Treatment of LS174T colorectal cancer stem-like cells with n-3 PUFAs induces growth suppression through inhibition of survivin expression and induction of caspase-3 activation

Role of dietary intake of specific polyunsaturated fatty acids (PUFAs) on colorectal cancer risk in Iran

High-fat diets have been associated with colorectal cancer (CRC) risk, and the role of polyunsaturated fatty acids (PUFAs) has been reported to vary based on the length of PUFAs. We explored the association between dietary omega-6 and omega-3 PUFAs intake and CRC. We analyzed 865 CRC patients and 3206 controls from a case-control study of Iran (IROPICAN study). We used multivariate logistic regression models to calculate the odds ratios (OR) and 95% confidence intervals (CI) for the association between PUFAs intake and CRC risk. Our results showed that gamma-linolenic acid (18:3 n-6, GLA), arachidonic acid (20:4n-6, ARA), a-linolenic acid (Cis-18:3n-3, ALA), eicosapentaenoic acid (20:5n-3, EPA), docosahexaenoic acid (22:6n-3, DHA) consumption was not associated with the risk of CRC. However, the OR of linoleic acid (18: 2n-6, LA) intake was 1.47 (95% CI 1.01-2.14, p = 0.04) for proximal colon and that of docosapentaenoic acid (22:5n-3, DPA) intake was 1.33 (95% CI 1.05-1.69, p = 0.01) for rectum. This study indicates a high level of LA is associated with an increased risk of proximal colon cancer, and DPA intake was positively associated with rectum cancer risk. Furthermore, our study noted a high intake of n-6 (from vegetable oils) compared to n-3 PUFAs (from fish and seafood) in this population. Public awareness and government support is needed to increase fish and seafood production and consumption in Iran.

Molecular Mechanisms Associated with the Inhibitory Role of Long Chain n-3 PUFA in Colorectal Cancer

Colorectal cancer (CRC) is the third leading cause of cancer-related death in the world. Multiple evidence suggests that there is an association between excess fat consumption and the risk of CRC. The long chain n-3 polyunsaturated fatty acids (LC n-3 PUFA), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are essential for human health, and both in vitro and in vivo studies have shown that these fatty acids can prevent CRC development through various molecular mechanisms. These include the modulation of arachidonic acid (AA) derived prostaglandin synthesis, alteration of growth signaling pathways, arrest of the cell cycle, induction of cell apoptosis, suppression of angiogenesis and modulation of inflammatory response. Human clinical studies found that LC n-3 PUFA combined with chemotherapeutic agents can improve the efficacy of treatment and reduce the dosage of chemotherapy and associated side effects. In this review, we discuss comprehensively the anti-cancer effects of LC n-3 PUFA on CRC, with a main focus on the underlying molecular mechanisms.

The Involvement of Polyunsaturated Fatty Acids in Apoptosis Mechanisms and Their Implications in Cancer

Cancer is a significant global public health issue and, despite advancements in detection and treatment, the prognosis remains poor. Cancer is a complex disease characterized by various hallmarks, including dysregulation in apoptotic cell death pathways. Apoptosis is a programmed cell death process that efficiently eliminates damaged cells. Several studies have indicated the involvement of polyunsaturated fatty acids (PUFAs) in apoptosis, including omega-3 PUFAs such as alpha-linolenic acid, docosahexaenoic acid, and eicosapentaenoic acid. However, the role of omega-6 PUFAs, such as linoleic acid, gamma-linolenic acid, and arachidonic acid, in apoptosis is controversial, with some studies supporting their activation of apoptosis and others suggesting inhibition. These PUFAs are essential fatty acids, and Western populations today have a high consumption rate of omega-6 to omega-3 PUFAs. This review focuses on presenting the diverse molecular mechanisms evidence in both in vitro and in vivo models, to help clarify the controversial involvement of omega-3 and omega-6 PUFAs in apoptosis mechanisms in cancer.

