Inositol-6 phosphate inhibits the mTOR pathway and induces autophagy-mediated death in HT-29 colon cancer cells

Protamine 1 as a secreted colorectal cancer-specific antigen facilitating G1/S phase transition under nutrient stress conditions

PURPOSE

Cancer testis antigens (CTAs) are optimal tumor diagnostic markers and involved in carcinogenesis. However, colorectal cancer (CRC) related CTAs are less reported with impressive diagnostic capability or relevance with tumor metabolism rewiring. Herein, we demonstrated CRC-related CTA, Protamine 1 (PRM1), as a promising diagnostic marker and involved in regulation of cellular growth under nutrient deficiency.

METHODS

Transcriptomics of five paired CRC tissues was used to screen CRC-related CTAs. Capability of PRM1 to distinguish CRC was studied by detection of clinical samples through enzyme linked immunosorbent assay (ELISA). Cellular functions were investigated in CRC cell lines through in vivo and in vitro assays.

RESULTS

By RNA-seq and detection in 824 clinical samples from two centers, PRM1 expression were upregulated in CRC tissues and patients` serum. Serum PRM1 showed impressive accuracy to diagnose CRC from healthy controls and benign gastrointestinal disease patients, particularly more sensitive for early-staged CRC. Furthermore, we reported that when cells were cultured in serum-reduced medium, PRM1 secretion was upregulated, and secreted PRM1 promoted CRC growth in culture and in mice. Additionally, G1/S phase transition of CRC cells was facilitated by PRM1 protein supplementation and overexpression via activation of PI3K/AKT/mTOR pathway in serum deficient medium.

CONCLUSIONS

In general, our research presented PRM1 as a specific CRC antigen and illustrated the importance of PRM1 in CRC metabolism rewiring. The new vulnerability of CRC cells was also provided with the potential to be targeted in future. Diagnostic value and grow factor-like biofunction of PRM1 A represents the secretion process of PRM1 regulated by nutrient deficiency. B represents activation of PI3K/AKT/mTOR pathway of secreted PRM1.

Tanshinone IIA Regulates MAPK/mTOR Signal-Mediated Autophagy to Alleviate Atherosclerosis through the miR-214-3p/ATG16L1 Axis

Tanshinone IIA (Tan IIA), the core ingredient of Salvia miltiorrhiza, is commonly used for treating cardiovascular diseases. However, its underlying mechanism in regulating autophagy in atherosclerosis (AS) remains unclear. An in vivo model of AS was constructed using Apolipoprotein E-deficient (ApoE-/-) mice fed with a high-fat diet. Histopathologic changes and lipid accumulation were evaluated by hematoxylin and eosin (HE) and Oil red O staining, respectively. The inflammatory cytokine levels were evaluated by Enzyme-linked immunosorbent assay (ELISA). An oxidized low-density lipoprotein (ox-LDL) was used to induce foam cells in RAW264.7 cells. Cholesterol uptake and efflux assay were used to assess changes in intracellular and extracellular cholesterol levels. The expression levels of autophagy-related protein-16-like protein 1 (ATG16L1) and miR-214-3p in the samples and cells derived from mice were assessed by quantitative real-time polymerase chain reaction (qRT-PCR), and the protein levels of the mitogen-activated protein kinase (MAPK)/mammalian target of rapamycin (mTOR) and autophagy-related markers were detected using western blot. The binding site of miR-214-3p on ATG16L1 was determined using a dual-luciferase reporter assay. We observed a decrease in ATG16L1 and increase in miR-214-3p expression level in the AS mice and ox-LDL stimulated RAW264.7 cells. However, the miR-214-3p and ATG16L1 expression could be reversed by Tan IIA. In vivo experiments showed that Tan IIA alleviated AS by reducing lipid accumulation and inflammatory factor levels and promoting autophagy. The in vitro assays demonstrated that Tan IIA regulated lipid levels and autophagy via the miR-214-3p/ATG16L1 axis to inhibit foam cell formation. Additionally, Tan IIA inhibited the MAPK/mTOR pathway by reducing miR-214-3p expression and promoting autophagy. Findings from this study suggested that Tan IIA regulated the MAPK/mTOR signal-mediated autophagy to alleviate AS through the miR-214-3p/ATG16L1 axis.

