspase-3, cleaved caspase-9, MMP-9 and MMP-2 were detected by Western blot analysis. The effect of α-hederin in vivo was observed by xenograft tumor models in nude mice.

RESULTS

The α-hederin treatment significantly inhibited the proliferation in a dose- and time-dependent manner of HGC27/DDP and induced obvious apoptosis compared with the control group (P<0.05). Meanwhile, the ability of cells to invade and migrate was suppressed (P<0.05). The α-hederin induced the depletion of GSH (P<0.05) and the accumulation of intracellular ROS (P<0.05), changed the mitochondrial membrane potential (P<0.05), increased the Bax, Apaf-1, AIF, Cyt C, cleaved caspase-3 and cleaved caspase-9 expression and decreased the protein level of Bcl-2, survivin, MMP-9 and MMP-2 (P<0.05). Pretreatment with NAC (12 mM) enhanced the tendency and pretreatment with BSO (8 mM) attenuated the tendency above (P<0.05). Meanwhile, α-hederin inhibited xenograft tumor growth in vivo (P<0.05).

CONCLUSION

Our study provides strong molecular evidence to support our hypothesis that α-hederin inhibits the proliferation and induces the apoptosis of HGC27/DDP cells by increasing the levels of intracellular ROS and triggering mitochondrial pathway activation.

Wnt/β-catenin signaling pathway is involved in induction of apoptosis by oridonin in colon cancer COLO205 cells

Background

Oridonin has been demonstrated to have anticancer effect on all kinds of cancer cells and it has shown anti-tumor activity in some tumors partially via the inactivation of Wnt/β-catenin signaling pathway. The study investigated the anticancer effect of oridonin on colon carcinoma cell line COLO205 and explored underlying mechanism.

Methods

Cell Counting Kit-8 (CCK-8) assay was performed to assess cell viability. Flow cytometry was performed to analyze the apoptosis. The key target genes and proteins involved in Wnt/β-catenin pathway were detected by quantitative polymerase chain reaction (qPCR) and Western blotting. The xenograft tumor model of colon cancer COLO205 cell was introduced to detect anti-tumor effects in vivo. Transferase-mediated dUTP nick end labeling (TUNEL) assay was adopted to test the apoptotic cells in the tumor tissues.

Results

Oridonin inhibited the proliferation of colon cancer COLO205 cells in a dose-dependent and time-dependent manner. Oridonin induced apoptosis by increasing the cleavage of caspases in vitro. Furthermore, the expression levels of β-catenin and its downstream targets, including c-myc, cyclinD1 and survivin were significantly reduced. Nevertheless the knockdown of β-catenin by specific small interfering RNA (siRNA) could augment the anti-proliferative and pro-apoptotic effects by oridonin in COLO205 cells. Meanwhile, oridonin also increased protein expression level of glycogen synthase kinase 3β (GSK3β) and decreased the phosphorylation level of GSK3β. In vivo, oridonin treatment significantly suppressed tumor growth of COLO205 cell xenografts, and which was accompanied by the restrain of Wnt/β-catenin pathway.

Conclusions

Our present study demonstrated that the growth inhibition and apoptosis induction in colon cancer COLO205 cells by oridonin could be partially mediated through discontinuing Wnt/β-catenin signaling pathway.

BRD4 inhibitor and histone deacetylase inhibitor synergistically inhibit the proliferation of gallbladder cancer in vitro and in vivo

Gallbladder cancer (GBC) is the most common malignancy of the bile duct and has a high mortality rate. Here, we demonstrated that BRD4 inhibitor JQ1 and histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) synergistically inhibited the GBC cells in vitro and in vivo. Our results showed that cotreatment with JQ1 and SAHA significantly inhibited proliferation, cell viability and metastasis, and induced apoptosis and G2/M arrest in GBC cells, with only minor effects in benign cells. In vivo, tumor volumes and weights of GBC xenograft models were significantly decreased after treatment with JQ1 or SAHA; meanwhile, the cotreatment showed the strongest effect. Further study indicated that the above anticancer effects was associated with the downregulation of BRD4 and suppression of PI3K/AKT and MAPK/ERK pathways. These findings highlight JQ1 and SAHA as potential therapeutic agents and their combination as a promising therapeutic strategy for GBC.