Emerging Importance of Survivin in Stem Cells and Cancer: the Development of New Cancer Therapeutics

Survivin is one of the rare proteins that is differentially expressed in normal and cancer cells and is directly or indirectly involved in numerous pathways required for tumor maintenance. It is expressed in almost all cancers and its expression has been detected at early stages of cancer. These traits make survivin an exceptionally attractive target for cancer therapeutics. Even with these promising features to be an oncotherapeutic target, there has been limited success in the clinical trials targeting survivin. Only recently it has emerged that survivin was not being specifically targeted which could have resulted in the negative clinical outcome. Also, focus of research has now shifted from survivin expression in the overall heterogeneous tumor cell populations to survivin expression in cancer stem cells as these cells have proved to be the major drivers of tumors. Therefore, in this review we have analyzed the expression of survivin in normal and cancer cells with a particular focus on its expression in cancer stem cell compartment. We have discussed the major signaling pathways involved in regulation of survivin. We have explored the current development status of various types of interventions for inhibition of survivin. Furthermore, we have discussed the challenges involving the development of potent and specific survivin inhibitors for cancer therapeutics. Finally we have given insights for some of the promising future anticancer treatments.

Zinc, ω-3 polyunsaturated fatty acids and vitamin D: An essential combination for prevention and treatment of cancers

Zinc, ω-3 polyunsaturated fatty acids (PUFAs) and vitamin D are essential nutrients for health, maturation and general wellbeing. Extensive literature searches have revealed the widespread similarity in molecular biological properties of zinc, ω-3 PUFAs and vitamin D, and their similar anti-cancer properties, even though they have different modes of action. These three nutrients are separately essential for good health, especially in the aged. Zinc, ω-3 PUFAs and vitamin D are inexpensive and safe as they are fundamentally natural and have the properties of correcting and inhibiting undesirable actions without disturbing the normal functions of cells or their extracellular environment. This review of the anticancer properties of zinc, ω-3 PUFAs and vitamin D is made in the context of the hallmarks of cancer. The anticancer properties of zinc, ω-3 PUFAs and vitamin D can therefore be used beneficially through combined treatment or supplementation. It is proposed that sufficiency of zinc, ω-3 PUFAs and vitamin D is a necessary requirement during chemotherapy treatment and that clinical trials can have questionable integrity if this sufficiency is not checked and maintained during efficacy trials.

The Safe Soluble Compound Dehydroascorbic Acid Inhibits Various Upstream and Downstream Effectors of PI3K and KRAS Signaling Pathways in Undruggable PIK3CA/KRAS-Mutant Colorectal Cancer Stem-Like Cells

Efforts to develop effective drugs targeting PI3K and KRAS signaling pathways in PIK3CA/KRAS-mutant colorectal cancer stem cells (CRCSCs) remain challenging. Finding safe compounds that can easily enter CRCSCs with the ability to target metastasis-driver gene CXCR4 and pluripotency network genes as key upstream and downstream effectors of both PI3K and KRAS signaling pathways may provide promising results. PIK3CA/KRAS-mutant CRCSCs display high expression of glucose transporters (GLUTs) on their cell membrane and a glycolytic phenotype providing an opportunity to deliver antiglycolytic compounds into these cells via the GLUTs. CRC patients with low levels of vitamin C in their plasma show a shorter survival suggesting the ability of this vitamin at the physiologic levels for caspase-3 activation and apoptosis in CRCSCs. Vitamin C in an oxidized form (L-dehydroascorbic acid; L-DHA) with antiglycolytic activity can be taken up into CRC cells via the GLUTs. This may provide selective toxicity on CRCSCs and affect CXCR4 and stemness markers genes expression in these cells. To this end, we treated PIK3CA/KRAS-mutant LS174T cells with high glycolytic activity as an attractive model for CRCSCs with L-DHA equal to the pharmacological levels of vitamin C in human plasma, after which cell numbers, metabolic activity, proliferation-rate, CXCR4 and pluripotency network genes expression, caspase-3 activity with apoptosis were evaluated. 48 h post-treatment with 100- to 1000 µM L-DHA, cell numbers were decreased and measured to be 70-47% control. L-DHA with selective toxicity on LS174T cells diminished metabolic activity and cell proliferation-rate to 1.4-0.8 (Control OD = 1.5) and 92-54.5% respectively with no toxicity on PBMCs. L-DHA decreased CXCR4, Bmi-1, Sox-2 and Oct-4 expression to 45%, 85%, 45% and 48% control respectively followed by caspase-3 reactivation by 2.5 to 4.9-fold increases and induction of apoptosis ranging from 0.5% to 58.3% for 100- to 1000 µM L-DHA. According to our data, CRC stem-like cells were highly sensitive to L-DHA in in-vitro. L-DHA selectively targeted LS174T cells and successfully reactivated caspase-3 and apoptosis in these cells. CXCR4, stemness marker genes and metabolic activity appear to be promising targets of L-DHA. Our results may provide a new therapeutic approach to target selectively GLUT-overexpressing PIK3CA/KRAS-mutant CRCSCs using L-DHA with no toxicity on normal cells.