Inositol Alleviates Pulmonary Fibrosis by Promoting Autophagy via Inhibiting the HIF-1α-SLUG Axis in Acute Respiratory Distress Syndrome

The effective remission of acute respiratory distress syndrome- (ARDS-) caused pulmonary fibrosis determines the recovery of lung function. Inositol can relieve lung injuries induced by ARDS. However, the mechanism of myo-inositol in the development of ARDS is unclear, which limits its use in the clinic. We explored the role and mechanism of myo-inositol in the development of ARDS by using an in vitro lipopolysaccharide- (LPS-) established alveolar epithelial cell inflammation model and an in vivo ARDS mouse model. Our results showed that inositol can alleviate the progression of pulmonary fibrosis. More significantly, we found that inositol can induce autophagy to inhibit the progression pulmonary fibrosis caused by ARDS. In order to explore the core regulators of ARDS affected by inositol, mRNA-seq sequencing was performed. Those results showed that transcription factor HIF-1α can regulate the expression of SLUG, which in turn can regulate the key gene E-Cadherin involved in cell epithelial-mesenchymal transition (EMT) as well as N-cadherin expression, and both were regulated by inositol. Our results suggest that inositol activates autophagy to inhibit EMT progression induced by the HIF-1α/SLUG signaling pathway in ARDS, and thereby alleviates pulmonary fibrosis.

Rhein Suppresses Colorectal Cancer Cell Growth by Inhibiting the mTOR Pathway In Vitro and In Vivo

Colorectal cancer (CRC) is one of the leading causes of mortality and morbidity in the world. Rhein has demonstrated therapeutic effects in various cancer models. However, its effects and underlying mechanisms of action in CRC remain poorly understood. We investigated the potential anticancer activity and underlying mechanisms of rhein in CRC in vitro and in vivo. Cell viability and anchorage-independent colony formation assays were performed to examine the antigrowth effects of rhein on CRC cells. Wound-healing and Transwell assays were conducted to assess cell migration and invasion capacity. Cell cycle and apoptosis were investigated by flow cytometry and verified by immunoblotting. A tissue microarray was used to detect mTOR expression in CRC patient tissues. Gene overexpression and knockdown were done to analyze the function of mTOR in CRC. The anticancer effect of rhein in vivo was assessed in a CRC xenograft mouse model. The results show that rhein significantly inhibited CRC cell growth by inducing S-phase cell cycle arrest and apoptosis. Rhein inhibited CRC cell migration and invasion through the epithelial-mesenchymal transition (EMT) process. mTOR was highly expressed in CRC cancer tissues and cells. Overexpression of mTOR promoted cell growth, migration, and invasion, whereas mTOR knockdown diminished these phenomena in CRC cells in vitro. In addition, rhein directly targeted mTOR and inhibited the mTOR signaling pathway in CRC cells. Rhein promoted mTOR degradation through the ubiquitin-proteasome pathway. Intraperitoneal administration of rhein inhibited HCT116 xenograft tumor growth through the mTOR pathway. In conclusion, rhein exerts anticancer activity in vitro and in vivo by targeting mTOR and inhibiting the mTOR signaling pathway in CRC. Our results indicate that rhein is a potent anticancer agent that may be useful for the prevention and treatment of CRC.

Autophagy is a double-edged sword in the therapy of colorectal cancer

Colorectal cancer is one of the leading causes of cancer-associated mortality worldwide. The limitations of colorectal cancer treatment include various types of multidrug resistance and the contingent damage to neighboring normal cells caused by chemotherapy. Macroautophagy/autophagy and apoptosis are essential mechanisms involved in cancer cell regulation of chemotherapy. Autophagy can either cause cancer cell death or promote tumor survival during colorectal cancer. Given that autophagy is involved in chemotherapy of colorectal cancer, an improved insight into the potential interactions between apoptosis and autophagy is crucial. The present review aimed to summarize the involvement of autophagy in the regulation of colorectal cancer and its association with chemotherapy. Furthermore, the role of natural product extraction, novel chemicals and small molecules, as well as radiation, which induce autophagy in colorectal cancer cells, were reviewed. Finally, the present review aimed to provide an outlook for the regulation of autophagy as a novel approach to the treatment of cancer, particularly chemotherapy-resistant colorectal cancer.

