The effects of purslane consumption on lipid profile and C-reactive protein: A systematic review and dose-response meta-analysis

Earlier investigations into the impact of purslane, Portulaca oleracea, on lipid profile and C-reactive protein (CRP) produced contradictory findings. The effect of purslane consumption on lipid profiles and CRP was assessed in this comprehensive review and meta-analysis. We conducted a thorough literature search in online databases, including PubMed, Scopus, the Cochrane library, and ISI Web of Science to find relevant randomized controlled trials up to June 2023. By incorporating 14 effect sizes from 13 RCTs, we were able to show that purslane consumption significantly decreases serum triglyceride (TG) (WMD: -16.72, 95% CI: -22.49, -10.96 mg/dL, p < .001), total cholesterol (TC) (WMD: -9.97, 95% CI: -19.86, -0.07 mg/dL, p = .048), and CRP (WMD: -1.22, 95% CI: -1.63, -0.80 mg/L, p < .001) levels in patients compared to the control group. In addition, purslane consumption significantly increases high-density lipoprotein (HDL-C) (WMD: 4.09, 95% CI: 1.77, 6.41 mg/dL, p = .001) levels. However, purslane consumption did not affect low-density lipoprotein (LDL-C) levels. According to a suggested optimal dosage, purslane consumption is considered to be safe up to 30 g/day. Purslane consumption can significantly improve cardiovascular health by improving lipid profile and inflammation status.

Exosomes as novel biomarkers in metabolic disease and obesity-related cancers

Exosomes include plasma-transported vesicles that are secreted by human tissues and reflect metabolic status. The profile of exosomes (particularly microRNA content) is altered in metabolic disease. In type 2 diabetes mellitus, exosomes circulating in plasma induce transcriptional changes related to tumour progression and pro-metastatic phenotypes in target cancer cells, potentially linking obesity to cancer progression and metastasis.

Abstract P1-04-12: Pathway analysis of immune checkpoint gene regulation as altered in Type 2 diabetes: Implications for breast cancer patients treated with checkpoint inhibitors

Background: Mediators of immune exhaustion are an active area of breast cancer research. Type II diabetes mellitus (T2D), the most common metabolic disorder, both increases breast cancer incidence and decreases survival. Despite this clear link, impacts of the T2D immune phenotype on cancer remain poorly understood. We have previously demonstrated that the chronic inflammatory state of T2D leads to immune exhaustion, but how the T2D breast microenvironment interacts with T cells is unclear. Exosomes are crucial components of intercellular communication and are associated with increased breast cancer aggressiveness. Given this function, we hypothesized that T2D adipocyte-derived exosomes drive T cell exhaustion. Here, we characterize expression patterns and regulatory networks driving T2D immune phenotypes. Methods: Exosomes were first isolated from culture media of mature human primary breast adipocytes from, either insulin-sensitive (IS), or rendered insulin-resistant (IR) by ex vivo TNFα-treatment. Human primary peripheral blood mononuclear cells (PBMCs) from nondiabetic (ND) and T2D donors were stimulated ex vivo with plate bound anti-CD3 (5 ug/ml) and soluble CD28 (2 ug/ml) for 48 hours and treated with exosomes. Different small molecule inhibitors of the bromo and extraterminal (BET) protein family, including the pan-BET inhibitor JQ1 and the BRD4-selective PROTAC degrader MZ-1, were used to identify BET protein-regulated targets. We also used the AMP-activating protein kinase (AMPK) inhibitor Compound-C to identify the role of this pathway in activating this major epigenetic player. Multicolor flow cytometry was subsequently performed with an LSRII cytometer to assess expression of inhibitory receptors PD-1, CTLA-4, TIM-3 and TIGIT on immune subsets. Events for live cells were analyzed in FlowJo. Cytokines were collected from conditioned media and analyzed via Th17 cytokine staining panel. Results: We observed that exosomes derived from IR breast adipocytes increase expression of immune exhaustion markers in CD4+ and CD8+ T cells, compared to IS or ND matched controls. Additionally, we define signal transduction among BET proteins, AMPK signaling, and immune checkpoint expression. Lastly, we identify changes in cytokine profile between IS and IR treated groups. Taken together, our findings suggest a network of immune regulation imparted by exosomes. Impacts: Metabolic health does not inform the current standard of care in breast medical oncology, which contributes to a large, underserved population in which treatment plans are not well established or optimized for their comorbidities. Our findings offer a deeper understanding of immune checkpoint regulation in T2D and suggest new insights into treatment of diabetic breast cancer patients.

