Correction: Hamilton et al. Receptors for Insulin-Like Growth Factor-2 and Androgens as Therapeutic Targets in Triple-Negative Breast Cancer. Int. J. Mol. Sci. 2017, 18, 2305

In the original publication [...].

Advancements in small molecule drug design: A structural perspective

In this review, we outline recent advancements in small molecule drug design from a structural perspective. We compare protein structure prediction methods and explore the role of the ligand binding pocket in structure-based drug design. We examine various structural features used to optimize drug candidates, including functional groups, stereochemistry, and molecular weight. Computational tools such as molecular docking and virtual screening are discussed for predicting and optimizing drug candidate structures. We present examples of drug candidates designed based on their molecular structure and discuss future directions in the field. By effectively integrating structural information with other valuable data sources, we can improve the drug discovery process, leading to the identification of novel therapeutics with improved efficacy, specificity, and safety profiles.

From Interaction to Intervention: How Mesenchymal Stem Cells Affect and Target Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) lacks estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 expressions, making targeted therapies ineffective. Mesenchymal stem cells (MSCs) have emerged as a promising approach for TNBC treatment by modulating the tumor microenvironment (TME) and interacting with cancer cells. This review aims to comprehensively overview the role of MSCs in TNBC treatment, including their mechanisms of action and application strategies. We analyze the interactions between MSC and TNBC cells, including the impact of MSCs on TNBC cell proliferation, migration, invasion, metastasis, angiogenesis, and drug resistance, along with the signaling pathways and molecular mechanisms involved. We also explore the impact of MSCs on other components of the TME, such as immune and stromal cells, and the underlying mechanisms. The review discusses the application strategies of MSCs in TNBC treatment, including their use as cell or drug carriers and the advantages and limitations of different types and sources of MSCs in terms of safety and efficacy. Finally, we discuss the challenges and prospects of MSCs in TNBC treatment and propose potential solutions or improvement methods. Overall, this review provides valuable insights into the potential of MSCs as a novel therapeutic approach for TNBC treatment.

RF19 | PSUN344 Control of Androgen Signaling and Metastasis by CARF in Prostate Cancer

Background

Prostate cancer (PCa) is a leading cause of cancer-associated death among men worldwide. Although localized prostate cancer can be cured by surgery and radiation therapy, metastatic PCa remains a challenge. Androgen therapy (ADT) and androgen signaling inhibitors are the first line of therapy against PCa. However, resistance against these treatments develops, leading to the emergence of castration resistance prostate cancer (CRPC). Studies are required to identify the pathways that contribute to the emergence of CRPC and identify pharmaceutical targets. CARF is a putative transcription regulator reported to play a pivotal role in different cancers, including breast cancer and hepatocarcinoma. We observed that CARF is highly expressed in prostate tumors, but the biological function of CARF in PCa is unknown yet.

Methods

We performed RNA seq, RT-PCR, and western blot (WB) analyses to show how knockdown of CARF affects the global gene expression in PC3 cells. Gene sort enrichment analysis (GSEA) and Ingenuity Pathway Analysis (IPA) of differentially expressed genes were done to identify the cellular pathways affected upon silencing of CARF. Scratch assay and trans-well migration assay were conducted to show how CARF overexpression influences the motility of the cells. The effect of CARF on PC3 cells growth and proliferation was evaluated by colony-forming and MTT assays. In addition, we analyzed patient datasets to show the relevance of CARF expression, androgen signaling, and epithelial-mesenchymal transformation (EMT) pathways in PCa.

Results

The silencing of CARF inhibited the growth and proliferation of PC3 cells, suggesting the necessity of CARF for PC3 growth and survival. In agreement, overexpression of CARF enhanced the PC3 cells proliferation. We found that silencing of CARF reduced PC3 cells motility in trans-well assay. Mechanistically, RNA seq analysis after CARF knockdown uncovered that gene of AR signaling and EMT pathways were significantly altered in PC3 cells. RT-PCR and WB data confirmed that silencing of CARF enhanced E-cadherin expression and reduced the expression of N-cadherin in PC3 cells, suggesting that CARF regulates EMT in PCa. Silencing of CARF altered the AR-regulated metastatic genes expression in PC3 cells. Our data revealed that the expression of PMEPA1, a negative regulator of metastasis, was increased, but the expression of SGK1, an inducer of EMT, was decreased in CARF cells. Furthermore, CARF could regulate the prostaglandins metabolism by suppressing the expression of HGPD1 and triggering inflammation and angiogenesis in prostate cancer.

