Prevent Cancer Progression Research Articles

Abstract 1118: Stress-induced differential Survivin release in prostate cancer health disparities

Abstract African-American men have the highest rate of prostate cancer (PCa) incidence in the U.S. In addition, their prostate cancer mortality rate is more than twice as high as the rate for white Americans. The causes of higher rates of prostate cancer among African-American males are largely unknown. Many studies are underway to unravel the impact of a wide variety of potential risk factors, including dietary and other lifestyle differences, occupational exposures, hormonal and genetic differences. Several lines of evidence suggest that one of the main events associated with the conversion to an aggressive phenotype is increased resistance to apoptosis (3) mainly due to upregulation of antiapoptotic genes, including Bcl-2, Bcl-XL, Mcl-1, and Survivin. Recently, we reported that Survivin is released in PCa sera and found to be in the exosomes. Therefore, we speculate that Survivin could be a potential target protein released differentially in prostate cancers in African American (AA) and Caucasian (CC) populations in response to stress. In this study, we have collected serum samples from prostate cancer patients of AA and CC, measured Survivin levels by ELISA. Exosome islation was perfomed by Exoquick approach and quantified by acetylcholinesterase activity assays. We have applied an in-vitro approach to compare the differences between cancer cell lines derived from AA (MDA-MB-PCa) and CC (PC3) patients in terms of stress and stress activated Survivin release by exosomes. Under oxidative stress and drug treatments, we have identified Survivin highly expressed in exosome derived from MDA-MB-PCa compared to PC3 cell lines. In addition, we found a relative overexpression of Survivin protein in AA-PCa compared to CC-PCa both in sera and exosomes. Based on our data, Survivin may be a key stress-induced protein in AA-PCa patients. It is possible that attempts to block Survivin release will not only interrupt the cancer proliferation and interfere with anti-apoptotic pathways, thus preventing cancer progression. Citation Format: Salma Khan, David Turay, Jessica Ms Jutzy, Jonathan R. Aspe, Tino W. Sanchez, Saeid Mirshahidi, Carlos A. Casiano, Nathan R. Wall. Stress-induced differential Survivin release in prostate cancer health disparities. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1118. doi:10.1158/1538-7445.AM2014-1118

Abstract 5493: Metformin synergizes 5-fluorouracil, epirubicin, and cyclophosphamide (FEC) sensitivity in breast cancer stem cells and non-stem breast cancer cells

Abstract Incorporating cancer stem cells (CSCs)-targeting therapies into current therapies could prevent cancer progression, recurrence and metastasis. An anti-diabetic, AMPK-activating drug, metformin has been shown to kill CSCs and reduces cancer incidence and cancer related death. This study aimed to evaluate the combination treatment of metformin or other AMPK/mTOR-acting drugs with chemotherapy on breast CSCs and non-CSCs in the pre-clinical and clinical settings. We investigated the combination effect of metformin, AICAR, A-769662, or rapamycin with doxorubicin, cisplatin, paclitaxel, or FEC on breast CSCs (mammospheres) and non-CSCs in vitro. The study was extended clinically in a pilot study of ten non-diabetic locally advanced breast cancer patients treated with metformin and neoadjuvant FEC chemotherapy. Nine patients treated with FEC only were identified as historical controls. ESA+/CD44+/CD24-/low (CSCs) population of the tumor samples and tumor response were evaluated. In contrast to other drugs, metformin exhibited higher sensitivity in CSCs compared to attached cell lines. Metformin combined with FEC demonstrated a synergistic effect on breast CSCs and non-CSCs. Patients receiving metformin/FEC neoadjuvant therapy showed a significant reduction in CSCs proportion (P=0.008). Proportion of CSCs after treatment with metformin/FEC was significantly lower compared with the FEC-only neoadjuvant group (P=0.008). Five out of nine patients (56%) receiving metformin/FEC therapy showed a clinical response versus one out of eight (13%) patients in the FEC-only group. In conclusion, metformin synergizes FEC sensitivity in both CSCs and non-CSCs in breast cancer cell lines. Combination treatment of metformin and FEC reduces CSCs in primary tumor from non-diabetic locally advanced breast cancer patients. These results indicate that neoadjuvant metformin/FEC may be a potential treatment option for breast cancer patients and warrants further clinical investigations. Citation Format: Sian Siu Soo, Char Hong Ng, Rozita Abdul Malik, Yew Ching Teh, Boon Shing Tan, Gwo Fuang Ho, Mee Hoong See, Nur Aishah Mohd Taib, Cheng Har Yip, Soo Hwang Teo, Chee Onn Leong. Metformin synergizes 5-fluorouracil, epirubicin, and cyclophosphamide (FEC) sensitivity in breast cancer stem cells and non-stem breast cancer cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5493. doi:10.1158/1538-7445.AM2014-5493