Citation Format: Christina S. Ennis, Pablo LLevenes, Manohar Kolla, Naser Jafari, Anna C Belkina, Gerald V. Denis. Pathway analysis of immune checkpoint gene regulation as altered in Type 2 diabetes: Implications for breast cancer patients treated with checkpoint inhibitors [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-04-12.

Abstract P3-06-02: Exosomes produced by adipocytes induce EMT, immune exhaustion and tumor metastasis, in both in vivo and in vitro models of TNBC

Type 2 Diabetes (T2D) is a chronic inflammatory disease characterized by inflamed adipose tissue. Patients with triple negative breast cancer (TNBC) and comorbid T2D have higher risk of metastasis and shorter survival. However, mechanisms that couple T2D to TNBC outcomes are unknown. Here we hypothesize that exosomes, small vesicles secreted by tumor microenvironment breast adipocytes, drive epithelial-to-mesenchymal transition (EMT) in TNBC, immune exhaustion and metastasis via Ampk-Akt signaling.Methods: Exosomes were purified from conditioned media of 3T3-L1 mature adipocytes that were insulin-sensitive (IS) or insulin-resistant (IR), then characterized and quantified by NanoSight and surface markers, CD63. Murine 4T1 cells, a TNBC model, were treated with exosomes in vitro (3 days). To establish 3D organoids, 4T1 spheroids were treated with exosomes and embedded in Matrigel. For in vivo models, mammary fat pads of BALB/c mice were injected with 4T1 cells treated with IS vs IR exosomes. 4T1 tumors were harvested and mRNA extracted for qPCR, RNAseq, and Ingenuity Pathway Analysis. Metastatic sites in lung and liver were visualized by H&E staining and clonogenic assay. Immune exhaustion markers of tumor infiltrated lymphocytes (TILs) were measured by flow cytometry. Results: In 4T1 cells treated with IR exosomes, EMT was upregulated and PD-L1 expression increased. Tumor-bearing mice exhibited metastasis in exosome-treated groups, visualized by microscopy and clonogenic assay. Immune exhaustion markers showed modified expression in TILs from exosome-treated groups. RNA-seq analysis revealed differences among exosome-treated groups that suggest dysregulated Ampk-Akt pathways.Conclusion: Exosomes from IR adipocytes modify the tumor microenvironment, increase EMT and immune exhaustion markers on tumor cells and TILs, and promote metastasis to distant organs through Ampk-Akt. Metabolic diseases such as T2D reshape the TNBC tumor microenvironment, promoting metastasis and decreasing survival. Clearly, TNBC patients with T2D should be more closely monitored for metastasis than metabolically normal patients, with metabolic medications considered.

Citation Format: Yuhan Qiu, Conor Ross, Naser Jafari, Manohar Kolla, Pablo Llevenes, Christina Ennis, Carla S Mazzeo, Kiana Mahdaviani, Naomi Y Ko, Gerald V Denis. Exosomes produced by adipocytes induce EMT, immune exhaustion and tumor metastasis, in both in vivo and in vitro models of TNBC [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-06-02.

Adipocyte-derived exosomes may promote breast cancer progression in type 2 diabetes

Obesity and metabolic diseases, such as insulin resistance and type 2 diabetes (T2D), are associated with metastatic breast cancer in postmenopausal women. Here, we investigated the critical cellular and molecular factors behind this link. We found that primary human adipocytes shed extracellular vesicles, specifically exosomes, that induced the expression of genes associated with epithelial-to-mesenchymal transition (EMT) and cancer stem–like cell (CSC) traits in cocultured breast cancer cell lines. Transcription of these genes was further increased in cells exposed to exosomes shed from T2D patient–derived adipocytes or insulin-resistant adipocytes and required the epigenetic reader proteins BRD2 and BRD4 in recipient cells. The thrombospondin family protein TSP5, which is associated with cancer, was more abundant in exosomes from T2D or insulin-resistant adipocytes and partially contributed to EMT in recipient cells. Bioinformatic analysis of breast cancer patient tissue showed that greater coexpression of COMP (which encodes TSP5) and BRD2 or BRD3 correlated with poorer prognosis, specifically decreased distant metastasis–free survival. Our findings reveal a mechanism of exosome-mediated cross-talk between metabolically abnormal adipocytes and breast cancer cells that may promote tumor aggressiveness in patients with T2D.

Reduction in unplanned hospitalizations associated with a physician focused intervention to reduce potentially inappropriate medication use among older adults: a population-based cohort study

Background

A multimodal general practitioner-focused intervention in the Local Health Authority (LHA) of Parma, Italy, substantially reduced the prevalence of potentially inappropriate medication (PIM) use among older adults. Our objective was to estimate changes in hospitalization rates associated with the Parma LHA quality improvement initiative that reduced PIM use.