Cyclooxygenase activity mediates colorectal cancer cell resistance to the omega-3 polyunsaturated fatty acid eicosapentaenoic acid

Purpose

The naturally-occurring omega-3 polyunsaturated fatty acid eicosapentaenoic acid (EPA) is safe, well-tolerated and inexpensive, making it an attractive anti-cancer intervention. However, EPA has only modest anti-colorectal cancer (CRC) activity, when used alone. Both cyclooxygenase (COX) isoforms metabolise EPA and are over-expressed in CRC cells. We investigated whether COX inhibition increases the sensitivity of CRC cells to growth inhibition by EPA.

Methods

A panel of 18 human and mouse CRC cell lines was used to characterize the differential sensitivity of CRC cells to the growth inhibitory effects of EPA. The effect of CRISPR-Cas9 genetic deletion and pharmacological inhibition of COX-1 and COX-2 on the anti-cancer activity of EPA was determined using in vitro and in vivo models.

Results

Genetic ablation of both COX isoforms increased sensitivity of CT26 mouse CRC cells to growth inhibition by EPA in vitro and in vivo. The non-selective COX inhibitor aspirin and the selective COX-2 inhibitor celecoxib increased sensitivity of several human and mouse CRC cell lines to EPA in vitro. However, in a MC38 mouse CRC cell tumour model, with dosing that mirrored low-dose aspirin use in humans, thereby producing significant platelet COX-1 inhibition, there was ineffective intra-tumoral COX-2 inhibition by aspirin and no effect on EPA sensitivity of MC38 cell tumours.

Conclusion

Cyclooxygenase inhibition by non-steroidal anti-inflammatory drugs represents a therapeutic opportunity to augment the modest anti-CRC activity of EPA. However, intra-tumoral COX inhibition is likely to be critical for this drug-nutrient interaction and careful tissue pharmacodynamic profiling is required in subsequent pre-clinical and human studies.

Electronic supplementary material

The online version of this article (10.1007/s00280-020-04157-2) contains supplementary material, which is available to authorized users.

ω-3 and ω-6 Polyunsaturated Fatty Acids, Obesity and Cancer

Recently, nutraceutical bioactive compounds in foods have been discovered for their potential health benefits regarding the prevention of chronic disorders, such as cancer, and inflammatory, cardiovascular, and metabolic diseases. Dietary omega-3 polyunsaturated fatty acids (ω-3PUFAs), including alpha-linolenic acid, docosapentaenoic acid, and eicosapentaenoic acid, are mostly attractive. They are available for the customers worldwide from commonly used foods and/or as components of commercial food supplements. The anti-inflammatory and hypotriglyceridemic effects of these fatty acids are well known, whereas pro-inflammatory properties have been recognized in their dietary counterparts, the ω-6PUFAs. Both ω-3 and ω-6PUFAs contribute to the production of lipid mediators such as endocannabinoids that are notably involved in control of food intake, energy sensing, and food-related disorders. In this review, we present ω-3 and ω-6PUFAs and their derivatives, endocannabinoids; discuss the anti-obesity effects of ω-3PUFAs; their roles in inflammation and colorectal cancer development; and how their action can be co-preventative and co-therapeutic.

Omega-3 polyunsaturated fatty acids as adjuvant therapy of colorectal cancer

The majority of evidence linking anti-colorectal cancer (CRC) activity with omega-3 polyunsaturated fatty acids (O3FAs) has focussed on decreased CRC risk (prevention). More recently, preclinical data and human observational studies have begun to make the case for adjuvant treatment of advanced CRC. Herein, we review latest data regarding the effect of O3FAs on post-diagnosis CRC outcomes, including mechanistic preclinical data, evidence that O3FAs have beneficial effects on efficacy and tolerability of CRC chemotherapy, and human epidemiological data linking dietary O3FA intake with CRC outcomes. We also highlight ongoing randomised controlled trials of O3FAs with CRC endpoints and discuss critical gaps in the evidence base, which include limited understanding of the effects of O3FAs on the tumour microenvironment, the host immune response to CRC, and the intestinal microbiome.

Treatment with DHA Modifies the Response of MDA-MB-231 Breast Cancer Cells and Tumors from nu/nu Mice to Doxorubicin through Apoptosis and Cell Cycle Arrest

Background

Docosahexaenoic acid (DHA) has been shown to reduce growth of breast cancer cells in vitro and in vivo; it may also benefit the action of cytotoxic cancer drugs. The mechanisms for these observations are not completely understood.

