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Principal Investigator: JINGFANG JU
Organization: NORTHPORT VA MEDICAL CENTER
Fiscal Year: 2023
Funding agency: Veterans Affairs
Project Summary/Abstract The goal of this application is to investigate the roles of miR-15a in colorectal
cancer and to develop novel miR-15a mimic as potential therapeutics to treat advanced metastatic colorectal
cancer in both male and female Veterans. Despite advancements in early detection and improved treatment
strategies, there are still 50,260 deaths due to colorectal cancer in the United States, and its incidence is
equally high in the Veteran population. Resistance to fluoropyrimidine-based chemotherapy is one of the major
causes for the failure of treating advanced metastatic colorectal cancer. It has been recognized recently that
epigenetic alterations play a key role in tumorigenesis and resistance to 5-fluorouracil (5-FU) based
chemotherapy. Because colorectal cancer cells are highly heterogeneous, chemotherapy can be quite effective
in eliminating most of the rapid proliferating cancer cells. However, a small population of slow proliferating
cancer stem cells are highly resistant which leads to cancer recurrence. Although the mechanism of
chemoresistance is complex and is often associated with elevated target enzyme thymidylate synthase (TS,
TYMS), recent studies from our laboratory have shown that epigenetic alterations such as changes in
expression of non-coding miRNAs are major contributors to such resistance mechanisms to 5-FU by providing
acute changes in protein synthesis at the post-transcriptional and translational levels. miRNAs are a class of
small non-coding RNAs with crucial regulatory functions. We have identified a number of miRNAs with tumor
suppressive functions in colorectal cancer. In particular, we have demonstrated that miR-15a (hsa-miR-15a-5p)
can overcome chemoresistance in colorectal cancer as a potent tumor suppressor by inhibiting the expression
of several major therapeutic target genes (BMI1, BCL2, YAP1, DCLK1) and associated pathways. More
importantly, we have recently developed a novel strategy to create modified miRNA mimics with enhanced
stability and efficacy for eliminating 5-FU resistant colon cancer stem cells while retaining target specificity.
miR-15a mimics were designed by modifying the target strand of miR-15a by replacing uracil (U) bases with 5-
FU at various locations. The rationale behind this approach is that 5-FU modification of miR-15a will enhance
stability, and also combining the power of 5-FU and multi-targeted miR-15a into one entity to create therapeutic
synergy, as miR-15a will breakdown eventually to release 5-FU. A unique feature of the 5-FU modified miR-
15a is that it can be internalized by colon cancer cells without any delivery vehicle. This represents a major
advancement and a paradigm shift in miRNA based therapeutic development. Our preliminary results show
that such modification improves the potency and stability of the miR-15a mimic and enhances its ability to
inhibit colon cancer metastasis in vivo without any observed toxicity. Specific Aim 1: We will define the direct
targets and pathways of miR-15a and miR-15a mimic in colon cancer and characterize the effects of miR-15a
mimic on apoptosis, cell cycle control, and chemoresistance in colon cancer cells and 3D organoids. Specific
Aim 2: We will investigate the toxicity, pharmacokinetics and tissue distribution of miR-15a mimic in vivo colon
cancer mouse models. Specific Aim 3: We will develop and characterize the therapeutic potential of miR-15a
mimic in metastatic colorectal cancer using in vivo colon cancer mouse models.
