Funded by 2018 Kay Yow Cancer Fund Final Four Research Award
Endometrial cancer (EC) is the most common gynecologic cancer in the developed world, and the 4th most common cancer in women in the United States, with over 60,000 diagnoses expected in 2017. While most women diagnosed with EC have a favorable prognosis following hysterectomy, a subset have poor outcome despite what is thought to be a “low risk” disease. Identification of factors that predict poor outcome have been elusive to date. With the expansion of the knowledge of the genetic basis of cancer, we and others have begun exploring “molecular” prognostic factors – the genetic signature of the cancer that may predict outcome. This proposal aims to study a large sample of women with EC, testing their cancer for its genetic signature, and correlating this signature with clinical outcome. Identification of the signature that predicts outcome will allow for a more refined approach to identification of women who would benefit from additional therapy following hysterectomy to improve survival. This will be done in a process that is able to be replicated in most hospital laboratories, allowing this project to be relevant and accessible in all communities in which women are diagnosed with this disease.
Nearly 1 million individuals in the United States have inherited mutations in the BRCA1 or BRCA2cancer susceptibility genes and have a very high risk for several cancers, including breast and ovarian cancer in women. Although clinical screening in individuals with known genetic risk can help identify cancers early when they are potentially more curable, this approach is imperfect. Therefore, there is an urgent need to identify ways to better detect and treat cancers in this high risk population. Like most cancers, those that arise in BRCA1/2 mutation carriers have an unstable genome.Manytypes of genomic instability are initiated by DNA breaks, particularly in BRCA1/2 carriers, as these genes are normally involved in DNA repair. Understanding how DNA breaks arise and are repaired is thus critical for understanding how cancer arises, and for developing therapies that specifically kill cancer cells or prevent their development.Our work indicates that when genomic DNA is transcribed into RNA, the RNAand DNA may get tangled, creating RNA-DNA hybrid molecules, or R-loops, that cause the DNA to be broken. BRCA1 and BRCA2 proteinshelp prevent R-loop formation. This raises the possibility that BRCA1 and BRCA2 prevent breast cancer development by regulating the formation of R-loops. In this proposal, we will explore what BRCA1 and BRCA2 do at R-loops, determine where R-loops form in cells without these genes and explore the possibility of using RNA-DNA hybrids as early, sensitive markers of cancer to improve detection and treatment.
Funded in partnership with the Buster and Kristen Posey Fund with support from Apple Gold Group
Despite numerous clinical trials for children with high grade glioma, including diffuse pontine glioma, either at initial diagnosis or recurrence, over the past 4 decades, there has been little improvement in patient outcome. In contrast, in the past few years major advances have been made in understanding the molecular underpinnings of these tumors. Specific, gene mutations in the genes encoding the histone H3.3 (H3F3A) and H3.1 (HIST1H3B, HIST1H3C) variants, along with BRAF V600E, mark distinct subgroups of disease in children and young adults. This proposal will combine our innovations in the clinic using the genetically recombinant poliovirus PVSRIPO with targeting technology aimed at these exploiting these mutations as targets.
In the currently accruing adult trials and the planned initial pediatric high grade glioma trial, PVSRIPO is administered by delivery into the tumor, via a surgical approach. In many pediatric glioma patients, diffuse infiltrating growth or location (e.g. diffuse intrinsic pontine gliomas; DIPG) precludes such intra-tumoral administration.
We plan to test a modified PVSRIPO technology for peripheral immunization with tumor-specific targets to create a viable alternative in pediatric brain tumors. We have recently developed robust technology to modify PVSRIPO for use as an immunization vector and have demonstrated PVSRIPO vectors do not require intratumoral administration and are able to generate tumor antigen-specific immune responses. These discoveries will enable us to develop virus based vaccination strategies for pediatric brain tumor patients where tumor-specific antigens are homogeneously expressed.