Methods

This population-based longitudinal cohort study was conducted among older residents (> 65 years) using the Parma LHA administrative healthcare database. Crude and adjusted unplanned hospitalization rates were estimated in 3 periods (pre-intervention: 2005–2008, intervention: 2009–2010, post-intervention: 2011–2014). Multivariable negative binomial models estimated trends in quarterly hospitalization rates among individuals at risk during each period using a piecewise linear spline for time, adjusted for time-dependent and time-fixed covariates.

Results

The pre-intervention, intervention, and post-intervention periods included 117,061, 107,347, and 121,871 older adults and had crude hospitalization rates of 146.2 (95% CI: 142.2–150.3), 146.8 (95% CI: 143.6–150.0), and 140.8 (95% CI: 136.9–144.7) per 1000 persons per year, respectively. The adjusted pre-intervention hospitalization rate was declining by 0.7% per quarter (IRR = 0.993; 95% CI: 0.991–0.995). The hospitalization rate declined more than twice as fast during the intervention period (1.8% per quarter, IRR = 0.982; 95% CI: 0.979–0.985) and was nearly constant post-intervention (IRR: 0.999; 95% CI: 0.997–1.001). Contrasting model predictions for the intervention period (Q1 2009 to Q4 2010), the intervention was associated with 1481 avoided hospitalizations.

Conclusion

In a large population of older adults, a multimodal general practitioner-focused intervention to decrease PIM use was associated with a decline in the unplanned hospitalization rate. Such interventions to reduce high risk medication use among older adults warrant consideration by health systems seeking to improve health outcomes and reduce high-cost acute care utilization.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02172-3.

BRD4 regulates key transcription factors that drive epithelial-mesenchymal transition in castration-resistant prostate cancer

BACKGROUND

Androgen deprivation therapies for the hormone-dependent stages of prostate cancer have become so effective that new forms of chemoresistant tumors are emerging in clinical practice, and require new targeted therapies in the metastatic setting. Yet there are important gaps in our understanding of the relevant transcriptional networks driving this process. Progression from localized to metastatic castration resistant prostate cancer (mCRPC) occurs as a result of accumulated resistance mechanisms that develop upon sustained androgen receptor (AR) suppression. Critical to this progression is the plastic nature by which prostate tumor cells transition from epithelial to mesenchymal states (EMT).

METHODS

Here, using prostate cancer cell lines with different AR composition, we systematically manipulated somatic proteins of the Bromodomain and ExtraTerminal (BET) family (BRD2, BRD3, and BRD4) to determine which BET proteins influence EMT. We used the TCGA repository to correlate the expression of individual BET genes with key EMT genes and determined biochemical recurrence in 414 patients and progression free survival in 488 patients.

RESULTS

We found that only BRD4-and not BRD2 or BRD3-regulates the expression of SNAI1 and SNAI2, and that the downregulation of these EMT transcription factors significantly increases E-cadherin expression. Furthermore, of the BET genes, only BRD4 correlates with survival outcomes in prostate cancer patients. Moreover, selective degradation of BRD4 protein with MZ1 ablates EMT (transcriptionally and morphologically) induced by TGFß signaling.

CONCLUSIONS

Many relapsed/refractory tumors share a neuroendocrine transcriptional signature that had been relatively rare until highly successful antiandrogen drugs like abiraterone and enzalutamide came into widespread use. New therapeutic targets must therefore be developed. Our results identify key EMT genes regulated by BRD4, and offers a novel druggable target to treat mCRPC. BRD4-selective protein degraders offer a promising next generation approach to treat the emerging forms of chemoresistance in advanced prostate cancer.

Novel semi-automated algorithm for high-throughput quantification of adipocyte size in breast adipose tissue, with applications for breast cancer microenvironment

The size distribution of adipocytes in fat tissue provides important information about metabolic status and overall health of patients. Histological measurements of biopsied adipose tissue can reveal cardiovascular and/or cancer risks, to complement typical prognosis parameters such as body mass index, hypertension or diabetes. Yet, current methods for adipocyte quantification are problematic and insufficient. Methods such as hand-tracing are tedious and time-consuming, ellipse approximation lacks precision, and fully automated methods have not proven reliable. A semi-automated method fills the gap in goal-directed computational algorithms, specifically for high-throughput adipocyte quantification. Here, we design and develop a tool, AdipoCyze, which incorporates a novel semi-automated tracing algorithm, along with benchmark methods, and use breast histological images from the Komen for the Cure Foundation to assess utility. Speed and precision of the new approach are superior to conventional methods and accuracy is comparable, suggesting a viable option to quantify adipocytes, while increasing user flexibility. This platform is the first to provide multiple methods of quantification in a single tool. Widespread laboratory and clinical use of this program may enhance productivity and performance, and yield insight into patient metabolism, which may help evaluate risks for breast cancer progression in patients with comorbidities of obesity.