Objectives

We sought to explore how pretreatment of MDA-MB-231 breast cancer cells with DHA alters gene expression with doxorubicin (DOX) treatment and confirm that feeding DHA to tumor-bearing nu/nu mice improves the efficacy of DOX.

Methods

MDA-MB-231 cells were subjected to 4 conditions: a control mixture of 40 μM linoleic and 40 μM oleic acid (OALA), DHA (60 μM plus OALA), OALA DOX (0.41 μM), or DHA DOX (plus OALA) and assessed for effects on viability and function. Female nu/nu mice (6 wk old) bearing MDA-MB-231 tumors were randomly assigned to a nutritionally complete diet (20 g ± 2.8 g DHA/100 g diet) containing a polyunsaturated:saturated fat ratio of 0.5, with or without injections 2 times/wk of 5 mg DOX/kg for 4 wk.

Results

Microarray and protein analysis indicated that DHA DOX cells, compared with OALA DOX, had upregulated expression of apoptosis genes, Caspase-10 (1.3-fold), Caspase-9 (1.4-fold), and Receptor (TNFRSF)-interacting serine-threonine kinase 1 (RIPK1) (1.2-fold), while downregulating cell cycle genes, Cyclin B1 (-2.1-fold), WEE1 (-1.6-fold), and cell division cycle 25 homolog C (CDC25C) (-1.8-fold) (P < 0.05). DHA DOX-treated mice had 50% smaller tumors than control mice (P < 0.05). Analysis of proapoptotic proteins from tumors of DHA DOX mice showed increased Caspase-10 (by 68%) and BH3 interacting domain death agonist (Bid) (by 50%), decreased B-cell CLL/lymphoma 2 (BCL2) (by 24%), and decreased cell cycle proteins Cyclin B1 and Cdc25c (both by 42%), compared with control mice (P < 0.05).

Conclusions

Supplementation with DHA facilitates the action of DOX in MDA-MB-231 cells and in nu/nu mice, which may occur via amplification of the effect of DOX on apoptosis and cell cycle genes.

The emerging role of lncRNAs in the regulation of cancer stem cells

BACKGROUND

Tumors contain a functional subpopulation of cells that exhibit stem cell properties. These cells, named cancer stem cells (CSCs), play significant roles in the initiation and progression of cancer. Long non-coding RNAs (lncRNAs) can act at the transcriptional, posttranscriptional and translational level. As such, they may be involved in various biological processes such as DNA damage repair, inflammation, metabolism, cell survival, cell signaling, cell growth and differentiation. Accumulating evidence indicates that lncRNAs are key regulators of the CSC subpopulation, thereby contributing to cancer progression. The aim of this review is to overview current knowledge about the functional role and the mechanisms of action of lncRNAs in the initiation, maintenance and regulation of CSCs derived from different neoplasms. These lncRNAs include CTCF7, ROR, DILC, HOTAIR, H19, HOTTIP, ATB, HIF2PUT, SOX2OT, MALAT-1, CUDR, Lnc34a, Linc00617, DYNC2H1-4, PVT1, SOX4 and ARSR Uc.283-plus. Furthermore, we will illustrate how lncRNAs may regulate asymmetric CSC division and contribute to self-renewal, drug resistance and EMT, thus affecting the metastasis and recurrence of different cancers. In addition, we will highlight the implications of targeting lncRNAs to improve the efficacy of conventional drug therapies and to hamper CSC survival and proliferation.

CONCLUSIONS

lncRNAs are valuable tools in the search for new targets to selectively eliminate CSCs and improve clinical outcomes. LncRNAs may serve as excellent therapeutic targets because they are stable, easily detectable and expressed in tissue-specific contexts.

Omega-3 fatty acid DHA modulates p53, survivin, and microRNA-16-1 expression in KRAS-mutant colorectal cancer stem-like cells

Background

The presence of chemotherapy-resistant colorectal cancer stem cells (CCSCs) with KRAS mutation is thought to be one of the primary causes for treatment failure in colorectal cancer (CRC). P53, survivin, and microRNA-16-1 are challenging targets for anticancer drugs which are associated with chemoresistance in CRC. Yet, no p53-, survivin-, and microRNA-16-1-modulating drug with low toxicity but high efficacy against KRAS-mutant CCSCs have been approved for clinical application in CRC. Here, we investigated whether in vitro concentrations of DHA equal to human plasma levels, are able to modulate, Wt-p53, survivin, and microRNA-16-1 in CRC cells with stem cell-like properties.