TNF-α promotes invasive growth through the MET signaling pathway

The inflammatory cytokine Tumor Necrosis Factor Alpha (TNF-α) is known to trigger invasive growth, a physiological property for tissue healing, turning into a hallmark of progression in cancer. However, the invasive response to TNF-α relies on poorly understood molecular mechanisms. We thus investigated whether it involves the MET oncogene, which regulates the invasive growth program by encoding the tyrosine kinase receptor for Hepatocyte Growth Factor (HGF). Here we show that the TNF-α pro-invasive activity requires MET function, as it is fully inhibited by MET-specific inhibitors (small-molecules, antibodies, and siRNAs). Mechanistically, we show that TNF-α induces MET transcription via NF-κB, and exploits MET to sustain MEK/ERK activation and Snail accumulation, leading to E-cadherin downregulation. We then show that TNF-α not only induces MET expression in cancer cells, but also HGF secretion by fibroblasts. Consistently, we found that, in human colorectal cancer tissues, high levels of TNF-α correlates with increased expression of both MET and HGF. These findings suggest that TNF-α fosters a HGF/MET pro-invasive paracrine loop in tumors. Targeting this ligand/receptor pair would contribute to prevent cancer progression associated with inflammation.

The gut microbiota, bacterial metabolites and colorectal cancer.

Accumulating evidence suggests that the human intestinal microbiota contributes to the aetiology of colorectal cancer (CRC), not only via the pro-carcinogenic activities of specific pathogens but also via the influence of the wider microbial community, particularly its metabolome. Recent data have shown that the short-chain fatty acids acetate, propionate and butyrate function in the suppression of inflammation and cancer, whereas other microbial metabolites, such as secondary bile acids, promote carcinogenesis. In this Review, we discuss the relationship between diet, microbial metabolism and CRC and argue that the cumulative effects of microbial metabolites should be considered in order to better predict and prevent cancer progression.

A trial of co-cultivation: Confrontation of breast cancer spheroids and placenta tissue

Berberine is a pure phenanthren alkaloid isolated from the roots and bark of herbal plants such as Berberis, Hydrastis canadensis and Coptis chinensis. Berberine has been established to inhibit the growth of breast cancer cells, but its effects on the drug resistance and anoikis-resistance of breast cancer cells have yet to be elucidated. Anoikis, or detachment-induced apoptosis, may prevent cancer progression and metastasis by blocking signals necessary for survival of localized cancer cells. Resistance to anoikis is regarded as a prerequisite for metastasis; however, little is known about the role of berberine in anoikis-resistance. We established anoikis-resistant cells from the breast cancer cell lines MCF-7 and MDA-MB-231 by culturing them on a Poly-Hema substratum. We then investigated the effects of berberine on the growth of these cells. The anoikis-resistant cells had a reduced growth rate and were more invasive than their respective adherent cell lines. The effect of berberine on growth was compared to that of doxorubicine, which is a drug commonly used to treat breast cancer, in both the adherent and anoikis-resistant cell lines. Berberine promoted the growth inhibition of anoikis-resistant cells to a greater extent than doxorubicine treatment. Treatment with berberine-induced cell cycle arrest at G0/G1 in the anoikis-resistant MCF-7 and MDA-MB-231 cells as compared to untreated control cells. In summary, these results revealed that berberine can efficiently inhibit growth by inducing cell cycle arrest in anoikis-resistant MCF-7 and MDA-MB-231 cells. Further analysis of these phenotypes is essential for understanding the effect of berberine on anoikis-resistant breast cancer cells, which would be relevant for the therapeutic targeting of breast cancer metastasis.

An E2F1-HOXB9 transcriptional circuit is associated with breast cancer progression.

