Seema Dubey

Geographical Clines for Quantitative Traits in Natural Populations of a Tropical Drosophilid: Zaprionus Indianus

We analyzed natural populations of Zaprionus indianusin 10 Indian localities along a south-north transect (latitude: 10–31°3 N). Size traits (body weight, wing length and thorax length) as well as a reproductive trait (ovariole number) followed a pattern of clinal variation, that is, trait value increased with latitude. Wing/thorax ratio, which is inversely related to wing loading, also had a positive, but non-significant correlation with latitude. By contrast, bristle numbers (sternopleural and abdominal) exhibited a non-significant but negative correlation with latitude. Sex dimorphism, estimated as the female/male ratio, was very low in Z. indianus, contrasting with results already published in other species. Genetic variations among populations were also analyzed according to other geographic parameters (altitude and longitude) and to climatic conditions from each locality. A significant effect of altitude was found for size traits. For abdominal bristles, a multiple regression technique evidenced a significant effect of both latitude and altitude, but in opposite directions. Genetic variations were also correlated to climate, and mainly with average year temperature. Taking seasonal variations into account failed however to improve the predictability of morphometrical variations. The geographic differentiation of Z.indianusfor quantitative traits suggests adaptive response to local conditions, especially to temperature, but also reveals a complex situation according to traits investigated and to environmental parameters, which does not match results on other drosophilid species.

Dual antigen target-based immunotherapy for prostate cancer eliminates the growth of established tumors in mice.

AIMS We have previously shown that immunization with an adenovirus vector carrying an individual antigen induces antigen-specific CD8 T cells actively engaged in the destruction of tumor cells expressing the cognate antigen. In order to expand the range of antitumor responses beyond an individual antigen, we designed a recombinant adenovirus type 5 (rAd5) carrying a fusion construct of two full-length antigens. We used this adenovirus vector to test the concept that multiantigenic effector T cells could be generated simultaneously following a single immunization. METHOD To perform the rAd5 constructs, we selected a combination of prostate-specific antigen (PSA) and prostate stem cell antigen (PSCA) genes based on their restricted distribution within the prostate tissue and their association with the development and progression of prostate cancer. RESULTS Immunization of mice with rAd5 vector carrying a fusion construct of PSA and PSCA (Ad5-PSA/PSCA) simultaneously induced the expansion of anti-PSA and anti-PSCA CD8 T cells, as measured by intracellular cytokine staining for IFN-γ. The antigen-specific T-cell responses that developed were efficient in eliminating the target cells expressing cognate antigens measured by an in vivo cytotoxic T-cell assay. The in vivo tumor growth study showed that immunization of mice with Ad5-PSA/PSCA vaccine induced strong antitumor immunity when challenged with mouse prostate tumor cell lines (RM11) expressing human PSA (RM11/PSA). To further analyze the impact on therapeutic efficacy of Ad5-PSA/PSCA vaccine against the tumor cells expressing PSA and PSCA (RM11-PSA/PSCA) antigens, we injected mice with Ad5-PSA/PSCA vaccine. The vaccine inhibited the growth of established tumors with 80% of the mice becoming tumor free. These data provide useful information that antigen-specific effector T cells can be generated simultaneously and that their additive antitumor effect has the potential to eliminate the growth of established tumors. Therefore, the immunotherapy approach of using the simultaneous targeting of dual antigens associated with prostate cancer may have important implications for human clinical trials.

From Inflammation to Prostate Cancer: The Role of Inflammasomes

Inflammation-associated studies entice specific attention due to inflammations role in multiple stages of prostate cancer development. However, mechanistic regulation of inflammation inciting prostate cancer remains largely uncharacterized. A focused class of inflammatory regulators known as inflammasomes has recently gained attention in cancer development. Inflammasomes are a multiprotein complex that drives a cascade of proinflammatory cytokines regulating various cellular activities. Inflammasomes activation is linked with infection, stress, or danger signals, which are common events within the prostate gland. In this study, we review the potential of inflammasomes in understanding the role of inflammation in prostate cancer.

Expression analysis of inflammasome sensors and implication of NLRP12 inflammasome in prostate cancer

Inflammasomes are multi-proteins complex regulating inflammation-associated signaling. While inflammation plays a critical role in cancer cell growth, studies remain uncharacterized on the role of inflammasomes in prostate cancer. Using Gene Expression Omnibus (GEO) public datasets, we screened the expression profiles of inflammasome sensors NLRP3, NLRC4, NLRP6, NRLP12, and AIM2 in prostate tumor tissues, and verified their mRNA level in a panel of prostate cancer cell lines. The selected expression of NLRP3 and NLRP12 inflammasomes was validated, and the clinical association was evaluated in human prostate archival tumor tissues. We observed that the expression of inflammasome sensors was dysregulated at the mRNA level except for the NLRP12. The intensity of NLRP12 immunostaining was significantly higher in malignant prostate as compared to their adjacent benign tissues. In contrast, the NLRP3 immunostaining in prostate tissues was heterogeneous. The inflammasome complex proteins ASC (apoptosis-associated speck-like protein containing a CARD) and pro-caspase-1, as well as its downstream targets IL-1β and IL-18 were confined to aggressive prostate cancer cells. These data suggest an increased expression of NLRP12 in association with prostate cancer and support the role of NLRP12 inflammasome complex regulating inflammatory cytokines in understanding the role of inflammation in the prostate cancer.