Methods

Wt-p53/KRAS-mutant CRC cells (HCT-116) with stem cell-like properties were treated with 100-, 150- and 200-μM/L DHA, after which cell number, viability, growth inhibition, Wt-p53, survivin and microRNA-16-1 expression, caspase-3 activation and apoptotic-rate were evaluated by different cellular and molecular techniques.

Results

After 24-, 48-, and 72-h treatments with 100- to 200-μM/L DHA, growth inhibition- rates were measured to be 54.7% to 59.7%, 73.% to 75.8%, and 63.3% to 97.7%, respectively. Treatment for 48 h with indicated DHA concentrations decreased cell number and viability. In addition, we observed a decrease in both the transcript and protein levels of survivin followed by 1.3- to 1.7- and 1.1- to 4.7-fold increases in the Wt-p53 accumulation and caspase-3 activation levels respectively. Treatment with 100 and 150 μM/L DHA increased microRNA-16-1 expression levels by 1.3- to 1.7-fold and enhanced the microRNA-16-1/survivin mRNA, p53/survivin, and caspase-3/survivin protein ratios by 1.7- to 1.8-, 1.3- to 2.6-, and 1.3- to 2-fold increases respectively. A decrease in the number of live cells and an increase in the number of apoptotic cells were also observed with increasing DHA concentrations.

Conclusion

Wt-p53, survivin, and microRNA-16-1 appear to be promising molecular targets of DHA. Thus, DHA might represent an attractive anti-tumor agent directed against KRAS-mutant CCSCs.

Overexpression of CCDC34 in colorectal cancer and its involvement in tumor growth, apoptosis and invasion

It has been previously reported that increased expression of coiled-coil domain containing 34 (CCDC34), a member of the CCDCs family, may promote the proliferation and invasion of bladder cancer cells. However, its role in colorectal cancer (CRC) remains unclear. The present study investigated CCDC34 expression in CRC tissues and determined the association between CCDC34 expression and biological characteristics in patients with CRC. Additionally, the variation of cell activity, apoptosis, invasion and associated mechanisms were evaluated following CCDC34 inhibition in SW620 cells with small interfering RNA (siRNA). The role of CCDC34 in CRC growth, apoptosis and invasion was investigated. In the current study, immunohistochemistry revealed an overexpression of CCDC34 in CRC tissues compared with paracancerous tissue (χ²=29.810; P<0.001). Furthermore, CCDC34 expression was revealed to be associated with tumor invasion depth and lymphatic metastasis (χ²=4.343, P=0.037; χ²=7.915, P=0.005). Additionally, the inhibition of CCDC34 expression in SW620 cells led to reduced tumor cell activity, increased apoptosis rate and reduced invasion ability, and expression of apoptosis and invasion-associated genes varied simultaneously which demonstrated that B cell leukemia/lymphoma 2, survivin, N-cadherin, and MMP-9 were decreased, whereas E-cadherin increased significantly in cells of CCDC34-siRNA group compared with the control group (P<0.05). Therefore, CCDC34 may contribute to CRC development by inhibiting apoptosis of cancer cells and promoting invasion.

Fish-oil-derived eicosapentaenoic acid decreases survivin expression and induces wt-p53 accumulation with caspase-3 activation in acute lymphoblastic leukemia cells

BACKGROUND

Defects in modulating wild-type (wt) p53 and survivin are associated with a resistant disease in acute lymphoblastic leukemia (ALL). Yet, no wt-p53 and survivin modulating drugs have been approved for clinical application in ALL. Here, we investigated if in vitro eicosapentaenoic acid (EPA) concentrations equal to human plasma levels are able to target wt-p53 and survivin.

METHODS

Wt-p53 Molt-4 cells (ALL cell line) were treated with 50, 100, 150, and 200 µM of EPA after which cell number, viability, proliferation rate, survivin expression, wt-p53 accumulation, caspase-3 activation, and apoptosis were evaluated.

RESULTS

After 48- and 72-h treatments with EPA at concentrations ranging from 50 to 200 µM, cell proliferation rates were measured to be 71.5-32.6% and 68.2-13.7% and metabolic activities were measured to be 77-44% and 71-26%, respectively. Treatment with 50-200 µM of EPA for 48 h resulted in 14.1-74.6% and 69.5-45.5% decreases in survivin mRNA and protein levels, respectively. EPA induced 1.3-6 and 1.9-20-fold increases in caspase-3 activation and wt-p53 accumulation, respectively. Increase in wt-p53/survivin and caspase-3/survivin ratios from 1 in untreated cells to 20.3 and 5.8 was measured for 150 µM of EPA. Low necrotic rates ranging from 0.3% to 2.8% and an increase in the number of total apoptotic cells (early + late) ranging from 9.8% to 81% were also observed with increasing EPA concentrations.