Resveratrol promotes apoptosis and G2/M cell cycle arrest of fibroblast-like synoviocytes in rheumatoid arthritis through regulation of autophagy and the serine-threonine kinase-p53 axis

Introduction

Resveratrol, a polyphenol extracted from many plant species, has emerged as a promising pro-apoptotic agent in various cancer cells. However, the role of resveratrol in cell proliferation and apoptosis of fibroblast-like synoviocytes in rheumatoid arthritis (RA-FLS) is not fully understood. The study was aimed at elucidating the role of resveratrol in cell proliferation and apoptosis of RA-FLS and the underlying molecular mechanism.

Material and methods

Cultured RA-FLSs were subjected to tumour necrosis factor α (TNF-α). The cell proliferation was measured by Cell Counting Kit-8 assay. Cell apoptosis and cell cycle of RA-FLSs were determined by flow cytometry. The levels of apoptosis or autophagy or cell cycle-related protein were detected by immunoblot analysis.

Results

In our study, we confirmed that resveratrol reversed TNF-α mediated cell proliferation in RA-FLS. Meanwhile, resveratrol blocked cells at the G2/M stage and reduced the ratio of S phase cells through upregulation of p53 and consequently led to apoptotic cell death. Quite interestingly, we found that resveratrol reversed TNF-α-induced autophagy. Inhibition of autophagy by resveratrol or autophagy inhibitor or Beclin-1 siRNA suppressed TNF-α mediated cell survival and promoted cell apoptosis. However, the autophagy inducer rapamycin (RAPA) reversed the effect of resveratrol on autophagy and cell proliferation. Mechanistic studies revealed that resveratrol inhibited the activation of the phosphoinositide 3-kinases/serine-threonine kinase (PI3K/AKT) pathway. Inhibition of PI3K/AKT pathway by inhibitor LY294002 or resveratrol increased the expression of p53 and decreased the expression of cycle protein (cyclin B1), which further led to block cells in the G2/M arrest.

Conclusions

Our preliminary study indicated that resveratrol may suppress RA-FLS cell survival and promote apoptosis at least partly through regulation of autophagy and the AKT-p53 axis.

Chemoprotective effects of inositol hexaphosphate against cyclophosphamide-induced testicular damage in rats

Cyclophosphamide (CP) is commonly used as an anticancer agent but has been associated with high toxicity in several animal organs, including the testes. Inositol hexaphosphate (IP6) is a polyphosphorylated carbohydrate that is present in foods with high fibre contents and has a wide range of essential physiological and pathological activities. Thus, we estimated the defensive effects of IP6 against CP-related testicular toxicity in rats. Sperm counts, motilities, viabilities and abnormalities and levels of testosterone, luteinising hormone and follicle-stimulating hormone were evaluated. Testicle specimens were also processed for histological and biochemical analyses, including determinations of malondialdehyde, nitric oxide, total antioxidant capacity, alkaline phosphatase, acid phosphatase, gamma glutamyl transferase, ß-glucuronidase, c-reactive protein, monocyte chemoattractant protein and leukotriene-4 and in comet assays. CP treatments were associated with deleterious histopathological, biochemical and genetic changes in rat testicles, and these were ameliorated by IP6 supplements in drinking water.

Expression of Notch pathway components (Numb, Itch, and Siah-1) in colorectal tumors: A clinicopathological study

BACKGROUND

The role of the Notch pathway in carcinogenesis and tumor progression has been demonstrated in many organs, including the colon. Accordingly, studies aimed at developing therapies targeting this pathway in various cancers require the identification of several factors that may play a role in regulating Notch-1 expression. Although Numb, Itch, and seven in absentia homolog-1 (Siah-1) have been shown to contribute to the regulation of Notch signaling, their role in colorectal carcinogenesis and tumor progression has not been fully elucidated to date.

AIM

To evaluate Numb, Itch, and Siah-1 expression in colorectal tumors to clarify their relationship with Notch-1 expression and their role in carcinogenesis and tumor behavior.

