Sham S. Kakar, Ph.D., MBA

Education:Sham Kakar, Ph.D.

B.S., Panjab University, India; 1973
Ph.D., Biochemistry, Kurukshetra University, India; 1983
Postdoctoral Fellowship, Baylor College of Medicine, Houston, TX; 1983
MBA, Entrepreneurship, University of Louisville, Louisville, KY; 2010

Curriculum Vitae

Current Positions:

Professor, Department of Physiology
Professor, Department of Biochemistry and Molecular Genetics
Professor, Division of Endocrinology and Metabolism
Member, Cancer Care & Control Program, James Graham Brown Cancer Center
Member, Institute for Molecular Diversity and Drug Design (IMD3), University of Louisville
Member, Center for Genetics and Molecular Medicine (CGeMM)
University of Louisville School of Medicine

Contact Information:

Clinical Translational Research Building, Room 322
University of Louisville
505 Hancock St.
Louisville, KY 40202, USA
Phone 502-852-0812
Fax 502-852-2123

Email: sskaka01@louisville.edu

Research Description

The Kakar lab is focused in using models of human cancer to elucidate the mechanisms of tumor initiation, progression and regression following therapeutic intervention. To this end, we have adopted a philosophy of combining pre-clinical models with biochemistry, molecular biology and cultured human cells to dissect signaling pathways and cellular processes involved in all aspects of cancer biology including recurrence of cancer, stem cell biology. The following are the active research projects in Kakar’s research lab.

Development of a Novel Combination Therapy for Ovarian Cancer

Epithelial ovarian cancer (EOC) remains the leading cause of death in women with gynecologic cancers and the 5th highest cause of cancer-related deaths in women in the United States. Currently, the treatment for ovarian cancer entails cytoreductive surgery followed by chemotherapy, mainly, carboplatin coupled with paclitaxel. Although this treatment regimen is initially effective in a high percentage of cases, it is associated with severe side effects and within 6 to 24 months of initial treatment, tumor relapse occurs, which is attributed to the carcinomas having become platinum-resistant. Due to the poor survival of women with platinum-resistant carcinomas, and the severe side effects an alternative treatment strategy is warranted. We developed a novel strategy that combines cisplatin with Withaferin A (WFA). WFA, a bioactive compound isolated from the plant Withania somnifera, is used in the US as an over-the-counter dietary supplement. More recently, it has been shown to prevent tumor growth, angiogenesis, and metastasis. In addition, WFA has been reported to inhibit Notch 1 signaling an important signaling pathway for the self-renewal and maintenance of cancer stem cell population. Based on this information, we hypothesize that a novel combination of Withaferin A and cisplatin can target ovarian cancer cells and also ovarian cancer stem cells, which can reduce the cisplatin side effects and recurrence of ovarian cancer. Our hypothesis is supported by our preliminary studies in which epithelial ovarian cancer cell lines (A2780 and CaOV3 and A2780/CP70) when co-treated with low doses of the WFA (1.5 μM) and cisplatin (20 μM), resulted in inhibiting 80 to 90% cell proliferation within 48 h of treatment. In contrast, same concentration of each drug when used alone exhibited only 15% to 20% inhibition, respectively. In addition, treatment of nude mice bearing orthotopic ovarian tumors with WFA/cisplatin combination resulted in 80 to 90% reduction in tumor growth and complete inhibition of metastasis to other organs. The project seeks to: Determine 1) the optimum combination doses of WFA and cisplatin to completely suppress/regress ovarian tumor growth, metastasis and recurrence of ovarian tumor, 2) effect on ovarian cancer stem cells population, 3) effects of infiltration of macrophages, 4) bioavailability and pharmacokinetics of cisplatin and WFA and molecular mechanisms associated with the antitumor effects of WFA/CIS combination.

The study will provide important information for the application of WFA and cisplatin combination strategy to suppress/regress ovarian cancer growth while minimizing/eliminating the severe side effects and induction of multidrug resistance and recurrence of cancer. In addition this study should have worldwide impact on patients suffering or dying from ovarian cancer, and will justify the initiation of phase I/phase II clinical trials to assess potential toxicity and efficacy of WFA/CIS combination in advanced ovarian cancer patients.