ABBREVIATIONS

BMI: body mass index.

Inhibition of Fatty Acid Synthase Upregulates Expression of CD36 to Sustain Proliferation of Colorectal Cancer Cells

Fatty acid synthase, a key enzyme of de novo lipogenesis, is an attractive therapeutic target in cancer. The novel fatty acid synthase inhibitor, TVB-3664, shows anti-cancer activity in multiple cancers including colorectal cancer; however, it is unclear whether uptake of exogeneous fatty acids can compensate for the effect of fatty acid synthase inhibition. This study demonstrates that inhibition of fatty acid synthase selectively upregulates fatty acid translocase (CD36), a fatty acid transporter, in multiple colorectal cancer models including colorectal cancer cells with shRNA mediated knockdown of fatty acid synthase and genetically modified mouse tissues with heterozygous and homozygous deletion of fatty acid synthase. Furthermore, human colorectal cancer tissues treated with TVB-3664 show a significant and selective upregulation of CD36 mRNA. shRNA-mediated knockdown of CD36 and inhibition of CD36 via sulfosuccinimidyl oleate, a chemical inhibitor of CD36, decreased cell proliferation in vitro and reduced tumor growth in subcutaneous xenograft models. Isogenic cell populations established from patient derived xenografts and expressing high levels of CD36 show a significantly increased ability to grow tumors in vivo. The tumor-promoting effect of CD36 is associated with an increase in the levels of pAkt and survivin. Importantly, combinatorial treatment of primary and established colorectal cancer cells with TVB-3664 and sulfosuccinimidyl oleate shows a synergistic effect on cell proliferation. In summary, our study demonstrates that upregulation of CD36 expression is a potential compensatory mechanism for fatty acid synthase inhibition and that inhibition of CD36 can improve the efficacy of fatty acid synthase-targeted therapy.

Cell Cycle Arrest and Apoptosis Induction of Phloroacetophenone Glycosides and Caffeoylquinic Acid Derivatives in Gastric Adenocarcinoma (AGS) Cells

INTRODUCTION

In the present study, we analyzed anti-proliferative and apoptosis induction activity of five phenolic compounds: echisoside, pleoside, chlorogenic acid, 4,5-Di-O-caffeoylquinic acid, and cynarin on AGS (adenocarcinoma gastric) cell line.

METHOD

These phenolic compounds were isolated from methanol extract of Dorema glabrum root. An MTT assay was conducted to evaluate the inhibitory effect on cancer cells. EB/AO staining was done to assess the mode of cell death and morphological changes of the cells' nuclei. Cell cycle distribution of the cells was analyzed by flow cytometry, and for further confirmation of the pathway, mRNA levels of apoptosis cascade players were quantified by qRT-PCR.

RESULT

We found that echisoside, pleoside, chlorogenic acid, 4,5-Di-O-caffeoylquinic acid, and cynarin inhibited the proliferation of AGS cancer cells in vitro. Our data revealed that these compounds triggered morphological changes characteristic of apoptotic cell death. These compounds up-regulated bax and caspase3 expression and down-regulated cyclin D1, bcl2, VEGFA, c-myc and survivin. Moreover, cell population increased at the G1 phase, and a number of cells at the G2/M phase of the cell cycle decreased after treatment.

CONCLUSION

All these data suggest that phenolic compounds have a cytotoxic effect on gastric cancer cells and could trigger apoptosis. Besides cytotoxic activity, they could potentially arrest the cell cycle at the G1 phase.