METHODS

Expression of Notch-1, Numb, Itch, and Siah-1 was investigated in 50 colorectal carcinomas, 30 adenomas, and 20 healthy colonic tissues by immunohistochemistry and quantitative real-time polymerase chain reaction (PCR) analyses.

RESULTS

In contrast to Notch-1, which is expressed at higher levels in tumor tissues and adenomas, expression of Numb, Itch, and Siah-1 was stronger and more frequent in normal mucosa (P < 0.01). There was a positive correlation between Notch-1 expression and high histological grade, the presence of lymph node metastasis, and advanced-stage tumors, whereas expression of Numb, Itch, and Siah-1 was absent or reduced in tumors with these clinicopathological parameters (P < 0.05). In survival analysis, expression of Notch was related to poor prognosis but that of Numb, Itch, and Siah-1 correlated with improved survival (P < 0.05). Multivariate analysis revealed Notch-1 expression and loss of Numb expression to be independent prognostic parameters together with lymph node metastasis (P < 0.05).

CONCLUSION

Our findings support the role of Notch-1 in colorectal carcinoma and indicate that loss of Numb, Itch, and Siah-1 expression is associated with carcinogenesis. Our data also suggest that these three proteins might be involved in the Notch-1 pathway during colorectal carcinoma (CRC) progression and might play an essential role in approaches targeting Notch as novel molecular therapies for CRC.

Combination of Inositol Hexaphosphate and Inositol Inhibits Liver Metastasis of Colorectal Cancer in Mice Through the Wnt/β-Catenin Pathway

Introduction

Colorectal cancer, one of the most common tumors, is mainly fatal because of the occurrence of liver metastasis. Inositol hexaphosphate (IP6) and inositol (INS) were found, both, in vitro and in vivo to play an anti-tumor effect, whereas the combination of IP6 and INS was more effective than IP6 or INS alone.

Materials and Methods

The inhibitory effects of IP6, INS and the combination of IP6+INS on tumor progression and liver metastasis of colorectal cancer were investigated in an orthotopic transplantation model of colorectal cancer. The tumor-bearing mice were selected by in vivo bioluminescence imaging and were treated with IP6, INS, and IP6 combined with INS, respectively. All mice were sacrificed after 6 weeks of treatment. The cancer development and metastasis were compared among the groups. The expression of genes related to the Wnt/β-catenin in the model was analyzed.

Results

The results demonstrated that liver metastasis was inhibited after treatment with IP6, INS, and IP6+INS. Compared to that of the M_G, survival period was extended, and tumor weight was lowered in IP6_G, INS_G, and IP6+INS_G. Besides, the liver metastatic area of mice in IP6+INS_G was relatively smaller than that in M_G, IP6_G, or INS_G. The results of RNA-seq analysis showed that the expressions of Wnt10b, Tcf7, and c-Myc were significantly downregulated in IP6+INS_G compared to that in M_G (P<0.05). Results of real-time PCR and Western blot showed that mRNA and protein expressions of β-catenin, Wnt10b, Tcf7, and c-Myc were significantly lower in IP6+INS_G compared to that in M_G (P<0.05).

Discussion

IP6+INS was more effective in inhibiting liver metastasis of colorectal cancer than IP6 or INS alone. The better inhibition effect may be accomplished through regulating the mutation of Wnt/β-catenin signaling pathway by inhibiting Wnt10b, Tcf7, β-catenin, and c-Myc from abnormally high expression.

Phytochemicals and Gastrointestinal Cancer: Cellular Mechanisms and Effects to Change Cancer Progression