Targeting of Cancer Cells and cancer Stem Cells in Ovarian Cancer

Tumor relapse and recurrence has been attributed due to the presence of cancer stem cells (CSCs). The CSCs are a small population (2-5%) of cells in solid cancer which are chemo-resistant, highly tumorigenic, possess a self-renewal capacity, and the capability to differentiate into multiple lineage. Therefore, there is urgent unmet need for a more effective therapy that targets cancer cells as well as cancer stem cells. We screened for a novel compound that can target both cancer cells as well cancer stem cells and came cross Verrucarin J, a metabolite of the Myrothecium fungus family which has not been tested for its antitumor activity. We aim to determine the effects of Verrucarin J on ovarian cancer cell proliferation, cell apoptosis, DNA damage, and gene expression for CSCs. In our preliminary experiments, we treated two cisplatin-sensitive ovarian cancer cell lines (A2780 and OVCAR5) and one cisplatin-resistance (A2780/CP70) cells, and lung cancer cells (A549 and H1793) with various concentrations of Verrucarin J. After treatment of cells with Verrucarin J showed i) a highly significant inhibition of ovarian cancer cell proliferation in a dose- and time-dependent manner with an IC50 value of approximately 10 nM after 48 h of treatment for all the cell lines, ii) a significant increase in cell apoptosis, iii) significant increase in DNA damage and generation of reactive oxygen species (ROS), iv) down regulation of expression of various cancer stem cells (CSCs) markers genes, v) significant suppression of tumor growth and metastasis in nude mice, and vi) significantly inhibition of Wnt1, Notch1 and Shh signaling pathways in a dose-dependent manner.  Wnt1, Notch1 and Shh are major regulatory pathways for self-renewal and maintenance of cancer stem cells. In addition, in our study, we also showed that Verrucarin J inhibited the tumorigenic function (spheroid formation on ultra-low attachment plates) of isolated ALDH1 positive CSCs from ovarian cancer cell line A2780. Based on these results, we conclude that Verrucarin J is a highly potent anti-tumor drug and targets both cancer cells and cancer stem cells, therefore it may serve as a potential therapeutic candidate for ovarian and other cancers treatment and replace currently used chemo-therapies. This is the first report suggesting that Verrucarin J is a highly potent anticancer drug and inhibits both cancer cells and cancer stem cells. At present, our research focus is to determine: 1) efficacy of Verrucarin J on ovarian tumor growth and metastasis in PDX model generated by injecting patients ascites cancer stem cells,  2) determine the organ and tissue toxicity of Verrucarin J, and 3) molecular mechanisms (Wnt1, Notch1 and SHH) that mediate the antitumor effects of Verrucarin J. Outcome of our study will justify the initiation of phase I/phase II clinical trials to assess Verrucarin J toxicity and efficacy in advanced/recurrent ovarian cancer patients.

Securin and Cancer Stem Cells in Regulation of Tumor Growth and Progression

Some of the questions to answer in tumorigenesis is how tumor initiates, what cancer stem cells are, what the origin of cancer stem cells is, and how these cancer stem cells are involved in tumor progression and metastasis. Our search of literature resulted in number of hypothesis. Some of these include: Cancer stem cells are tumor initiating cells and are involved in metastasis of cancer; cancer stem cells develop from normal stem cells as a results of multiple mutations; and cancer stem cells are already present in tissues and organs and are under a suppressive mechanism (niche). Change in microenvironment activates the proliferation and differentiate these cells to mature cancer stem cells while maintaining their phenotype. In our recent studies, we observed that securin also known as pituitary transforming gene (PTTG) is co-expressed with known CSCs markers in normal ovary and in ovarian cancer at various stages of tumorigenesis, and ascites cells collected from patients with ovarian cancer. Presence of securing as well as CSCs were found in both ovarian surface epithelium and ovarian cortex. Co-expression of both securing and CSCs markers in normal ovary and ovarian tumor suggests the plausibility of regulation of CSCs population by securin. Securin is an oncogene which was reported to be highly expressed in almost every tumor analyzed to date. Overexpression of securin induces cellular transformation and tumor development in nude mice. In contrast, knockout of securin in ovarian tumor cell line as well as other tumors cell lines results in suppression of tumor growth and metastasis. Knockout of securin in animals results in reduction in tumor development from 80% to 30%, suggesting that securin is one of the major regulator in tumorigenesis. Based on this information we hypothesize that securin regulate the CSCs population. In our recent experiments we showed that knock out of securin in ovarian tumor cell line A2780 results in suppression of expression of cancer stem cells markers genes and inhibition of WNT1 mechanisms (a major mechanism involved in self-renewal and maintenance of CSCs population. We are very excited from our study and believe that securin may a novel marker for stem cells as well as cancer stem cells and regulates tumorigenesis by regulating CSCs population. To prove our hypothesis, we are performing several knockout experiments in vitro and in vivo to conclude the role of securin in regulation of tumorigenic pathways and CSCs population.