De Novo Fatty Acid Synthesis-Driven Sphingolipid Metabolism Promotes Metastatic Potential of Colorectal Cancer

Metastasis is the most common cause of death in colorectal cancer patients. Fatty acid synthase (FASN) and sphingosine kinase-1 and -2 (SPHK1 and 2) are overexpressed in many cancers, including colorectal cancer. However, the contribution of FASN-mediated upregulation of sphingolipid metabolism to colorectal cancer metastasis and the potential of these pathways as targets for therapeutic intervention remain unknown. This study determined that sphingosine kinases (SPHK) are overexpressed in colorectal cancer as compared with normal mucosa. FASN expression significantly correlated with SPHK2 expression in data sets from The Cancer Genome Atlas (TCGA) and a colorectal cancer tumor microarray. FASN, SPHK1, and SPHK2 colocalized within invadopodia of primary colorectal cancer cells. Moreover, FASN inhibition decreased SPHK2 expression and the levels of dihydrosphingosine 1-phosphate (DH-S1P) and sphingosine 1-phosphate (S1P) in colorectal cancer cells and tumor tissues. Inhibition of FASN using TVB-3664 and sphingolipid metabolism using FTY-720 significantly inhibited the ability of primary colorectal cancer cells to proliferate, migrate, form focal adhesions, and degrade gelatin. Inhibition of the FASN/SPHK/S1P axis was accompanied by decreased activation of p-MET, p-FAK, and p-PAX. S1P treatment rescued FASN-mediated inhibition of these proteins, suggesting that FASN promotes metastatic properties of colorectal cancer cells, in part, through an increased sphingolipid metabolism. These data demonstrate that upregulation of the FASN/SPHK/S1P axis promotes colorectal cancer progression by enhancing proliferation, adhesion, and migration. IMPLICATIONS: This study provides a strong rationale for further investigation of the interconnection of de novo lipogenesis and sphingolipid metabolism that could potentially lead to the identification of new therapeutic targets and strategies for colorectal cancer.

Cdk5-mediated phosphorylation regulates phosphatidylinositol 4-phosphate 5-kinase type I γ 90 activity and cell invasion

Phosphatidylinositol 4-phosphate 5-kinase type I γ (PIPKIγ90) regulates cell migration, invasion, and metastasis. However, it is unknown how cellular signals regulate those processes. Here, we show that cyclin-dependent kinase 5 (Cdk5), a protein kinase that regulates cell migration and invasion, phosphorylates PIPKIγ90 at S453, and that Cdk5-mediated PIPKIγ90 phosphorylation is essential for cell invasion. Moreover, Cdk5-mediated phosphorylation down-regulates the activity of PIPKIγ90 and the secretion of fibronectin, an extracellular matrix protein that regulates cell migration and invasion. Furthermore, inhibition of PIPKIγ activity with the chemical inhibitor UNC3230 suppresses fibronectin secretion in a dose-dependent manner, whereas depletion of Cdk5 enhances fibronectin secretion. With total internal reflection fluorescence microscopy, we found that secreted fibronectin appears as round dots, which colocalize with Tks5 and CD9 but not with Zyxin. These data suggest that Cdk5-mediated PIPKIγ90 phosphorylation regulates cell invasion by controlling PIPKIγ90 activity and fibronectin secretion.-Li, L., Kołodziej, T., Jafari, N., Chen, J., Zhu, H., Rajfur, Z., Huang, C. Cdk5-mediated phosphorylation regulates phosphatidylinositol 4-phosphate 5-kinase type I γ 90 activity and cell invasion.

Abstract 1437: De novo fatty acid synthesis-driven sphingolipid metabolism promotes metastatic potential of colorectal cancer

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths in the USA. Development of metastasis is the most common cause of death in these patients. Fatty acid synthase (FASN) and Sphingosine Kinases 1 and 2 (SPHK1 and 2) are overexpressed in many cancers, including CRC. However, the contribution of FASN-mediated upregulation of sphingolipid metabolism to CRC metastasis and potential of these pathways as targets for therapeutic intervention remains unknown. The purpose of this study was to determine (i) expression of FASN, SPHK1 and SPHK2 in human CRC tissues, (ii) the effect of upregulation of FASN on sphingolipid metabolism and (iii) functional significance of the FASN/SPHK axis in advanced CRC.

Methods: Expression of FASN, SPHK1 and SPHK2 was assessed in a CRC tumor microarray (matched normal colon and tumor; 56 cases) by immunohistochemistry. Sphingolipids were measured by mass spectrometry. Primary CRC cells were established from CRC patient-derived xenograft (PDX) tumors and treated with TVB-3664, a novel FASN inhibitor, or FTY-720, an S1P mimetic that inhibits SPHKs and S1P receptors. Cellular proliferation was measured using a cell counter. Migration capabilities of cells were assessed by live cell imaging using Nikon BioStation. Invadopodia and focal adhesions were assessed by total internal reflection fluorescence microscopy. Tumor tissues were implanted into 6 to 8-week-old NOD scid gamma mice to establish PDX models. Expression of proteins involved in adhesion, migration and invasion were assessed by western blot.