The human immune response can not only eliminate infections caused by viruses, bacteria and fungi, but can also kill cancer cells. Immunity is mediated by white blood cells. Among the different types of white blood cells, killer T cells can eliminate cancer cells, whereas regulatory T cells and some types of macrophages can block anti-cancer immunity and actually support cancer growth. The ability of killer T cells to eradicate cancer cells can be blocked by “immune checkpoint” proteins within the tumor microenvironment. Drugs have been developed to inhibit immune checkpoints (CTLA-4, PD-1 and PD-L1); thereby releasing the “brakes” on killer T cells to fight cancer. Using a combination of immune checkpoint inhibitors more than half of patients with widespread melanoma can experience long-term remission and possible cure.
Unfortunately, immune checkpoint inhibitors have been largely unsuccessful in patients with advanced prostate cancer. To better understand why they are not more effective, Dr. Subudhi’s team has evaluated the immune profile of primary and metastatic prostate cancers. They have found that the bone metastatic site is a highly immunosuppressive environment. This likely accounts for the poor clinical responses seen in patients with metastatic prostate cancer treated with a single agent immune checkpoint inhibitor. The overall goal of Dr. Subudhi’s clinical trials program is to improve survival in patients with advanced prostate cancer by enhancing T cell functions while eradicating the immunosuppressive cells within the cancer. Ultimately, his aim is to make immunotherapies in prostate cancer as effective as they are in melanoma.
Unlike childhood leukemia that has a 90% cure rate, outcomes for adult patients with acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) remain poor. With modern chemotherapy regimens, complete remission rates are 60-70%, yet long term cure rates remain dismal at 15-25%. Prognosis is even worse in older patients and/or those with high risk features, with remission rates of only ~35-50% and cure rates less than 10%. Efforts to improve both the remission rate and the durability of remission are paramount.
Dr. DiNardo’s team focuses on mutations in the genes IDH1 and IDH2, which occur in ~20% of patients with AML and occur more frequently in older patients. In her clinical trials, she has tested targeted drugs that inhibit these two mutated proteins (IDH1 and IDH2) and can lead to dramatic clinical responses. These novel drugs can be taken by mouth, are well-tolerated and promise to improve the survival of patients whose leukemic cells bear these mutations. The use of these drugs that can be taken by mouth, alone and in combination with other leukemia-directed therapies, will permit patients to be treated at home with less frequent trips to MD Anderson. She will carry out not just a single trial, but a program of multiple trials to have a major impact on the lives of patients whose cancers have IDH1 and ID2 mutations. Dr. DiNardo is also striving to make screening for multiple mutated genes the standard of care for patients with MDS and AML, which is not often performed in the community, in order to optimize treatment and accelerate best practices for older adult patients with AML.
Funding from the V Foundation was used to expand Miami Cancer Institute’s services available to breast cancer patients, particularly access to breast cancer clinical trials. The major clinical services which have been funded with the V Foundation grant award include cancer genomic profiling for twenty eight (28) women. Each participant is enrolled into MSK-12-245 (NCT # NCT01775072, see enclosed ClinicalTrials.gov description) and receives a personalized genomic profile of their specific breast cancer. These profiles help to guide clinicians with matching these women to precision therapy treatments and available clinical trials which are specific to their individual tumor mutations.
V Scholar Plus Award – extended funding for exceptional V Scholars
Neuroblastoma, an embryonal tumor that arises in the peripheral sympathetic nervous system (PSNS), accounts for ~12% of cancer-related deaths in childhood. About half of all patients, especially those over 18 months of age with amplified copies of the MYCN oncogene, present with evidence of widespread metastasis at diagnosis and have a very high risk of treatment failure and death despite receiving greatly intensified chemotherapy. Attempts to improve the treatment of metastatic neuroblastoma have been slowed by the lack of a full understanding of the multistep cellular and molecular pathogenesis of this complex tumor. Recently, we developed a novel zebrafish model of neuroblastoma metastasis by overexpressing human MYCN oncogene, which is amplified in 20% of neuroblastoma cases, and knocking out gas7 gene, which is deleted in a subset of high-risk neuroblastoma patients. This zebrafish model affords unique opportunities to study the molecular basis of neuroblastoma metastasis in vivo and to identify novel genes and pathways that cooperate with MYCN overexpression or GAS7 loss to promote this fatal stage of disease development. This research approach is expected to reveal novel molecular targets that can be exploited therapeutically. To achieve this goal, we propose to establish reliable in vivo zebrafish models of the aberrant genes and pathways that contribute to neuroblastoma metastasis. In the near future, these models will be used to screen for effective small molecule inhibitors that block specific steps in metastasis with only minimal toxicity to normal tissues, and thus would be assigned high priority as candidate therapeutic agents.