CONCLUSION

EPA induces strongly wt-p53 with a remarkable decrease in survivin expression, representing an attractive compound to modulate wt-p53 and survivin in ALL cells.

Cancer stem cell research in Iran: potentials and challenges

Treatment modalities can reduce cancer-related mortality; however, a majority of patients develop drug resistance, metastasis and relapse. It has been proposed that tumorigenic characteristics of tumors are related to a proportion of cancer cells, termed cancer stem cells (CSCs). Following the first evidence regarding the existence of CSC population in acute myeloid leukemia in 1997, publications in CSCs field showed an explosive trend in all cancer types around the world. First research paper in the field of CSCs in Iran was published in 2004 on prostate cancer. Subsequently, an annual number of publications in the field of CSCs displayed a rapidly growing trend. Therefore, in the current review, we have presented a comprehensive evaluation of the CSCs research in Iran.

The omega-3 polyunsaturated fatty acid docosahexaenoic acid inhibits proliferation and progression of non-small cell lung cancer cells through the reactive oxygen species-mediated inactivation of the PI3K /Akt pathway

BACKGROUND

Docosahexaenoic acid(DHA) inhibits tumor growth and progression in various cancers, including lung cancer. However, the mechanisms involved remain unclear. The aim of this study was to identify the mechanism of DHA in inhibiting progression of non-small cell lung cancer (NSCLC) in vitro.

METHODS

The proliferation of A549 was tested by MTT, and cell apoptosis was analysed using flow cytometer. The migration and invasion were examined respectively by wound healing assay and Transwell invasion assay. The level of ROS (reactive oxygen species, ROS) was checked by DCF (dichlorodihydrofluorescein, DCF) production in cells. The apoptosis associated protein (caspase-3, PARP,Bax,Bcl-2 and survivin) and metastases associated proteins including HEF1, MMP9 and VEGF were detected by Western blot, and the same method was used in the expression of PI3K and Akt.

RESULTS

DHA inhibited proliferation and induced apoptosis of A549 cells. Moreover, it suppressed the invasion and metastasis of A549 cells, while downregulating the levels of metastasis-associated proteins, including HEF1, matrix metallopeptidase (MMP9), and vascular endothelial growth factor (VEGF), in a dose -dependent manner. In addition, DHA inactivated Akt phosphorylation. All of these responses were associated with the accumulation of intracellular ROS. DHA downregulated the level of antioxidant enzymes such as catalase, while the antioxidant N-acetyl-cysteine (NAC) reversed the effect of DHA, which further validated our findings.

CONCLUSIONS

The present study demonstrates that DHA inhibits the development of non-small lung tumors through an ROS-mediated inactivation of the PI3K/Akt signaling pathway.

Effect of vitamin D3 derivative MART-10 on cell growth and expression of survivin mRNA, c-myc protein and P21 protein in BxPC-3 cells

AIM: To analyze the effect of MART-10, a new kind of vitamin D₃ derivative, on cell growth and proliferation and the expression of survivin mRNA, c-myc protein and P21 protein in BxPC-3 cells.

METHODS: After BxPC-3 cells were treated with MART-10, the growth of BxPC-3 cells was assessed by MTT assay, cell cycle was analyzed by flow cytometry, survivin mRNA level was detected by reverse transcription-polymerase chain reaction (RT-PCR), and c-myc and P21 protein expression was detected by Western blot.

RESULTS: Treatment with MART-10 significantly inhibited the growth of BxPC-3 cells, and the IC₅₀ concentration was 10^-7 mmol/L. Flow cytometry results suggested that the proportion of S phase cells was decreased and the proportion of cells in G₀/G₁ phase was increased after treatment with MART-10. RT-PCR results showed that MART-10 significantly downregulated the mRNA level of survivin gene. Western blot results indicated that MART-10 significantly increased the protein levels of P21 but decreased the protein expression of c-myc.

CONCLUSION: Our results suggest that MART-10 can effectively inhibit the growth and proliferation of BxPC-3 cells, and the mechanism may be related with its influence on the expression of survivin, c-myc and P21.