Homeobox B9 (HOXB9), a member of the homeobox gene family, is overexpressed in breast cancer and promotes tumor progression and metastasis by stimulating epithelial-to-mesenchymal transition and angiogenesis within the tumor microenvironment. HOXB9 activates the TGFβ-ATM axis, leading to checkpoint activation and DNA repair, which engenders radioresistance in breast cancer cells. Despite detailed reports of the role of HOXB9 in breast cancer, the factors that regulate HOXB9 transcription have not been extensively examined. Here we uncover an underlying mechanism that may suggest novel targeting strategies for breast cancer treatment. To identify a transcription factor binding site (TFBS) in the HOXB9 promoter region, a dual luciferase reporter assay was conducted. Protein candidates that may directly attach to a TFBS of HOXB9 were examined by Q-PCR, electrophoretic mobility shift assay (EMSA), chromatin immunoprecipitation (ChIP), and mutation analysis. A HOXB9 promoter region from −404 to −392 was identified as TFBS, and E2F1 was a potential binding candidate in this region. The induction of HOXB9 expression by E2F1 was observed by Q-PCR in several breast cancer cell lines overexpressing E2F1. The stimulatory effect of E2F1 on HOXB9 transcription and its ability to bind the TFBS were confirmed by luciferase, EMSA and ChIP assay. Immunohistochemical analysis of 139 breast cancer tissue samples revealed a significant correlation between E2F1 and HOXB9 expression (p<0.001). Furthermore, a CDK4/6 inhibitor suppressed E2F1 expression and also reduced expression of HOXB9 and its downstream target genes. Our in vitro analysis identified the TFBS of the HOXB9 promoter region and suggested that E2F1 is a direct regulator of HOXB9 expression; these data support the strong correlation we found between E2F1 and HOXB9 in clinical breast cancer samples. These results suggest that targeting the E2F1/HOXB9 axis may be a novel strategy for the control or prevention of cancer progression and metastasis.

Malic enzyme is a target for drug design to combat obesity and cancer

The cytosolic malic enzyme (ME1) plays an important role in insulin-induced lipogenesis and has profound effects on colon cancer progression. ME1 generates pyruvate, NADPH and carbon dioxide from malate, a Krebs cycle intermediate. NADPH has an important role in de novo synthesis of long-chain fatty acids whereas pyruvate is cycled back into mitochondria. The pyruvate cycle has been hypothesized to be a necessary component of glucose-stimulated insulin secretion. Increased insulin signaling in liver and adipose tissues leads to higher accumulation of fat mass increasing the risk for obesity. NADPH and fatty acids also support cancer cell proliferation and migration. Thus ME1 may be a suitable drug target to counter obesity and prevent cancer progression. In the current work, computer-aided drug design techniques were used to identify possible ME1 inhibitors with therapeutic value. The software package SYBYL was used for defining the binding pocket and virtual screening was performed to mine through large databases (ZINC-UCSF) containing drug-like molecules in order to identify molecules that could form hydrogen bonds to the enzyme and fit into the active site. The molecules so obtained were then used for docking using the software packages SURFLEX DOCK (SYBYL) and AutoDock Vina (Scripps Research Institute). Lead molecules having minimum binding energy score were identified and two in vitro assays were carried out on the top hit molecules. We tested a total of 11 compounds for activity using an enzyme assay and 4 of these compounds were found to diminish NADPH production significantly. Additionally we performed a cell proliferation assay with colorectal cancer cell line (HCT-116) using the above 4 compounds and three of these compounds exhibited strong activity against cancer cell growth. Supported in part by NIH grant CA136493.

Lapatinib for the treatment of breast cancer in the People's Republic of China.

Lapatinib is an oral, small-molecule, reversible inhibitor of both epidermal growth factor receptor and human epidermal growth factor receptor–2 (HER2) tyrosine kinases. In March 2007, the US Food and Drug Administration approved lapatinib for use in combination with capecitabine for the treatment of women with HER2-overexpressing, advanced or metastatic breast cancer. This review discusses the available information of lapatinib in Chinese breast cancer patients, focusing on its effectiveness and clinical application against advanced or metastatic breast cancer. In pivotal phase III trials, a combination of lapatinib and capecitabine significantly decreased the risk of disease progression compared to capecitabine alone in women with HER2-positive advanced or metastatic breast cancer. Other trials were used to evaluate lapatinib in combination with hormone therapy, in combination with trastuzumab, and as an adjunct to adjuvant therapy for early-stage disease. Preclinical data have revealed that lapatinib is active in trastuzumab-resistant cell lines as well as synergistic with trastuzumab. In clinical trials, lapatinib has not been associated with serious or symptomatic cardiotoxicity. Further, it can cross the blood–brain barrier and may therefore have a role in preventing cancer progression in the central nervous system. Thus, lapatinib warrants further evaluation in HER2-positive metastatic and early-stage breast cancer patients.