Gastrointestinal (GI) cancer is a prevailing global health disease with a high incidence rate which varies by region. It is a huge economic burden on health care providers. GI cancer affects different organs in the body such as the gastric organs, colon, esophagus, intestine, and pancreas. Internal and external factors like smoking, obesity, urbanization, genetic mutations, and prevalence of Helicobacter pylori and Hepatitis B and Hepatitis C viral infections could increase the risk of GI cancer. Phytochemicals are non-nutritive bioactive secondary compounds abundantly found in fruits, grains, and vegetables. Consumption of phytochemicals may protect against chronic diseases like cardiovascular disease, neurodegenerative disease, and cancer. Multiple studies have assessed the chemoprotective effect of selected phytochemicals in GI cancer, offering support to their potential towards reducing the pathogenesis of the disease. The aim of this review was to summarize the current knowledge addressing the anti-cancerous effects of selected dietary phytochemicals on GI cancer and their molecular activities on selected mechanisms, i.e., nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), detoxification enzymes, adenosine monophosphate activated protein kinase (AMPK), wingless-related integration site/β-catenin (wingless-related integration site (Wnt) β-catenin, cell apoptosis, phosphoinositide 3-kinases (PI3K)/ protein kinase B AKT/ mammalian target of rapamycin (mTOR), and mitogen-activated protein kinase (MAPK). In this review phytochemicals were classified into four main categories: (i) carotenoids, including lutein, lycopene, and β-carotene; (ii) proanthocyanidins, including quercetin and ellagic acid; (iii) organosulfur compounds, including allicin, allyl propyl disulphide, asparagusic acid, and sulforaphane; and (iv) other phytochemicals including pectin, curcumins, p-coumaric acid and ferulic acid. Overall, phytochemicals improve cancer prognosis through the downregulation of β-catenin phosphorylation, therefore enhancing apoptosis, and upregulation of the AMPK pathway, which supports cellular homeostasis. Nevertheless, more studies are needed to provide a better understanding of the mechanism of cancer treatment using phytochemicals and possible side effects associated with this approach.

MiR-345-5p inhibits tumorigenesis of papillary thyroid carcinoma by targeting SETD7

INTRODUCTION

This study aimed to explore the effects of miR-345-5p on papillary thyroid carcinoma (PTC) and uncover the possible mechanisms.

MATERIAL AND METHODS

MiR-345-5p and SETD7 mRNA levels were analyzed by quantitative real-time PCR and SETD7 protein level was measured by Western blot. The viability, colony formation ability and apoptosis of PTC cells were measured with CCK-8, soft agar colony formation and flow cytometry assay, respectively. Luciferase reporter assay was used to identify miR-345-5p's target.

RESULTS

Compared to neighboring normal tissues, there was lower miR-345-5p expression and higher SETD7 expression in PTC tissues. Moreover, Spearman's correlation analysis indicated that there was a negative correlation between miR-345-5p and SETD7 expression in PTC tissues. MiR-345-5p mimics inhibited the viability and colony formation of TPC1 and B-CPAP cells and promoted apoptosis, whereas anti-miR-345-5p promoted PTC cell proliferation and inhibited apoptosis. SETD7 was confirmed to be a direct target of miR-345-5p through target scan analysis and luciferase reporter assay. Additionally, overexpression of SETD7 promoted the viability and colony formation of TPC1 and B-CPAP cells and inhibited apoptosis, whereas downregulation of SETD7 by shRNAs had opposite effects on PTC cells. Furthermore, overexpression of SETD7 attenuated the miR-345-5p induced anti-tumor effects on PTC cells.

CONCLUSIONS

MiR-345-5p exhibited suppressive effects on PTC via targeting SETD7.

miR-133a-3p promotes apoptosis and induces cell cycle arrest by targeting CREB1 in retinoblastoma

INTRODUCTION

Retinoblastoma (RB) is a malignant tumor that is derived from photoreceptors. It is common in children under 3 years old with a family genetic predisposition. MicroRNA-133a-3p (miR-133a-3p) is one of the tumor-related miRNAs that interprets a critical function in the genesis and development of various tumors. This study investigated the effects and underlying mechanisms of miR-133a-3p in RB.

MATERIAL AND METHODS

Quantitative reverse-transcription polymerase chain reaction (qRT-PCR) analysis was used to assess the miR-133a-3p expression in RB tissues and a cell model. MTT assay, western blot, flow cytometry and luciferase reporter assay were performed to evaluate the effect of miR-133a-3p on cell viability, apoptosis and the cell cycle. An RB xenograft model was established to assess the in vivo influence of miR-133a-3p on RB growth.