Results: SPHK1 and SPHK2 were overexpressed in CRC as compared to normal mucosa and expression of FASN correlates with expression of SPHK2 (Spearman's r=0.27894, p=0.0374). Furthermore, FASN and SPHKs co-localized within invadopodia of primary CRC cells. Moreover, FASN inhibition decreased expression of SPHK2 and the level of Sphingosine-1-phosphate (S1P) in primary and established CRC cells. Inhibition of de novo lipogenesis using TVB-3664 or FTY-720 significantly inhibited proliferation, migration, focal adhesion formation and gelatin degradation ability of primary CRC cells. Inhibition of the FASN/SPHK/S1P axis was accompanied by a decrease in activation of p-MET, p-FAK, and p-Paxilin in vitro and in vivo. S1P treatment rescued FASN-mediated inhibition of these proteins suggesting that FASN promotes metastatic properties of CRC cells, in part, through an increase in sphingolipid metabolism.

Conclusion: Upregulation of the FASN/SPHK/S1P axis promotes CRC progression by enhancing cellular proliferation, adhesion and migration. Therefore, this study provides a strong rationale for further investigation of the interconnection of de novo lipogenesis and sphingolipid metabolism that would potentially lead to identification of new therapeutic targets and strategies for CRC.

Citation Format: Naser Jafari, James Drury, Andrew J. Morris, Fredrick O. Onono, Payton D. Stevens, Tianyan Gao, Eun Y. Lee, Heidi L. Weiss, B Mark Evers, Yekaterina Zaytseva. De novo fatty acid synthesis-driven sphingolipid metabolism promotes metastatic potential of colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1437.

Abstract 1443: Overexpression of CD36 promotes tumorigenesis in colorectal cancer

Fatty acid translocase (CD36), a multifunctional glycoprotein, has an important role in fatty acid metabolism as a fatty acid receptor and transporter. The presence of CD36 positive metastasis-initiating cells correlates with a poorer prognosis in glioblastoma and oral carcinoma. Fatty acid synthase (FASN), a critical enzyme involved in de novo lipogenesis, is upregulated and associated with poorer prognosis in many cancers including colorectal cancer (CRC). The role of CD36 in primary and metastatic CRC as well as its relation to de novo fatty acid synthesis is not understood. The purpose of our study was: (i) to determine the role of CD36 in primary and metastatic CRC, and (ii) to delineate the association of CD36 expression with FASN as a possible mechanism of resistance to FASN inhibition.

METHODS. Expression of CD36 and FASN was assessed in a CRC tumor microarray (matched normal colon and primary tumor; 56 cases) as well as matched normal colon, primary and metastatic tumors (liver [n=12] and lung metastasis [n=5]) by immunohistochemistry. CD36 expression was analyzed in control and FASN shRNA knockout CRC cells and tissues from APC/FASN/CRE mouse models by western blot. Cell proliferation was assessed in primary CRC cells established from patient derived xenografts (PDX) treated in combination with Sulfo-N-succinimidyl oleate (SSO), an irreversible inhibitor of CD36, and FASN inhibitor TVB-3664. CD36 expression levels in primary and metastatic PDX derived CRC cells were analyzed via western blot and immunofluorescence imaging.

RESULTS. CD36 is overexpressed in primary tumors as compared to normal colon mucosa and its expression positively correlates with expression of FASN. Cell proliferation was significantly reduced when CD36 was inhibited by SSO and a further reduction in cell proliferation was observed when SSO treatment was combined with TVB-3664. Treatment with SSO induced apoptotic markers such as cleaved capspase-3 and decreased survivin. Western blot analysis of primary and metastatic CRC cells showed an upregulation of CD36 expression in the metastatic CRC cells. Additionally, FASN shRNA knockdown of FASN in CRC cells and Cre recombinase-mediated intestinal deletion of FASN in an APC/FASN/CRE mouse model led to an induction of CD36 expression. Immunofluorescence imaging of primary CRC treated with TVB-3664 showed an upregulation of membrane bound CD36.

CONCLUSION. CD36 upregulation is associated with CRC progression and inhibition of CD36 decreases proliferation and survival of primary CRC cells. Correlation between expression of CD36 and FASN suggests an interconnection between CD36 and de novo lipid synthesis. Furthermore, a decrease in FASN expression is associated with an induction of CD36, suggesting a possible mechanism of resistance to FASN inhibition. Better understanding the role of CD36 may provide new therapeutic approaches for treatment of CRC patients.

Citation Format: James M. Drury, Naser Jafari, B Mark Evers, Yekaterina Y. Zaytseva. Overexpression of CD36 promotes tumorigenesis in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1443.