Representative Publications:

  1. Abdelbaset-Ismail A, Cymer M, Borkowska-Rzeszotek S, Brzeźniakiewicz-Janus K, Rameshwar P, Kakar SS, Ratajczak J, Ratajczak MZ.  Bioactive phospholipids enhance migration and adhesion of human leukemic cells by inhibiting heme oxygenase 1 (HO-1) and inducible Nitric Oxygenase Synthase (iNOS) in a p38 MAPK-dependent manner.  Stem Cell Reviews 2018; Oct 9. doi; 10.1007/512015-018-9853. Review. PMID: 30302660.
  2. Parte SC, Batra SK, Kakar SS.  Characterization of stem cell and cancer stem cell populations in ovary and ovarian tumors.  Journal of Ovarian Research 2018 Aug 18;11(1):69. PMID: 30121075. PMCID: PMC6098829.
  3. Bliss SA, Paul S, Pobiarzyn PW, Ayer S, Sinha G, Pant S, Hilton H, Sharma N, Cunha MF, Engelberth DJ, Greco SJ, Bryan M, Kucia MJ, Kakar SS, Ratajczak MZ, Rameshwar P. Evaluation of a developmental hierarchy for breast cancer cells to assess risk-based patient selection for targeted treatment.  Nature Scientific Reports 2018 Jan 10;8(1):367. PMID: 29321622. PMCID: PMC5762675.
  4. Carter K, Rameshwar P, Ratajczak MZ, Kakar SS.  Verrucarin J inhibits ovarian cancer and targets cancer stem cells.  Oncotarget 2017 Oct 6;8(54):92743-56. PMID: 29190952. PMCID: PMC5696218.
  5. Kakar SS, Parte S, Carter K, Joshua IG, Worth C, Rameshwar P, Ratajczak MZ.  Withaferin A (WFA) inhibits tumor growth and metastasis by targeting ovarian cancer stem cells.  Oncotarget 2017 Aug 10;8(43):74494-505. PMID: 29088802. PMCID: PMC5650357.
  6. Parte SC, Smolenkov A, Batra SK, Ratajczak MZ, Kakar SS.  Ovarian cancer stem cells: Unraveling a germline connection.  Stem Cells Development 2017 Dec 15;26(24):1781-803. PMID: 29078734.
  7. Schneider G, Sellers ZP, Bujko K, Kakar SS, Kucia M, Ratajczak MZ.  Novel pleiotropic effects of bioactive phospholipids in human lung cancer metastasis.  Oncotarget 2017 Apr 27;8(35):58247-63. PMID: 28938552. PMCID: PMD5601648.
  8. Kakar SS, Worth CA, Wang Z, Carter K, Ratajczak M, Gunjal P.  DOXIL when combined with Withaferin A (WFA) targets ALDH1 positive cancer stem cells in ovarian cancer.  Journal of Cancer Stem Cell Research 2016;4. pii: e1002. PMID: 27668267. PMCID: PMC5033248.
  9. Abdelbaset-Ismail A, Pedziwiatr D, Suszyńska E, Sluczanowska-Glabowska S, Schneider G, Kakar SS, Ratajczak MZ.  Vitamin D3 stimulates embryonic stem cells but inhibits migration and growth of ovarian cancer and teratocarcinoma cell lines.  Journal of Ovarian Research 2016 Apr 18;9:26. PMID: 27091127. PMCID: PMD4835879.
  10. Gunjal P, Pedziwiatr D, Ismail AA, Kakar SS, Ratajczak MZ. An emerging question about putative cancer stem cells in established cell lines-are they true stem cells or a fluctuating cell phenotype?  Journal of Cancer Stem Cell Research 2015;3. pii: e1004. PMID: 26925434. PMCID: PMC4767173.