Conclusion

We conclude that by controlling the AR and EMT signaling pathways, CARF may play a crucial role in the development of metastatic CRPC. Future studies by integrating the RNA seq and Chip-Seq will uncover how CARF regulates the AR and EMT signaling pathways contributing to the development and progression of CRPC and paving a way to find a target for intervention.

Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m., Sunday, June 12, 2022 1:18 p.m. - 1:23 p.m.

Abstract 943: Insulin-like growth factor-2 a potential target for screening and treatment in patients with triple negative breast cancer

Triple-negative breast cancer (TNBC) affects only about 10-15% of women with breast cancer (BC) but accounts for almost 50% of all BC deaths. At this time, development of targeted treatments for TNBC are urgently needed. Insulin-like growth factor-2 (IGF2) is highly expressed in TNBCs and mediates its proliferative effects via two hormone receptors, insulin-like growth factor -1 receptor (IGF1R) and insulin receptor (IR). Using a TNBC tissue microarray (TMA) consisting of 159 archival clinical samples, we confirm that IGF2 is highly expressed in tumor tissue as compared to nearby normal tissue (P<0.001). In addition, evaluation of a second breast cancer TMA that included archival TNBC samples from African American and Latino women, IGF2 expression was similarly higher in these samples than in samples from Caucasian women (P<0.02). Since enrichment of IGF1R and IR are detected in TNBC and are known to allow signaling crosstalk, the effects of BMS-754807, a dual IGF1R/IR antagonist, were assessed on TNBC progression in vitro and in vivo with human and murine models. To determine the effects of BMS-754807 in vitro, we used cell viability assays with TNBC cell lines, MDA-MB-231 and HCC1806. BMS-754807 significantly reduced cell viability after 48 and 72 hours (P< 0.01), and a similar effect was observed in the murine TNBC cell line 4T1 (P< 0.01). In vivo, BMS-754807 inhibited tumor growth of human TNBC as well as mouse 4T1 xenografts (P< 0.05). Further, in studies of immune cell populations using syngeneic 4T1 tumor xenografts, BMS-754807 significantly decreased myeloid derived suppressor cells (P <0.05) in the tumor microenvironment (TME) and in the spleen of BALC/c mice. Additionally, there was an increase in T effector CD8+ and CD4+ tumor infiltrating lymphocytes (P< 0.05), particularly of spleen T central memory cells (P<0.01). Notably, conversion of CD8+ from T central memory to a T effector memory phenotype that is fully active against tumors can confer long term immunity against recurrence. This data suggest that IGF2 is a potential biological marker for breast cancer disparities and that targeting receptors of IGF2 with drugs such as BMS-754807 could provide additional treatment options in combination with current therapies, thus reducing TNBC progression and ultimately improving patient outcomes. [Funded by NIH U54 143931 Cancer Center Partnership and CBCRP]

Citation Format: Nalo M. Hamilton, Diana Marquez-Garban, David Austin, Neda Moatamed, Lorena P. Burton, David Elashoff, Begonya Comin-Anduix, Tristan Grogan, Madhuri Wadehra, Helena Chang, Adrienne Martinez, Mary-Lynn Brecht, Isabel Jabara, Richard Pietras, Yahya Elshimali, Jaydutt Vadgama, Michael Jung. Insulin-like growth factor-2 a potential target for screening and treatment in patients with triple negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 943.

Basal-like breast cancer with low TGFβ and high TNFα pathway activity is rich in activated memory CD4 T cells and has a good prognosis