Effect of magnesium on arrhythmia incidence in patients undergoing coronary artery bypass grafting

BACKGROUND

Cardiac arrhythmia after coronary artery bypass grafting (CABG) surgery is a common complication of cardiac surgery. The effect of serum magnesium, hypomagnesaemia treatment and prophylactic administration of magnesium in the development and prevention of arrhythmias is controversial and there are many different ideas. This study evaluates the therapeutic effects of magnesium in cardiac arrhythmia after CABG surgery.

METHODS

The clinical trial enrolled 250 patients who underwent CABG. Based on the initial serum levels of magnesium, patients were divided into two groups: hypomagnesium and normomagnesium. Based on bioethics committee requirements, patients in the hypo-magnesium group received magnesium treatments until they attained normal magnesium blood levels. Both groups underwent CABG with normal blood levels of magnesium. After surgery, each group was randomly divided into two subgroups: one subgroup received a bolus dose of magnesium sulphate (30 mg/kg in 5 min) and the other subgroup received a placebo. Subgroups were under observation in the intensive care unit for 3 days and arrhythmias were recorded. Data from all four subgroups were analysed statistically and interpreted.

RESULTS

The results of this study showed that the occurrence of arrhythmia was not significantly different among subgroups (P > 0.05). There was no significant relationship between blood levels of magnesium and arrhythmia during the 3 days post-surgery (P > 0.05).

CONCLUSION

The results of this study showed that magnesium sulphate administration did not significantly improve the incidence of arrhythmias in hypo- and normo-magnesium patients after CABG. There was no significant correlation between post-operative serum levels of magnesium and arrhythmia during 3 days.

The role of talin2 in breast cancer tumorigenesis and metastasis

Recent studies show that talin2 has a higher affinity to β-integrin tails and is indispensable for traction force generation and cell invasion. However, its roles in cell migration, cancer cell metastasis and tumorigenesis remain to be determined. Here, we used MDA-MB-231 human breast cancer cells as a model to define the roles of talin2 in cell migration, invasion, metastasis and tumorigenesis. We show here that talin2 knockdown (KD) inhibited cell migration and focal adhesion dynamics, a key step in cell migration, and that talin2 knockout (KO) inhibited cell invasion and traction force generation, the latter is crucial for cell invasion. Re-expression of talin2^WT in talin2-KO cells restored traction force generation and cell invasion, but that of talin2^S339C, a β-integrin-binding deficient mutant, did not. Moreover, talin2 KO (or KD) suppressed tumorigenesis and metastasis in mouse xenograft models. However, surprisingly, re-expression of talin2^WT in talin2-KO cells did not rescue tumorigenesis. Thus, talin2 is required for breast cancer cell migration, invasion, metastasis and tumorigenesis, although exogenous expression of high levels of talin2 could inhibit tumorigenesis.

Talin2-mediated traction force drives matrix degradation and cell invasion

Talin binds to β-integrin tails to activate integrins, regulating cell migration, invasion and metastasis. There are two talin genes, TLN1 and TLN2, encoding talin1 and talin2, respectively. Talin1 regulates focal adhesion dynamics, cell migration and invasion, whereas the biological function of talin2 is not clear and, indeed, talin2 has been presumed to function redundantly with talin1. Here, we show that talin2 has a much stronger binding to β-integrin tails than talin1. Replacement of talin2 Ser339 with Cys significantly decreased its binding to β1-integrin tails to a level comparable to that of talin1. Talin2 localizes at invadopodia and is indispensable for the generation of traction force and invadopodium-mediated matrix degradation. Ablation of talin2 suppressed traction force generation and invadopodia formation, which were restored by re-expressing talin2 but not talin1. Furthermore, re-expression of wild-type talin2 (but not talin2^S339C) in talin2-depleted cells rescued development of traction force and invadopodia. These results suggest that a strong interaction of talin2 with integrins is required to generate traction, which in turn drives invadopodium-mediated matrix degradation, which is key to cancer cell invasion.

The effect of boron dilution transient on the VVER-1000 reactor core using MCNP and COBRA-EN codes

In this paper, the effect of boron dilution transient, as a consequence of the malfunction of the boron control system, was investigated in a VVER-1000 reactor, and then an appropriate setpoint was determined for the actuation of the emergency protection system to the reactor shutdown. In order to simulate the boron dilution, first, the whole reactor core was simulated by MCNPX code to compute the radial and axial power distribution. Then, the COBRA-EN code was employed using calculated power distribution for analyzing the thermal-hydraulic of hot fuel assembly and for extracting the safety parameters. For the safe operation of the reactor, certain parameters must be in defined specified ranges. Comparison between our results and FSARs data shows that the present modeling provides a good prediction of boron dilution transient with the maximum relative difference about 4%.