RESULTS

MiR-133a-3p level was reduced in RB tissues and the cell model (p < 0.01 or p < 0.001). Addition of miR-133a-3p reduced cell viability, and increased apoptosis and cell cycle arrest (p < 0.001). Additionally, CREB1 was identified to be the target of miR-133a-3p in RB cell lines (p < 0.001). Cell viability reduction, apoptosis and cell cycle arrest increases mediated by miR-133a-3p were attenuated by CREB1 overexpression (p < 0.001). MiR-133a-3p inhibited tumor growth of RB in vivo (p < 0.001).

CONCLUSIONS

Our results reveal that miR-133a-3p exhibits anti-cancer effects by targeting CREB1 in RB. This study provides a new direction for effective targeted treatment of this disease.

Ketamine exhibits anti-gastric cancer activity via induction of apoptosis and attenuation of PI3K/Akt/mTOR

INTRODUCTION

Gastric cancer (GC) is the most widespread type of cancer after lung and liver cancer in men and after breast cancer in women. Thus, the present study was intended to evaluate the effect of ketamine (KET) on gastric cancer cells.

MATERIAL AND METHODS

The effect of KET was analyzed in vitro by the MTT assay against human gastric cancer cell lines BGC-823, MKN-45 and MKN-28. The effect KET on apoptosis, cell migration and cell cycle arrest was also quantified. Western blot analysis was performed to estimate the effect of KET on apoptosis mediators and PI3K/AKT/mTOR pathway mediators. A mouse xenograft assay was also conducted to further confirm the anticancer activity.

RESULTS

KET causes reduction of cellular viability of BGC-823, MKN-45 and MKN-28, with a more significant effect against BGC-823 cells. The KET treatment showed a dose-dependent increase in apoptotic cells among BGC-823 cells. KET causes a significant dose-dependent decline in migration of treated cells. It causes induction of apoptosis mediated via the mitochondrial pathway, where it causes a decline in Bcl2 and mitochondrial cytochrome c level together with increase in expression of Bax, cytosolic cytochrome c and cytosolic apoptotic protease activating factor-1 (Apaf-1). The level of p-PI3K, p-mTOR, p-GSK3β and p-AKT was found to be downregulated in a dose-dependent manner in KET-treated cells. In a mouse xenograft model, KET causes a reduction in relative tumour volume and tumour weight.

CONCLUSIONS

Our results suggest that ketamine has the ability to inhibit progression of gastric cancer via induction of apoptosis and attenuation of PI3K/Akt/mTOR.

Allicin attenuates pathological cardiac hypertrophy by inhibiting autophagy via activation of PI3K/Akt/mTOR and MAPK/ERK/mTOR signaling pathways

BACKGROUND

Cardiac hypertrophy is an adaptive response of the myocardium to pressure or volume overload. Recent evidences indicate that allicin can prevent cardiac hypertrophy. However, it is not clear whether allicin alleviates cardiac hypertrophy by inhibiting autophagy.

PURPOSE

We aimed to investigate the effects of allicin on pressure overload-induced cardiac hypertrophy, and further to clarify the related mechanism.

STUDY DESIGN/METHODS

Cardiac hypertrophy was successfully established by abdominal aortic constriction (AAC) in rats, and cardiomyocytes hypertrophy was simulated by angiotensin II (Ang II) in vitro. Hemodynamic parameters were monitored by organism function experiment system in vivo. The changes of cell surface area were observed using HE and immunofluorescence staining in vivoand in vitro, respectively. The expressions of cardiac hypertrophy relative protein (BNP and β-MHC), autophagy marker protein (LC3-II and Beclin-1), Akt, PI3K and ERK were detected by western blot.

RESULTS

Allicin could improve cardiac function, and reduce cardiomyocytes size, and decrease BNP and β-MHC protein expressions. Further results showed that allicin could lower LC3-II and Beclin-1 protein expressions both in vivo and in vitro experiments. And pharmacological inhibitor of mTOR, rapamycin could antagonize the effects of allicin on Ang II-induced cardiac hypertrophy and autophagy. Simultaneously, allicin could promote the expressions of p-Akt, p-PI3K and p-ERK protein.

CONCLUSION

These findings reveal a novel mechanism of allicin attenuating cardiac hypertrophy which allicin could inhibit excessive autophagy via activating PI3K/Akt/mTOR and MAPK/ERK/mTOR signaling pathways.