Exercise enhances wound healing and prevents cancer progression during aging by targeting macrophage polarity

Physical activity, which can include regular and repetitive exercise training, has been shown to decrease the incidence of age-related diseases. Aging is characterized by aberrant immune responses, including impaired wound healing and increased cancer risk. The behavior and polarized phenotype of tissue macrophages are distinct between young and old organisms. The balance of M1 and M2 macrophages is altered in the aged tissue microenvironment, with a tilt towards an M2-dominant macrophage population, as well as its associated signaling pathways. These M2-type responses may result in unresolved inflammation and create an environment that impairs wound healing and is favorable for cancer growth. We discuss the concept that exercise training can improve the regulation of macrophage polarization and normalize the inflammatory process, and thereby exert anticancer effects and enhance wound healing in older humans.

Metformin inhibits mitochondrial complex I of cancer cells to reduce tumorigenesis.

Recent epidemiological and laboratory-based studies suggest that the anti-diabetic drug metformin prevents cancer progression. How metformin diminishes tumor growth is not fully understood. In this study, we report that in human cancer cells, metformin inhibits mitochondrial complex I (NADH dehydrogenase) activity and cellular respiration. Metformin inhibited cellular proliferation in the presence of glucose, but induced cell death upon glucose deprivation, indicating that cancer cells rely exclusively on glycolysis for survival in the presence of metformin. Metformin also reduced hypoxic activation of hypoxia-inducible factor 1 (HIF-1). All of these effects of metformin were reversed when the metformin-resistant Saccharomyces cerevisiae NADH dehydrogenase NDI1 was overexpressed. In vivo, the administration of metformin to mice inhibited the growth of control human cancer cells but not those expressing NDI1. Thus, we have demonstrated that metformin's inhibitory effects on cancer progression are cancer cell autonomous and depend on its ability to inhibit mitochondrial complex I.DOI: http://dx.doi.org/10.7554/eLife.02242.001.

Interview with Donald E Ingber.

Interview with Donald E Ingber.

Licochalcone A suppresses migration and invasion of human hepatocellular carcinoma cells through downregulation of MKK4/JNK via NF-κB mediated urokinase plasminogen activator expression.

Hepatocellular cell carcinoma (HCC) is one of the most commonly diagnosed cancers worldwide and in Taiwan. Chemoprevention of cancer with dietary bioactive compounds could potentially reverse, suppress, or prevent cancer progression. Licochalcone A (LicA) is a characteristic chalcone of licorice, which is the root of Glycyrrhiza inflate. It had been reported that LicA has anti-inflammatory, anti-microbial, and anti-tumor properties. However, the effects of LicA on the migration and invasion of human HCC cells have not yet been reported. In the present study, it was found that LicA inhibits the migratory and invasion ability of SK-Hep-1 and HA22T/VGH cells in a dose-dependent manner, as assessed by the cell migration and Matrigel cell invasion assay. Using casein zymography, Western blotting, reverse transcriptase polymerase chain reaction, and an immunofluorescence assay, it was found that LicA induces a dose-dependent inhibition of uPA activity and expression, as well as reduces mRNA levels in SK-Hep-1 and HA22T/VGH cells. LicA was also found to inhibit the expression of phosphor-JNK and phosphor-MKK4 in SK-Hep-1 cells. Furthermore, LicA significantly decreased uPA levels in SP600125-treated or si-MKK4-transfected cells alongside a marked reduction in cell migration and invasion, which supports the notion that an inhibition of MKK4/JNK results in anti-metastatic effects. Moreover, LicA inhibited the expression of nuclear NF-κB, as well as the binding ability of NF-κB to the uPA promoter. These findings further our understanding of the role of LicA in suppressing tumor metastasis and its underlying molecular mechanisms, as well as suggest that LicA may be a promising anti-metastatic agent.

Biomarkers for screening of lung cancer and pre-neoplastic lesions in a high risk Chilean population.