The E3 ubiquitin ligase RNF40 suppresses apoptosis in colorectal cancer cells

Background

Colorectal cancer (CRC) is the fourth leading cause of cancer-related deaths worldwide, and deciphering underlying molecular mechanism is essential. The loss of monoubiquitinated histone H2B (H2Bub1) was correlated with poor prognosis of CRC patients and, accordingly, H2Bub1 was suggested as a tumor-suppressive mark. Surprisingly, our previous work revealed that the H2B ubiquitin ligase RING finger protein 40 (RNF40) might exert tumor-promoting functions. Here, we investigated the effect of RNF40 loss on tumorigenic features of CRC cells and their survival in vitro.

Methods

We evaluated the effects of RNF40 depletion in several human CRC cell lines in vitro. To evaluate cell cycle progression, cells were stained with propidium iodide and analyzed by flow cytometry. In addition, to assess apoptosis rates, caspase 3/7 activity was assessed in a Celigo® S-based measurement and, additionally, an Annexin V assay was performed. Genomic occupancy of H2Bub1, H3K79me3, and H3K27ac was determined by chromatin immunoprecipitation. Transcriptome-wide effects of RNF40 loss were evaluated based on mRNA-seq results, qRT-PCR, and Western blot. To rescue apoptosis-related effects, cells were treated with Z-VAD-FMK.

Results

Human CRC cell lines displayed decreased cell numbers in vitro after RNF40 depletion. While the differences in confluence were not mediated by changes in cell cycle progression, we discovered highly increased apoptosis rates after RNF40 knockdown due to elevated caspase 3/7 activity. This effect can be explained by reduced mRNA levels of anti-apoptotic and upregulation of pro-apoptotic BCL2 family members. Moreover, the direct occupancy of the RNF40-mediated H2B monoubiquitination was observed in the transcribed region of anti-apoptotic genes. Caspase inhibition by Z-VAD-FMK treatment rescued apoptosis in RNF40-depleted cells. However, knockdown cells still displayed decreased tumorigenic features despite the absence of apoptosis.

Conclusions

Our findings reveal that RNF40 is essential for maintaining tumorigenic features of CRC cells in vitro by controlling the expression of genes encoding central apoptotic regulators.

Electronic supplementary material

The online version of this article (10.1186/s13148-019-0698-x) contains supplementary material, which is available to authorized users.

Potential proapoptotic phytochemical agents for the treatment and prevention of colorectal cancer

Colorectal cancer (CRC) is one of the leading causes of mortality among men and women. Chemo-resistance, adverse effects and disease recurrence are major challenges in the development of effective cancer therapeutics. Substantial literature on this subject highlights that populations consuming diets rich in fibers, fruits and vegetables have a significantly reduced incidence rate of CRC. This chemo-preventive effect is primarily associated with the presence of phytochemicals in the dietary components. Plant-derived chemical agents act as a prominent source of novel compounds for drug discovery. Phytochemicals have been the focus of an increasing number of studies due to their ability to modulate carcinogenic processes through the alteration of multiple cancer cell survival pathways. Despite promising results from experimental studies, only a limited number of phytochemicals have entered into clinical trials. The purpose of the current review is to compile previously published pre-clinical and clinical evidence of phytochemicals in cases of CRC. A PubMed, Google Scholar and Science Direct search was performed for relevant articles published between 2008-2018 using the following key terms: 'Phytochemicals with colorectal cancers', 'apoptosis', 'cell cycle', 'reactive oxygen species' and 'clinical anticancer activities'. The present review may aid in identifying the most investigated phytochemicals in CRC cells, and due to the limited number of studies that make it from the laboratory bench to clinical trial stage, may provide a novel foundation for future research.

Mechanism of Apoptosis Induced by Curcumin in Colorectal Cancer

Colorectal cancer (CRC) is among the top three cancer with higher incident and mortality rate worldwide. It is estimated that about over than 1.1 million of death and 2.2 million new cases by the year 2030. The current treatment modalities with the usage of chemo drugs such as FOLFOX and FOLFIRI, surgery and radiotherapy, which are usually accompanied with major side effects, are rarely cured along with poor survival rate and at higher recurrence outcome. This trigger the needs of exploring new natural compounds with anti-cancer properties which possess fewer side effects. Curcumin, a common spice used in ancient medicine was found to induce apoptosis by targeting various molecules and signaling pathways involved in CRC. Disruption of the homeostatic balance between cell proliferation and apoptosis could be one of the promoting factors in colorectal cancer progression. In this review, we describe the current knowledge of apoptosis regulation by curcumin in CRC with regard to molecular targets and associated signaling pathways.