Withaferin A Associated Differential Regulation of Inflammatory Cytokines

A role of inflammation-associated cytokines/chemokines has been implicated in a wide variety of human diseases. Here, we investigated the regulation of inflammatory cytokines released by monocyte-derived THP-1 cells following treatment with the dietary agent withaferin A (WFA). Membrane-based cytokine array profiling of the culture supernatant from adenosine triphosphate-stimulated WFA-treated THP-1 cells showed differential regulation of multiple cytokines/chemokines. A selected group of cytokines/chemokines [interleukin-1 beta (IL-1β), CCL2/MCP-1, granulocyte-macrophage colony stimulating factor, PDGF-AA, PTX3, cystatin-3, relaxin-2, TNFRSF8/CD30, and ACRP30] was validated at the transcription level using qPCR. In silico analysis for transcriptional binding factors revealed the presence of nuclear factor-kappa B (NF-κB) in a group of downregulated cytokine gene promoters. WFA treatment of THP-1 cells blocks the nuclear translocation of NF-kB and corresponds with the reduced levels of cytokine secretion. To further understand the differential expression of cytokines/chemokines, we showed that WFA alters the nigericin-induced co-localization of NLRP3 and ASC proteins, thereby inhibiting caspase-1 activation, which is responsible for the cleavage and maturation of pro-inflammatory cytokines IL-1β and IL-18. These data suggest that dietary agent WFA concurrently targets NF-κB and the inflammasome complex, leading to inhibition of IL-1β and IL-18, respectively, in addition to differential expression of multiple cytokines/chemokines. Taken together, these results provide a rationale for using WFA to further explore the anti-inflammatory mechanism of cytokines/chemokines associated with inflammatory diseases.

Abstract B12: Macrophage inhibitory cytokine-1 as a potential biomarker for racial disparity in prostate cancer

Macrophage inhibitory cytokine-1 (MIC-1) has drawn significant attention due to its association with the development and progression of prostate cancer (PCa). Recent studies have projected MIC-1 as a potential biomarker for various disease conditions including PCa. Given evidence for more aggressive disease among African American (AA) men, we aimed to investigate if MIC-1 was differentially expressed among AA and Caucasian men. We measured serum MIC-1 levels by sandwich ELISA in samples collected during the diagnosis of PCa (pre-surgical). Our data consists of information on 40 Caucasian and 40 AA men between the ages of 43 and 75 years (Median = 60 years). Based on the analysis of log transformation of the data, significant differences among the two races were found, with AA having higher MIC-1 expression (Median 1220.4 versus 790.8, p=0.0001), Gleason scores (Median 7 versus 6, p=0.0009) and PSA (Median 6.72 versus 6.35 ng/ml, p = 0.04) than Caucasians. No differences in age or pathological stage of disease were observed between groups (p > 0.05). Higher levels of MIC-1 and Gleason scores were associated (p Citation Format: Dev Karan, Seema Dubey, Jo Wick, Ossama Tawfik, Guru Sonpavde, Peter VanVeldhuizen. Macrophage inhibitory cytokine-1 as a potential biomarker for racial disparity in prostate cancer. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr B12.

Gene expression profile of CD8 T cells from the responder and non-responder mice following immunotherapy treatment for prostate cancer

Immunotherapy represents a novel treatment approach for cancer; however, a longer maturation time and the lack of immunological markers are major obstacles in the development and characterization of immunological therapies. This study aims t oi dentify gene expression profile on CD8+ T cells between the responder (completely regressed tumors) and non-responder (progressively growing tumors) groups of mice helpful in predicting the outcome of immunotherapy treatment. Using a preclinical mouse model for prostate cancer, subcutaneous tumors were established and the mice were treated with Ad-PSA+PSCA bivalent vaccine. Splenic CD8+ T cells purified from the responder and non-responder groups of mice were subjected to Affymetrix microarray to obtain gene expression profile. Pooling the data sets from two independent experiments revealed an up-regulation of 85 genes (>2.0 fold; p =2.7e-63) and down-regulation of 1768 gene (>2.0 fold; p =1.0e-63) in CD8+ T cells from the non-responder mice. Gene network analysis showed a coordinated expression of genes implicated in cellmediated immune response, cell-to-cell signaling and interaction, and immune cell trafficking. The mRNA expression levels for the selected transcripts were verified using semi-quantitative RT-PCR method suggesting a panel of genes specific to CD8+ T cells differentially expressed between the responder and non-responder mice. Further studies are warranted to determine the potential of these identified genes as immunological biomarker to predict immunotherapy response.