BackgroundThe mortality of lung cancer (LC), increases each year in the world, in spite of any advances, in development of new drugs to advance stages of LC. The high incidence of LC has been associated with smoking habit, genetic diversity and environmental pollution. Antofagasta region has been reported to have the highest LC mortality rate in Chile and its inhabitants were exposed to arsenic in their drinking water in concentrations as high as 870 μg/L. Non-invasive techniques such as biomarkers (Automatic Quantitative Cytometry: AQC and DR70) and Auto Fluorescence Bronchoscopy (AFB) might be potentially useful as a supplementary diagnostic approach and early detection. Early detection is one of the most important factors to intervene and prevent cancer progression in LC. This is a work of an ongoing prospective bimodality cancer surveillance study in high risk LC volunteers. Enrolment was done in subjects from Antofagasta and Metropolitan regions. In addition, we enrolled subjects who were suspected of having lung cancer. AQC, DR70 and AFB were used as tools in the detection of pre-neoplastic (PNL) and neoplastic lesions (NL).ResultsHalf of the samples, classified as suspicious by AFB, were confirmed as metaplasia or dysplasia by histopathology. For LC, DR70 showed a higher sensitivity (95.8%) and specificity (91.9%) than AQC. However, for PNL AQC showed a higher sensitivity (91.9%) than DR70 (27.3%), although both with low PPV values. As a pre screener, both biomarkers might be employed as complementary tools to detect LC, especially as serially combined tests, with a sensitivity of 60% and a PPV of 65.2%. Additionally, the use of parallel combined tests might support the detection of PNL (sensitivity 91.2%; PPV 49.1%).ConclusionThis work adds information on cellular and molecular biomarkers to complement imaging techniques for early detection of LC in Latin America that might contribute to formulate policies concerning screening of LC. Supported by INNOVA-CORFO, Chile.

Vav1 is ectopically expressed in breast tumors in which reduces the efficiency of the metastatic process

Vav1, normally restricted to hematopoietic cells, results ectopically expressed in solid tumors, including breast cancer (Sebban et al., 2013) in which, contrarily to other neoplasias, seems to be higher in tumors from patients who remained diseasefree than in patients who developed recurrence (Lane et al., 2008). The significance of Vav1 expression in breast tumors was evaluated by immunohistochemical analysis on TMAs containing invasive breast tumors from patients without lymph node involvement. Our findings indicate that Vav1 is expressed in almost all investigated cancers and shows a peculiar localization inside the nucleus of tumor cells. High amounts of nuclear Vav1 positively correlates with low incidence of relapse, regardless phenotype and molecular subtype of the neoplasia. Experiments performed with breast tumor-derived cells showing different morphology, immunoprofile and invasive properties indicated that Vav1 negatively modulates their invasiveness in vitro and their metastatic efficiency in vivo, possibly by affecting the expression of genes involved in invasion and/or metastasis of breast cancer. Since the high heterogeneity of breast tumors makes difficult to predict the evolution of early neoplasias, the evaluation of nuclear Vav1 levels may help in profiling and management of early breast cancer patients. In addition, Vav1 may serve as a target for new therapies designed to prevent breast cancer progression.

Chemotherapy After Portal Vein Embolization to Protect Against Tumor Growth During Liver Hypertrophy Before Hepatectomy

Portal vein embolization improves the safety of liver resection by increasing the size of residual liver, but the embolization may increase tumor growth during the waiting period before definitive hepatectomy. To determine whether the administration of chemotherapy mitigates tumor growth after portal vein embolization (PVE) performed before major hepatectomy for metastatic colorectal cancer. Review of prospectively collected data at Memorial-Sloan Kettering Cancer Center was conducted. The database included patients subjected to PVE before major hepatectomy for metastatic colorectal cancer. Lesions in both the embolized and nonembolized lobes of the liver before and 1 month after PVE were measured and Response Evaluation Criteria in Solid Tumors were applied to assess disease status. Assessment of survival was based on receipt of post-PVE chemotherapy and then stratified by subsequent resectability. Two hundred eight tumors were measured in 64 patients; 53 tumors were in patients undergoing post-PVE chemotherapy. Approximately one-third of the lesions progressed after PVE when no chemotherapy was administered. This did not differ significantly according to whether tumors were ipsilateral or contralateral to the PVE. When chemotherapy was administered, there was a significantly lower rate of progression (18.9%, P = .03). In long-term follow-up, treatment with post-PVE chemotherapy was also independently associated with improved survival (P < .006). Chemotherapy does not retard growth of the liver after PVE and may prevent cancer progression. Thus, the combination of PVE and chemotherapy may enhance both oncologic and operative safety.