Basal-like breast cancer (BLBC) is a type of high-grade invasive breast cancer with high risk of recurrence, metastases, and poor survival. Immune activation in BLBC is a key factor that influences both cancer progression and therapeutic response, although its molecular mechanisms are not well clarified. In this study, we examined five cancer immunity-related pathways (IFNα, IFNγ, STAT3, TGFβ and TNFα) in four large independent breast cancer cohorts (n = 6,381) and their associations with the prognosis of breast cancer subtypes. Activities of the 5 pathways were calculated based on corresponding pathway signatures and associations between pathways and clinical outcomes were examined by survival analysis. Among the five PAM50-based subtypes, BLBC had the highest IFNα, IFNγ, TNFα pathway activities, and the lowest TGFβ activity. The IFNα, IFNγ, TNFα pathway activities were negatively correlated with BLBC recurrence. In contrast, positive association and no association with BLBC recurrence were observed for TGFβ and STAT3 pathways, respectively. TNFα/TGFβ pathway combination improved the prediction of recurrence and chemotherapy response of BLBCs. Immune cell subset analysis in BLBC showed that M0, M1 and M2 macrophage levels were associated with either TNFα or TGFβ pathways, whereas the level of activated memory CD4 T cells were associated with both pathways. Moreover, this T cell subset was most abundant in BLBCs with low TGFβ and high TNFα pathway activities. These results suggested that cooperation of TNFα and TGFβ signaling may be involved in the regulation of memory T cells and anti-cancer immunity in BLBCs. Our data also demonstrate that TNFα/TGFβ pathway combination may represent a better biomarker for BLBC prognosis and clinical management.

Wild-Type TP53 Predicts Poor Prognosis in Patients with Gastric Cancer

TP53 gene is often mutated in gastric cancer (GC), nonetheless its relationship with clinicopathological characteristics and prognosis is still unclear. Here, we sought to ascertain the difference in clinical phenotypes between TP53 wild-type and mutant tumors in confirmed gastric cancer patients. To this end, we analyzed TP53 mutation status of 415 TCGA GC patients in relation to their clinical and pathological features as well as prognosis. Longrank Test showed that the survival rate of gastric cancer patients with TP53 WT was significantly lower than that of TP53 mut. Compared with TP53 mut gastric cancer patients with low mRNA expression, TP53 WT patients with low mRNA expression have lower overall survival rate. The death risk of TP53 WT gastric cancer patients is 1.395 times that of TP53 mut gastric cancer patients. The death risk of TP53 mut gastric cancer patients is not related to age, and advanced age is not a risk factor. However, the death risk of TP53 WT patients with gastric cancer increases with age, and the death risk of patients over 70 years old is 1.899 times that of patients under 60 years old. These results suggest that the prognosis of elderly gastric cancer patients with TP53 WT is worse.

Nicotine Synergizes with High-Fat Diet to Induce an Anti-Inflammatory Microenvironment to Promote Breast Tumor Growth

Breast cancer results from a complex interplay of genetics and environment that alters immune and inflammatory systems to promote tumorigenesis. Obesity and cigarette smoking are well-known risk factors associated breast cancer development. Nicotine known to decrease inflammatory signals also modulates immune responses that favor breast cancer development. However, the mechanisms by which nicotine and obesity contribute to breast cancer remain poorly understood. In this study, we examined potential mechanisms by which nicotine (NIC) and high-fat diet (HFD) promote growth of HCC70 and HCC1806 xenografts from African American (AA) triple negative (TN) breast cancer cells. Immunodeficient mice fed on HFD and treated with NIC generated larger HCC70 and HCC1806 tumors when compared to NIC or HFD alone. Increased xenograft growth in the presence of NIC and HFD was accompanied by higher levels of tissue-resident macrophage markers and anti-inflammatory cytokines including IL4, IL13, and IL10. We further validated the involvement of these players by in vitro and ex vivo experiments. We found a proinflammatory milieu with increased expression of IL6 and IL12 in xenografts with HFD. In addition, nicotine or nicotine plus HFD increased a subset of mammary cancer stem cells (MCSCs) and key adipose browning markers CD137 and TMEM26. Interestingly, there was upregulation of stress-induced pp38 MAPK and pERK1/2 in xenografts exposed to HFD alone or nicotine plus HFD. Scratch-wound assay showed marked reduction in proliferation/migration of nicotine and palmitate-treated breast cancer cells with mecamylamine (MEC), a nicotine acetylcholine receptor (nAchR) antagonist. Furthermore, xenograft development in immune-deficient mice, fed HFD plus nicotine, was reduced upon cotreatment with MEC and SB 203580, a pp38MAPK inhibitor. Our study demonstrates the presence of nicotine and HFD in facilitating an anti-inflammatory tumor microenvironment that influences breast tumor growth. This study also shows potential efficacy of combination therapy in obese breast cancer patients who smoke.