  11. Gunjal PM, Schneider G, Ismail AA, Kakar SS, Kucia M, Ratajczak MZ.  Evidence for induction of a tumor metastasis-receptive microenvironment for ovarian cancer cells in bone marrow and other organs as an unwanted and underestimated side effect of chemotherapy/radiotherapy.  Journal of Ovarian Research 2015;8:20. PMID: 25887079. PMCID: PMC4425926.
  12. Kakar SS, Kakar C.  Generation of transgenic mouse model using PTTG as an oncogene.  Methods in Molecular Biology 2015;1267:395-411. PMID: 25636481.
  13. Mierzejewska K, Borkowska S, Suszynska E, Suszynska M, Poniewierska-Baran A, Maj M, Pedziwiatr D, Adamiak M, Abdel-Latif A, Kakar SS, Ratajczak J, Kucia M, Ratajczak MZ.  Hematopoietic stem/progenitor cells express several functional sex hormone receptors-novel evidence for a potential developmental link between hematopoiesis and primordial germ cells.  Stem Cells Development 2015 Apr 15;24(8):927-37. PMID: 25607657. PMCID: PMC4390002.
  14. Kakar SS, Ratajczak MZ, Powell KS, Moghadamfalahi M, Miller DM, Batra SK, Singh SK.  Withaferin a alone and in combination with cisplatin suppresses growth and metastasis of ovarian cancer by targeting putative cancer stem cells.  PLoS One 2014 Sep 29;9(9):e107596. PMID: 25264898. PMCID: PMC4180068.
  15. Suszynska M, Poniewierska-Baran A, Gunjal P, Ratajczak J, Marycz K, Kakar SS, Kucia M, Ratajczak MZ.  Expression of the erythropoietin receptor by germline-derived cells - further support for a potential developmental link between the germline and hematopoiesis.  Journal of Ovarian Research 2014 Jan 17;7:66. PMID: 24982693. PMCID: PMC4074848.
  16. Macha MA, Rachagani S, Pai P, Gupta S, Lydiatt WM, Smith RB, Johansson SL, Lele SM, Kakar SS, Farghaly H, Lee JH, Meza J, Ganti AK, Jain M, Batra SK.  MUC4 regulates cellular senescence in head and neck squamous cell carcinoma through p16/Rb pathway.  Oncogene 2015 Mar 26;34(13):1698-708. PMID: 24747969. PMCID: PMC4205229. Erratum: 2015 May 21;34(21):2814. Farghaly H.
  17. Fong MY, McDunn J, Kakar SS.  Metabolomic profiling of ovarian carcinomas using mass spectrometry.  Methods in Molecular Biology 2013;1049:239-53. PMID: 23913221.
  18. Fong MY, Farghaly H, Kakar SS.  Tumorigenic potential of pituitary tumor transforming gene (PTTG) in vivo investigated using a transgenic mouse model, and effects of cross breeding with p53 (+/-) transgenic mice.  BMC Cancer 2012 Nov 20;12:532. PMID: 23164239. PMCID: PMC3530432.
  19. Fong MY, Jin S, Rane M, Singh RK, Gupta R, Kakar SS.  Withaferin A synergizes the therapeutic effect of doxorubicin through ROS-mediated autophagy in ovarian cancer.  PLoS One 2012;7(7):e42265. PMID: 22860102. PMCID: PMC3408484.
  20. Shah PP, Fong MY, Kakar SS.  PTTG induces EMT through integrin αVβ3-focal adhesion kinase signaling in lung cancer cells.  Oncogene 2012 Jun 28;31(26):3124-35. PMID: 22081074. PMCID: PMC3288952.

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