Potent anti-cancer effects of less polar Curcumin analogues on gastric adenocarcinoma and esophageal squamous cell carcinoma cells

Curcumin and its chalcone derivatives inhibit the growth of human cancer cells. It is reported that replacement of two OH groups in curcumin with less polar groups like methoxy increases its anti-proliferative activity. In this study, we explored benzylidine cyclohexanone derivatives with non-polar groups, to see if they possess increased anti-cancer activity. Novel 2,6-bis benzylidine cyclohexanone analogues of curcumin were synthesized, and their inhibitory effects on gastric adenocarcinoma (AGS) and esophageal squamous cell carcinoma (KYSE30) cancer cells were studied using an MTT assay. Cell apoptosis was detected by EB/AO staining, and cell cycle was analyzed by flow cytometry. Real-time PCR was performed for gene expression analysis. All synthesized analogues were cytotoxic toward gastric and esophageal cancer cells and showed lower IC₅₀ values than curcumin. Treatment with 2,6-Bis-(3-methoxy-4-propoxy-benzylidene)-cyclohexanone (BM2) was 17 times more toxic than curcumin after 48 h incubation. All novel compounds were more effective than curcumin in apoptosis induction and cell cycle arrest at G1 phase. These results suggest that less polar analogues of curcumin have potent cytotoxicity in vitro. However, they need to be investigated further, especially with animal tumor models, to confirm their chemotherapeutic activity in vivo.

Induction of Apoptosis and Cell Cycle Arrest by Dorema Glabrum Root Extracts in a Gastric Adenocarcinoma (AGS) Cell Line

Objective:

Dorema glabrum Fisch. & C.A. Mey is a perennial plant that has several curative properties. Anti-proliferative activity of seeds of this plant has been demonstrated in a mouse fibrosarcoma cell line. The aim of the present study was to evaluate cytotoxicity of D. glabrum root extracts in a human gastric adenocarcinoma (AGS) cell line and explore mechanisms of apoptosis induction, cell cycle arrest and altered gene expression in cancer cells.

Materials and Methods:

The MTT assay was used to evaluate IC50 values, EB/AO staining to analyze the mode of cell death, and flow cytometry to assess the cell cycle. Quantitative real-time polymerase chain reaction (qRT-PCR) amplification was performed with apoptosis and cell cycle-related gene primers, for cyclin D1, c-myc, survivin, VEGF, Bcl-2, Bax, and caspase-3 to determine alteration of gene expression.

Results:

Our results showed that n-hexane and chloroform extracts had greatest toxic effects on gastric cancer cells with IC50 values of 6.4 µg/ml and 4.6 µg/ml, respectively, after 72 h. Cell cycle analysis revealed that the population of treated cells in the G1 phase was increased in comparison to controls. Cellular morphological changes indicated induction of apoptosis. In addition, mRNA expression levels of Bax and caspase-3 were increased, and of bcl-2 survivin, VEGF, c-myc and cyclin D1 were decreased.

Conclusion:

Our study results suggest that D. glabrum has cytotoxic effects on AGS cells, characterized by enhanced apoptosis, reduced cell viability and arrest of cell cycling.

p70S6K1 (S6K1)-mediated Phosphorylation Regulates Phosphatidylinositol 4-Phosphate 5-Kinase Type I γ Degradation and Cell Invasion

Phosphatidylinositol 4-phosphate 5-kinase type I γ (PIPKIγ90) ubiquitination and subsequent degradation regulate focal adhesion assembly, cell migration, and invasion. However, it is unknown how upstream signals control PIPKIγ90 ubiquitination or degradation. Here we show that p70S6K1 (S6K1), a downstream target of mechanistic target of rapamycin (mTOR), phosphorylates PIPKIγ90 at Thr-553 and Ser-555 and that S6K1-mediated PIPKIγ90 phosphorylation is essential for cell migration and invasion. Moreover, PIPKIγ90 phosphorylation is required for the development of focal adhesions and invadopodia, key machineries for cell migration and invasion. Surprisingly, substitution of Thr-553 and Ser-555 with Ala promoted PIPKIγ90 ubiquitination but enhanced the stability of PIPKIγ90, and depletion of S6K1 also enhanced the stability of PIPKIγ90, indicating that PIPKIγ90 ubiquitination alone is insufficient for its degradation. These data suggest that S6K1-mediated PIPKIγ90 phosphorylation regulates cell migration and invasion by controlling PIPKIγ90 degradation.