Targeting inhibitor 2 of protein phosphatase 2A as a therapeutic strategy for prostate cancer treatment

Inhibitor 2 of protein phosphatase 2A (I2PP2A), a biological inhibitor of the cellular serine/threonine protein phosphatase PP2A, is associated with numerous cellular processes that often lead to the formation and progression of cancer. In this study we hypothesized that targeting the inhibition of I2PP2A’s multiple functions in prostate cancer cells might prevent cancer progression. We have investigated the effect of the small chain C6-ceramide, known to be a bioactive tumor suppressor lipid, on I2PP2A function, thereby affecting c-Myc signaling and histone acetylation in cells. Our data indicated that C6-ceramide treatment of prostate cancer cells induces cell death in PC-3, DU145, and LNCaP cells, but not normal prostate epithelial cells. C6-ceramide was able to disrupt the association between PP2A and I2PP2A. C6-ceramide inhibits I2PP2A’s upregulation of c-Myc and downregulation of histone acetylation in prostate cancer cells. Our data indicated that targeting cancer related signaling pathways through I2PP2A using ceramide as an anti-I2PP2A agent could have beneficial effects as a therapeutic approach to prevent prostate cancer.

Breast cancer mortality among users of cholesterol-lowering drugs.

1514 Background: Breast cancer is a common malignancy and cause of cancer death. Recent studies have suggested that statins, an established cholesterol-lowering drug group used in the prevention of cardiovascular mortality, could have beneficial effects against recurrence and progression of breast cancer. We evaluated breast cancer-specific mortality among users of statins and other cholesterol-lowering drugs (fibrates and bile-acid binding resins) in a cohort of breast cancer patients. Methods: Our study cohort included all newly diagnosed breast cancer patients in Finland during 1995-2003 (31,236 cases), identified from the Finnish Cancer Registry. Information on cholesterol-lowering medication use was obtained from a national prescription database.We used Cox proportional hazards regression method to estimate mortality among medication users. Results: A total of 4,169 participants had used statins, while 313 had used fibrates or resins. Despite similar median age, tumor and treatment characteristics, only statin use was associated with decreased breast cancer mortality (participants with localized tumors: HR 0.33, 95% CI 0.24-0.42; metastatic tumors: HR 0.52, 95% CI 0.31-0.86). Fibrate and resin use were associated with increased overall mortality (HR 1.70, 95% CI 0.96-2.99 for participants with localized disease, HR 2.65, 95% CI 1.18-5.96 for participants with metastatic disease). Conclusions: Decreased breast cancer mortality among users of statins, but not other cholesterol-lowering drugs despite similar population characteristics suggests that this drug group may have benefit in prevention of cancer progression. Clinical trials testing statins’ efficacy in breast cancer patients are warranted.

Iodine Uptake and Prostate Cancer in the TRAMP Mouse Model

Iodine supplementation exerts antitumor effects in several types of cancer. Iodide (I⁻) and iodine (I₂) reduce cell proliferation and induce apoptosis in human prostate cancer cells (LNCaP and DU-145). Both chemical species decrease tumor growth in athymic mice xenografted with DU-145 cells. The aim of this study was to analyze the uptake and effects of iodine in a preclinical model of prostate cancer (transgenic adenocarcinoma of the mouse prostate [TRAMP] mice/SV40-TAG antigens), which develops cancer by 12 wks of age. ¹²⁵I⁻ and ¹²⁵I₂ uptake was analyzed in prostates from wild-type and TRAMP mice of 12 and 24 wks in the presence of perchlorate (inhibitor of the Na⁺/I⁻ symporter [NIS]). NIS expression was quantified by quantitative polymerase chain reaction (qPCR). Mice (6 wks old) were supplemented with 0.125 mg I⁻ plus 0.062 mg I₂/mouse/day for 12 or 24 wks. The weight of the genitourinary tract (GUT), the number of acini with lesions, cell proliferation (levels of proliferating cell nuclear antigen [PCNA] by immunohistochemistry), p53 and p21 expression (by qPCR) and apoptosis (relative amount of nucleosomes by enzyme-linked immunosorbent assay) were evaluated. In both age-groups, normal and tumoral prostates take up both forms of iodine, but only I⁻ uptake was blocked by perchlorate. Iodine supplementation prevented the overexpression of NIS in the TRAMP mice, but had no effect on the GUT weight, cell phenotype, proliferation or apoptosis. In TRAMP mice, iodine increased p53 expression but had no effect on p21 (a p53-dependent gene). Our data corroborate NIS involvement in I⁻ uptake and support the notion that another transporter mediates I₂ uptake. Iodine did not prevent cancer progression. This result could be explained by a strong inactivation of the p53 pathway by TAG antigens.