A novel curcumin analog inhibits canonical and non-canonical functions of telomerase through STAT3 and NF-κB inactivation in colorectal cancer cells

Curcumin is a biologically active polyphenol that exists in Indian spice turmeric. It has been reported that curcumin exerted anti-inflammatory, anti-oxidant and anti-cancer effects in numerous in vitro and in vivo studies. However, it is not well-understood the molecular mechanism of curcumin for the cancer stem cells and telomerase in colorectal cancer. In this study, compound 19, a nitrogen-containing curcumin analog, was used to treat human colorectal cancer cells. Compound 19 showed a greater anti-proliferative activity than curcumin while displayed no significant toxicity toward normal human colon epithelial cells. Compound 19 exerted anti-inflammatory activities by deactivating STAT3 and NF-κB. In cancer stem cell populations, CD44, Oct-4 and ALDHA1 expressions were abolished upon treating with compound 19. Cancer stem cell biomarkers CD51 and CD133 positive populations were reduced and telomerase activities were decreased with the reduced STAT3 binding to hTERT promoters. This means compound 19 dually inhibits canonical and non-canonical functions of telomerase. Furthermore, compound 19 treatments induced cell cycle arrest at G1 phase and apoptosis. Human apoptosis-related array screening revealed that activated caspase 3, catalase, clusterin and cytochrome C led to apoptosis. Taken together, our data suggest that compound 19 can be a novel therapeutic agent for metastatic colorectal cancer by concurrently targeting STAT3 and NF-κB signaling pathways.

The Research Centers in Minority Institutions (RCMI) Translational Research Network: Building and Sustaining Capacity for Multi-Site Basic Biomedical, Clinical and Behavioral Research

The Research Centers in Minority Institutions (RCMI) program was established by the US Congress to support the development of biomedical research infrastructure at minority-serving institutions granting doctoral degrees in the health professions or in a health-related science. RCMI institutions also conduct research on diseases that disproportionately affect racial and ethnic minorities (ie, African Americans/Blacks, American Indians and Alaska Natives, Hispanics, Native Hawaiians and Other Pacific Islanders), those of low socioeconomic status, and rural persons. Quantitative metrics, including the numbers of doctoral science degrees granted to underrepresented students, NIH peer-reviewed research funding, peer-reviewed publications, and numbers of racial and ethnic minorities participating in sponsored research, demonstrate that RCMI grantee institutions have made substantial progress toward the intent of the Congressional legislation, as well as the NIH/NIMHD-linked goals of addressing workforce diversity and health disparities. Despite this progress, nationally, many challenges remain, including persistent disparities in research and career development awards to minority investigators. The continuing underrepresentation of minority investigators in NIH-sponsored research across multiple disease areas is of concern, in the face of unrelenting national health inequities. With the collaborative network support by the RCMI Translational Research Network (RTRN), the RCMI community is uniquely positioned to address these challenges through its community engagement and strategic partnerships with non-RCMI institutions. Funding agencies can play an important role by incentivizing such collaborations, and incorporating metrics for research funding that address underrepresented populations, workforce diversity and health equity.

Abstract B55: Tumor-derived MCP-1 regulates invasiveness in triple-negative breast cancer via the MAP kinase pathway

Background: Triple-negative breast cancer (TNBC) is the most aggressive type of breast cancer compared to other breast cancer subtypes. The frequency of TNBC expression is highest in young African-American women, leading to significant cancer health disparity in this population. Furthermore, TNBC is difficult to treat due to lack of known receptor targets at protein or gene level. Hence, it is imperative to identify novel therapeutic strategies for treatment of TNBC. Here we aim to show that the Monocyte Chemoattractant Protein -1 (MCP-1) is a reliable biochemical marker to assess TNBC progression.

Experimental Design: We employed ELISA method to measure secreted MCP-1 in cell conditioned media, and real-time PCR to determine the mRNA status of MCP-1 in different TNBC cell lines. Boyden chamber assay was used to determine the effect of recombinant MCP-1 on cellular invasiveness. Immunohistochemistry staining was utilized for detecting protein of interest in tissue samples from breast cancer patients. MCP-1 knockdown was performed using lentiviral vector with shRNA targeting MCP-1 coding regions. RNAseq was performed with recombinant human MCP-1.