One of the greatest challenges in cancer treatment is that response to standard chemotherapy is frequently incomplete and fraught with adverse events. Current treatments are often ineffective because they function as a “one-size-fits-all” approach to a very diverse disease. This lack of success is magnified in triple negative breast cancer (TNBC), whose large and diverse group of subtypes greatly increases difficulty in treating a disease that makes up 15% of all breast cancers and disproportionately affects African American and Hispanic women. The goal of our project is to address these challenges by identifying and characterizing specific tumor vulnerabilities in TNBC to pave the way for novel combined chemotherapeutic treatments. By screening through each gene in the genome, we have found that TNBC cancers rely on a protein called SIK2 for their survival. We are working to understand why SIK2 is essential and to use inhibitors of SIK2 function to reduce TNBC tumor survival.
Funded in partnership with the Lung Cancer Initiative of North Carolina, utilizing Stuart Scott Memorial Cancer Fund matching funds and the Richard Jones Fund for lung cancer
Lung cancer remains a major cause of cancer mortality worldwide, and in 2017, 155,870 people are expected to die from lung cancer in US. African Americans have the highest lung cancer incidence and lung cancer-related death rate and develop the disease at an earlier age compared to other racial groups. African Americans also have poorer survival, because of limited access to lung cancer screening, adequate healthcare, and appropriate therapeutic interventions. Etiology studies suggest that such a disparity in lung cancer may be due to genetic susceptibility, in addition to environmental exposures to cigarette smoking, radon, asbestos, and arsenic. Recently, we identified a novel gene, DCAF4, through a large-scale meta-analysis in Caucasian populations, which is likely to be involved in cell-cycle control and DNA damage response that is relevant to African Americans as well. Our hypotheses are that dysfunctional DCAF4 impacts cancer initiation and progression by altering multiple cellular processes and that DCAF4 functional variants alter gene expression and tumor cell phenotypes, which may explain racial disparity in lung cancer. Therefore, we proposed to study the functions of this gene and its risk-associated genetic variants on cellular phenotypes in lung cancer cells, animals and human clinical samples of lung cancer. We will test the hypotheses that dysfunctional DCAF4 impacts cancer initiation and progression by altering multiple cellular processes and that DCAF4 functional variants alter gene expression and tumor cell phenotypes. By including clinical samples from both Caucasians and African Americans, we hope to identify genetic markers for disparity in lung cancer.
V Scholar Plus Award – extended funding for exceptional V Scholars
Estrogen receptor positive (ER+) metastatic breast cancer (MBC) remains the most common cause of breast cancer death. Though we have made many advances in the treatment of ER+ MBC, patients invariably develop resistance to therapies. The mechanisms of resistance are not well known. In order to improve survival for patients with ER+ MBC, it is critical to develop an understanding of this resistance.
We recently found that in 7% of metastatic tumors from patients with resistant ER+ MBC, a gene called the retinoblastoma tumor suppressor (Rb) had been deleted. Loss of the Rb gene resulted in resistance to multiple agents used for ER+ MBC. ER+ MBC that lacks Rb likely represents a growing subset of patients in whom standard therapies do not work and in whom we do not know the optimal therapies. Therefore, it is critical to develop novel approaches to treating this subtype of ER+ MBC.
The goal of this research is to better understand Rb loss in ER+ MBC and identify new therapeutic strategies. To do this, we will utilize cell line models we have generated that approximate ER+ MBC that has lost the Rb gene. We will characterize these cell lines to identify how they become resistant to therapies, and identify novel therapeutic targets to prevent or overcome this resistance. At the completion of the project, our results should enable the development of clinical biomarkers of response and resistance for patients with ER+ MBC, and, ultimately, the design of clinical trials of therapeutic approaches and rational drug combinations.