Score As You Lift (SAYL): A Statistical Relational Learning Approach to Uplift Modeling.

We introduce Score As You Lift (SAYL), a novel Statistical Relational Learning (SRL) algorithm, and apply it to an important task in the diagnosis of breast cancer. SAYL combines SRL with the marketing concept of uplift modeling, uses the area under the uplift curve to direct clause construction and final theory evaluation, integrates rule learning and probability assignment, and conditions the addition of each new theory rule to existing ones. Breast cancer, the most common type of cancer among women, is categorized into two subtypes: an earlier in situ stage where cancer cells are still confined, and a subsequent invasive stage. Currently older women with in situ cancer are treated to prevent cancer progression, regardless of the fact that treatment may generate undesirable side-effects, and the woman may die of other causes. Younger women tend to have more aggressive cancers, while older women tend to have more indolent tumors. Therefore older women whose in situ tumors show significant dissimilarity with in situ cancer in younger women are less likely to progress, and can thus be considered for watchful waiting. Motivated by this important problem, this work makes two main contributions. First, we present the first multi-relational uplift modeling system, and introduce, implement and evaluate a novel method to guide search in an SRL framework. Second, we compare our algorithm to previous approaches, and demonstrate that the system can indeed obtain differential rules of interest to an expert on real data, while significantly improving the data uplift.

Sabutoclax, a Novel Pan BCL2 Family Inhibitor, Sensitizes Dormant Blast Crisis Chronic Myeloid Leukemia Stem Cells to Dasatinib

AbstractAbstract 3739Leukemia stem cells (LSC) represent a frequently dormant self-renewing population integral to the initiation, maintenance, and progression of human chromic myeloid leukemia (CML). The current standard of care dasatinib, a BCR-ABL targeted tyrosine kinase inhibitor (TKI), effectively eradicates the bulk of CML cells but frequently fails to affect the LSC population that is thought to drive CML relapse. Members in the BCL2 family are proteins that regulate apoptosis, 6 of which regulate cell survival. Each of these 6 members has a long and short isoform with opposing functions; generally, long isoforms promote cell survival while the short isoforms promote apoptosis. Previously, we demonstrated that upregulation of pro-survival BCL2 proteins in CML LSC contributes to chemotherapy resistance and LSC quiescence in protective hematopoietic niches. LSC found in different hematopoietic niches differ in their response to TKI treatment. Niche affects LSC cell cycle, either by maintaining quiescence or by promoting rapid cell cycling. Quiescent cells are a hurdle for traditional chemotherapy, which usually targets rapidly cycling cells, leaving the quiescent LSC untouched. We hypothesize that the inhibition of pro-survival BCL2 protein family members will sensitize LSC to dasatinib therapy and therefore prevent CML relapse.We tested a novel pan pro-survival BCL2 family protein inhibitor, sabutoclax, delivered by intravenous injection either alone or in combination with oral dasatinib in immunodeficient RAG2−/-gc−/- mice engrafted with BC CML patient samples. After treatment, LSC burden, self-renewal, and cell cycle status were quantified using FACS. Our results showed a reduction in the LSC burden in combination treated mice when compared to mice that received either drug alone. Mice treated with the combination regimen were found to have fewer quiescent human leukemic cells than their counterparts that received single agent treatments. Immunofluorescence staining confirmed the reduction of quiescent cells in the bone marrow after combination treatment when compared to single agent or vehicle treatments. We validated the molecular targets by using human specific splice isoform primers to perform RT-qPCR on FACS sorted LSC and showed a reduction in the BCL2 long to short isoform ratio in sabutoclax versus vehicle treated animals, indicating a skewing towards the pro-apoptotic splice variant. Together, these results indicate that the combination strategy with a pan pro-survival BCL2 family inhibitor and a tyrosine kinase inhibitor may be the foundation for a promising clinical strategy to effectively eliminate LSC and prevent cancer progression and relapse. Disclosures:No relevant conflicts of interest to declare.