Results: Our data show that MCP-1 is upregulated in TNBC cell lines, both transcriptionally and in secreted protein levels compared to ER-positive cell line, MCF-7. Breast cancer patients also showed high expression of MCP-1. MCP-1 treatment induced MDA-MB-231 and MCF-7 cell invasion, without affecting cell proliferation. Small-molecule antagonists against chemokine receptor 2 (CCR2), cognate receptor for MCP-1, and the MAP kinase pathway inhibitor U0106 negatively affected MDA-MB-231 cell invasion as measured by the Boyden chamber assay. This suggests that MCP-1-CCR2 axis may regulate invasiveness via the MAP kinase pathway. Knocking down MCP-1 by shRNA decreased cell invasion in TNBC cell line, BT-549, along with downregulation of key epithelial-to-mesenchymal transition markers, N-cadherin and Vimentin. Recombinant MCP-1 treatment in TNBC MDA-MB-231 cells upregulated genes associated with cytokine signaling.

Conclusion: Our study suggests that a high MCP-1 level in TNBC cells may be responsible for increase in cell invasion via the MAP kinase pathway. Thus, MCP-1-mediated pathways could be potential therapeutic targets for the treatment of TNBC and reduce cancer health disparities.

Citation Format: Pranabananda Dutta, Kimberly Paico, Yanyuan Wu, Marianna Sarkissyan, Jaydutt Vadgama. Tumor-derived MCP-1 regulates invasiveness in triple-negative breast cancer via the MAP kinase pathway [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr B55.

Estrogen Receptor-β and the Insulin-Like Growth Factor Axis as Potential Therapeutic Targets for Triple-Negative Breast Cancer

Triple-negative breast cancers (TNBCs) lack estrogen receptor-α (ERα), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER2) amplification and account for almost half of all breast cancer deaths. This breast cancer subtype largely affects women who are premenopausal, African-American, or have BRCA1/2 mutations. Women with TNBC are plagued with higher rates of distant metastasis that significantly diminish their overall survival and quality of life. Due to their poor response to chemotherapy, patients with TNBC would significantly benefit from development of new targeted therapeutics. Research suggests that the insulin-like growth factor (IGF) family and estrogen receptor beta-1 (ERβ1), due to their roles in metabolism and cellular regulation, might be attractive targets to pursue for TNBC management. Here, we review the current state of the science addressing the roles of ERβ1 and the IGF family in TNBC. Further, the potential benefit of metformin treatment in patients with TNBC as well as areas of therapeutic potential in the IGF-ERβ1 pathway are highlighted.

Receptors for Insulin-Like Growth Factor-2 and Androgens as Therapeutic Targets in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) occurs in 10-15% of all breast cancer patients, yet it accounts for about half of all breast cancer deaths. There is an urgent need to identify new antitumor targets to provide additional treatment options for patients afflicted with this aggressive disease. Preclinical evidence suggests a critical role for insulin-like growth factor-2 (IGF2) and androgen receptor (AR) in regulating TNBC progression. To advance this work, a panel of TNBC cell lines was investigated with all cell lines showing significant expression of IGF2. Treatment with IGF2 stimulated cell proliferation in vitro (p < 0.05). Importantly, combination treatments with IGF1R inhibitors BMS-754807 and NVP-AEW541 elicited significant inhibition of TNBC cell proliferation (p < 0.001). Based on Annexin-V binding assays, BMS-754807, NVP-AEW541 and enzalutamide induced TNBC cell death (p < 0.005). Additionally, combination of enzalutamide with BMS-754807 or NVP-AEW541 exerted significant reductions in TNBC proliferation even in cells with low AR expression (p < 0.001). Notably, NVP-AEW541 and BMS-754807 reduced AR levels in BT549 TNBC cells. These results provide evidence that IGF2 promotes TNBC cell viability and proliferation, while inhibition of IGF1R/IR and AR pathways contribute to blockade of TNBC proliferation and promotion of apoptosis in vitro.

Abstract 5253: Arctigenin inhibits prostate tumor growth in vitro and in vivo in obese state