Terms: <3-D><3-Dimensional><3D><5-FU><5-Fluracil><5FU><Acute><Apoptosis><Apoptosis Pathway><B cell lymphoma 2><B lymphoma Mo MLV insertion><B-Cell CLL/Lymphoma 2 Gene><B-cell lymphoma/leukemia-2><BCL2><BCL2 gene><BMI1><BMI1 gene><Bcl-2><CD44><CD44 gene><Cell Cycle Control><Cell Cycle Regulation><Cell Line><CellLine><Cessation of life><Chemoresistance><Colo-rectal Cancer><Colon><Colon Cancer><Colon Carcinoma><Colorectal Cancer><Complex><Death><Development><Drug Kinetics><Drug or chemical Tissue Distribution><Early Diagnosis><Enzyme Gene><Enzymes><Epigenetic><Epigenetic Change><Epigenetic Mechanism><Epigenetic Process><Epithelial Cells><Failure><Female><Fluoro Uracil><Fluorouracil><Fluoruracil><Fluouracil><Functional RNA><Gene Action Regulation><Gene Expression Regulation><Gene Regulation><Gene Regulation Process><Generalized Growth><Genes><Goals><Growth><Hair><Human><Incidence><Laboratories><Life><Location><MDU3><Magnetic nanoparticles><Malignant Cell><Mice><Mice Mammals><Micro RNA><MicroRNAs><Modeling><Modern Man><Modification><Murine><Mus><Non-Coding><Non-Coding RNA><Non-translated RNA><Noncoding RNA><Nontranslated RNA><Oncogenesis><Organoids><PDX model><Pathway interactions><Patient derived xenograft><Patients><Pgp1><Pharmacokinetics><Play><Population><Programmed Cell Death><Proliferating><Protein Biosynthesis><QOL><Quality of life><RNA Degradation><Recurrent Cancer><Recurrent Malignant Neoplasm><Recurrent Malignant Tumor><Resistance><Ribosomal Peptide Biosynthesis><Ribosomal Protein Biosynthesis><Ribosomal Protein Synthesis><Role><Specificity><Strains Cell Lines><TMP synthetase><TYMS><TYMS gene><Therapeutic><Thymidylate Synthase><Thymidylate Synthase Gene><Thymidylate Synthetase><Tissue Distribution><Tissue Growth><Toxic effect><Toxicities><Treatment Efficacy><Tumor Suppressor Proteins><United States><Untranslated RNA><Uracil><Veterans><Weight><Woman><appetite loss><base><bases><bcl-2 Genes><cancer cell><cancer diagnosis><cancer in the colon><cancer progenitor cells><cancer recurrence><cancer stem cell><ced9 homolog><chemoresistant><chemotherapy><chemotherapy resistance><chemotherapy resistant><colo-rectal cancer metastasis><colon cancer metastasis><colorectal cancer metastasis><cultured cell line><dTMP Synthase><delivery vector><delivery vehicle><design><designing><developmental><early detection><epigenetically><fluoropyrimidine><improved><in vivo><intervention efficacy><knock-down><knockdown><lipid based nanoparticle><lipid nanoparticle><loss of function><mRNA Translation><male><malignant stem cell><men><metastatic colo-rectal><metastatic colo-rectal cancer><metastatic colo-rectal carcinoma><metastatic colon cancer><metastatic colorectal><metastatic colorectal cancer><metastatic colorectal carcinoma><miR therapy><miR-based therapeutic><miR-based therapy><miRNA><miRNA therapy><miRNA-based therapeutic><miRNA-based therapy><miRNAs><microRNA-based therapeutic><microRNA-based therapy><military veteran><mouse model><murine model><new approaches><new drug treatments><new drugs><new pharmacological therapeutic><new therapeutics><new therapy><next generation therapeutics><noncoding><novel><novel approaches><novel drug treatments><novel drugs><novel pharmaco-therapeutic><novel pharmacological therapeutic><novel strategies><novel strategy><novel therapeutics><novel therapy><oligofectamine><ontogeny><pathway><patient derived xenograft model><posttranscriptional><progenitor Cell growth><protein expression><protein synthesis><resistance mechanism><resistant><resistant mechanism><social role><stem cell growth><subcutaneous><subdermal><synergism><therapeutic agent development><therapeutic development><therapeutic efficacy><therapeutic miRNA><therapeutic miRs><therapeutic microRNA><therapeutic target><therapy efficacy><three dimensional><treatment strategy><tumor><tumor suppressor><tumorigenesis><veteran population><weights>