Arctigenin is a novel anti-inflammatory lignan derived mainly from the seeds of Arctium lappa which is an herb widely used in traditional Chinese medicine to treat inflammation related diseases. We previously demonstrated that arctigenin strongly inhibited prostate tumor cell growth in cell culture and mouse models in non-obese state. The present study investigated the tumor inhibitory effect of arctigenin in obese state. An in vitro obese setting was created by co-culture of mouse adipocytes 3T3-L1 with androgen-sensitive LAPC-4 and LNCaP prostate cancer cells. An ELISA analysis of 3T3-L1 conditioned medium revealed that three cytokines/growth factors were prominently secreted by 3T3-L1 cells, including IGF-1, VEGF, and MCP-1, and the sensitivity of prostate cancer cells to arctigenin was decreased in the obese state. However, arctigenin at a moderate concentration (10 µM) significantly inhibited the proliferation of both LAPC-4 and LNCaP cell by 40-50% at 96h in the co-culture system. Male severe combined immunodeficiency (SCID) mice was implanted subcutaneously with LAPC-4 xenograft tumors to confirm the tumor-inhibitory effect of arctigenin in vivo. Mice were fed high-fat diet containing 45% energy from fat, and treated with arctigenin at 50mg/kg b.w. orally or vehicle control for 6 weeks (n=10 per group). The tumor growth in arctigenin group was significantly inhibited by 40% compared to control, along with decreased blood concentrations of several cytokines including IGF-1, VEGF, and MCP-1. Immunohistochemistry analysis is ongoing to determine the molecular changes involved in tumor cell proliferation and apoptosis in response to arctigenin treatment. This study provides a promising natural compound to enhance chemoprevention of prostate cancer especially in obese patients. These results warrant future clinical trial studies to confirm the anti-carcinogenic effect of arctigenin in humans.

Citation Format: Piwen Wang, Tanya Diaz, Susanne Henning, Jaydutt Vadgama. Arctigenin inhibits prostate tumor growth in vitro and in vivo in obese state [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5253. doi:10.1158/1538-7445.AM2017-5253

Abstract 1960: Upregulation of MCP-1 regulates invasiveness in triple negative breast cancer

Background: Triple negative breast cancer (TNBC) poses a critical problem for targeted therapy due to lack of significant expression of estrogen, progesterone receptor or Her2/neu oncogene. Hence, it is imperative to identify novel therapeutic strategies to target TNBC. Our study is aimed to examine whether Monocyte Chemoattractant Protein -1 (MCP-1) is a specific marker for TNBC metastasis. Experimental

Design: We employed ELISA to determine secreted MCP-1 in cell conditioned media, as well as Real-time PCR to determine the status of MCP-1 in TNBC cell lines. Boyden chamber assay was used to determine the effect of recombinant MCP-1 on cellular metastasis. Cellular proliferation was measured with MTT assay. Immunofluorescence staining was utilized for protein of interest in breast cancer cells. MCP-1 knockdown was performed using lentiviral vector with shRNA targeting MCP-1 coding regions.

Results: Our data show that the key inflammatory chemokine MCP-1 is upregulated in TNBC cell lines both transcriptionally as well as in terms of secretion compared to ER-positive cell line, MCF-7. MCP-1 stimulation in MDA-MB231 and MCF-7cells does not affect cellular proliferation. However, MCP-1 enhances metastatic properties of MDA-MB-231 cells along with BT-549 cells. Inhibiting Chemokine receptor 2/4 (CCR2/4), cognate receptor for MCP-1, with small molecule antagonists negatively affects invasiveness in MDA-MB-231 cells as evidenced by Boyden chamber assay. Knocking down MCP-1 by shRNA decreases cell invasion in TNBC cell line, BT-549 along with downregulation of key epithelial to mesenchymal transition markers, N-cadherin and Vimentin. MCP-1 induced cell invasion in TNBC may involve activation of p44/p42 MAPK Thr202/Tyr204.

Conclusion: Our study suggests that high MCP-1 levels in TNBC is driving up metastasis potential in cells. Thus MCP-1 and its mediated pathways could be potential therapeutic targets for the treatment of TNBC.

Citation Format: Pranabananda Dutta, Kimberly Paico, Inez Yuwanita, Yanyuan Wu, Marianna Sarkissyan, Jaydutt Vadgama. Upregulation of MCP-1 regulates invasiveness in triple negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1960. doi:10.1158/1538-7445.AM2017-1960

Abstract 111: Targeting STAT3 and telomerase for the treatment of colorectal cancer

There is an increasing evidence of pro-inflammatory cytokines involvement in cancer development. Here, we found that two cytokines, IL-6 and TNF-α, induced colorectal cancer cells more active and invasive. Combined treatments of IL-6 and TNF-α phosphorylated transcription factors STAT3 in a synergistic manner. STAT3 and NF-κB physically interacted upon cytokine stimulation. Similarly, STAT1 hetero-dimerized with STAT3 and the binding affinity was enhanced with cytokine treatments. STAT3 bound the promoter region of human telomerase reverse transcriptase (hTERT), and IL-6 and TNF-α stimulation further enhanced this STAT3 binding affinity. Withaferin A, an anti-inflammatory steroidal lactone, inhibited the IL-6 and TNF-α induced cancer cell invasiveness and decreased colonosphere formation. Notably, withaferin A inhibited STAT3 phosphorylation and abolished the STAT3 and NF-κB interactions. STAT3 binding to hTERT promoter was inhibited and telomerase activity was decreased with the withaferin A treatments. Taken together, pro-inflammatory cytokines induced-cancer cell invasiveness is mediated by STAT3 regulated mechanism in colorectal cancer cells. Our study suggests the novel natural compound therapy for the metastatic colorectal cancer in clinical settings.

Citation Format: Seyung Chung, Quincy Okobi, Debbie Adekoya, Jaydutt Vadgama. Targeting STAT3 and telomerase for the treatment of colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 111. doi:10.1158/1538-7445.AM2017-111

Long-term exposure of MCF-12A normal human breast epithelial cells to ethanol induces epithelial mesenchymal transition and oncogenic features

Alcoholism is associated with breast cancer incidence and progression, and moderate chronic consumption of ethanol is a risk factor. The mechanisms involved in alcohol's oncogenic effects are unknown, but it has been speculated that they may be mediated by acetaldehyde. We used the immortalized normal human epithelial breast cell line MCF-12A to determine whether short- or long-term exposure to ethanol or to acetaldehyde, using in vivo compatible ethanol concentrations, induces their oncogenic transformation and/or the acquisition of epithelial mesenchymal transition (EMT). Cultures of MCF-12A cells were incubated with 25 mM ethanol or 2.5 mM acetaldehyde for 1 week, or with lower concentrations (1.0–2.5 mM for ethanol, 1.0 mM for acetaldehyde) for 4 weeks. In the 4-week incubation, cells were also tested for anchorage-independence, including isolation of soft agar selected cells (SASC) from the 2.5 mM ethanol incubations. Cells were analyzed by immunocytofluorescence, flow cytometry, western blotting, DNA microarrays, RT/PCR, and assays for miRs. We found that short-term exposure to ethanol, but not, in general, to acetaldehyde, was associated with transcriptional upregulation of the metallothionein family genes, alcohol metabolism genes, and genes suggesting the initiation of EMT, but without related phenotypic changes. Long-term exposure to the lower concentrations of ethanol or acetaldehyde induced frank EMT changes in the monolayer cultures and in SASC as demonstrated by changes in cellular phenotype, mRNA expression, and microRNA expression. This suggests that low concentrations of ethanol, with little or no mediation by acetaldehyde, induce EMT and some traits of oncogenic transformation such as anchorage-independence in normal breast epithelial cells.

Abstract 5345: Enhanced inhibition of PC-3 xenograft prostate tumor growth by combination of green tea and quercetin with docetaxel

Chemotherapy with docetaxel (Doc) is a standard treatment for metastatic and castration-resistant prostate cancer. However, the development of chemoresistance and its side effects limit the clinical success of Doc. Previously we demonstrated that the combined use of natural products green tea (GT) and quercertin (Q) with Doc synergistically enhanced the anti-proliferative effect in androgen-independent prostate cancer PC-3 cells. The objective of the present study was to confirm the combined effect of GT, Q and Doc in xenograft prostate cancer mouse models and determine underlying mechanisms. Male severe combined immunodeficiency (SCID) mice (n = 10 per group) were inoculated with 5×105 PC-3 cells subcutaneously. When tumors reached a size of about 100mm3 the intervention started. Mice were administered with GT+Q, Doc 5mg/kg (LD), GT+Q+LD Doc, Doc 10mg/kg (HD) or control. The concentration of GT polyphenols in brewed tea administered as drinking water was 0.07% and Q was supplemented in diet at 0.4%. Doc was given through tail vein once a week for 4 weeks. There was a nonsignificant inhibition of tumor growth by GT+Q or LD Doc alone compared to control. However the combination treatment with GT+Q+LD Doc significantly inhibited the tumor growth by 62% compared to LD Doc alone after 7 weeks intervention. The combined effect was comparable to that by HD Doc treatment. Western blot analysis demonstrated a significantly increased ratio of Bax to Bcl-2 protein expression by GT+Q+LD Doc treatment compared to GT+Q or LD Doc. ELISA analysis of blood samples demonstrated that the combination treatment significantly decreased the blood concentrations of several growth factors, including VEGF, EGF, TGF-β, FGF-β, and TNF-α compared to GT+Q or LD Doc alone. A liver toxicity evaluation revealed that the blood alanine aminotransferase (ALT) level was significantly elevated with HD Doc treatment compared to control, while not changed by other groups. Further mechanistic investigations using protein array and tissue microarray assays are ongoing. This study provides a promising regimen by combining GT and Q with Doc to enhance chemotherapeutic effect in advanced prostate cancer in a less toxic manner. The results warrant future clinical trials to confirm the combined effect of the mixture in humans.

Citation Format: Piwen Wang, Susanne Henning, David Heber, Jaydutt Vadgama. Enhanced inhibition of PC-3 xenograft prostate tumor growth by combination of green tea and quercetin with docetaxel. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5345. doi:10.1158/1538-7445.AM2015-5345

Clinical significance of incidental colorectal wall thickening on computed tomography scan in African-American and Hispanic patients

We sought to assess the significance of an incidental finding of colorectal wall thickening (CRWT) on computed tomography (CT) scan in African-American and Hispanic patients. We retrospectively reviewed charts of African-American and Hispanic patients from January 1994 to December 2005. Those patients were included in whom the colonoscopy was performed due to incidental CRWT on CT scan. Patients with a history or a family history of colorectal malignancy, inflammatory bowel disease, or colorectal surgery, with an incomplete colonoscopic examination, or <18 years of age were excluded. Endoscopic and pathological findings were abstracted. Thirty-two patients met the criteria. Endoscopic examination was abnormal in 21 (65.6%). The positive predictive value of CRWT for abnormal endoscopic examination was 65.6%. Abnormal endoscopic examination revealed diverticulosis in 9 (43%), erythematous mucosa in 8 (38%), polyps in 6 (29%), mass in 2 (9%), thickened folds in 1 (5%), and diverticulitis in 1 (5%). Histopathological findings revealed colitis in 7 (33%), adenoma in 4 (19%), hyperplastic polyps in 4 (19%), adenocarcinoma in 2 (9%), lymphoid aggregates in 2 (9%), melanosis coli in 1 (5%), and normal in 1 (5%) in the abnormal examination group. Abnormal endoscopic examination was found in 65.6% of patients. The prevalence of colitis, adenomas, and malignancy was high, therefore abnormal CRWT warrants further endoscopic evaluation.

Elevated myocardial cytosolic calcium impairs insulin-like growth factor-1-stimulated protein synthesis in chronic renal failure

Rats and humans with chronic renal failure (CRF) are reported to have resistance to recombinant human insulin-like growth factor-1 (rhIGF-1). Because basal cytosolic calcium ([Ca2+]i), a second messenger, may be increased in CRF, this study was conducted to examine whether elevated basal [Ca2+]i may cause resistance to IGF-1. Cardiomyocytes from four groups of rats were studied: untreated CRF, CRF with parathyroidectomy (PTX), CRF with the calcium channel blocker felodipine (F), and sham operation of the kidney (SO). CRF was created by ligation of two-thirds of the left renal artery and contralateral nephrectomy. Rats from each group were pair-fed the same diet for 20 to 22 d. Basal [Ca2+]i in cardiomyocytes (nM) in the CRF rats (102.0 +/- 2.8; SEM), was significantly higher than in each of the CRF-PTX, CRF-F, and SO groups (65.2 +/- 1.9, 63.8 +/- 2.6, and 63.5 +/- 2.0, respectively; P < 0.01). rhIGF-1 increased cardiomyocyte [Ca2+]i in all four groups of rats. The rise in [Ca2+]i was significantly diminished in the CRF rats (P < 0.05) and did not differ among the CRF-PTX, CRF-F, and SO rats. Protein synthesis after incubation with 0, 50, 100, 200, or 400 ng/ml rhIGF-1 was lower in cardiomyocytes from CRF rats than in each of the other three groups (P < 0.05) and was significantly less in the CRF-F rats compared with SO animals. IGF-1 receptor mRNA and IGF-1 receptor number and affinity were not different among the four groups. These findings suggest that cardiomyocytes from CRF rats display elevated basal [Ca2+]i and attenuated rhIGF-1-induced increase in [Ca2+]i; basal protein synthesis is decreased, and IGF-1-stimulated protein synthesis is impaired; elevated basal [Ca2+]i seems to contribute to this diminished response to rhIGF-1.