Sita Withers

Sita Withers

Assistant Professor of Medical Oncology

Department of Veterinary Clinical Sciences

LSU School of Veterinary Medicine
Louisiana State University
Baton Rouge, LA 70803




PhD, University of California, Davis, 2018

BVSc, Melbourne University (Australia), 2008


Diplomate, American College of Veterinary Internal Medicine (Oncology)

Research Interest

Comparative cancer immunology; tumor microenvironment; metastasis

Teaching Interest

Clinical instruction; Communication

Awards & Honors

2021, Dean's Teacher Merit Honor Roll (Years II and IV)

2020, Dean's Teacher Merit Honor Roll (Years I and IV)

2008, Graduated with honours

Select Publications

Costa VR, Soileau AM, Liu CC, Moeller CE, Carossino M, Langohr IM, Withers SS. Exploring the association of intratumoral immune cell infiltrates with histopathologic grade in canine mast cell tumors. In press: To appear in Research in Veterinary Science.

Groves PK, Liu CC, Geels OR, Withers SS. The use of 'trend' statements in veterinary oncology literature. Vet Comp Oncol. 2022 Mar 11. doi: 10.1111/vco.12811. 

Hu T, Dehghanpir S, Sasaki E, Costa V, Pucheu-Haston CM, Del Piero F, Withers SS. Pathology in Practice: Malignant Trichoepithelioma (Matrical Carcinoma) in a Dog. In press: To appear in Journal of the American Veterinary Medical Association.    

Bauman A, Moeller C, Soileau A, Goodermuth C, Costa V, Schaumburg J, Pucheu-Haston CM, Welborn N, Dehghanpir S, Mitchell M, Withers SS. Canine Memory T-Cell Subsets in Health and Disease. Veterinary Immunology and Immunopathology. 2022; 246: 110401. doi: 10.1016/j.vetimm.2022.110401.

Dehghanpir SD, Boudreaux B, Withers SS, Izquierdo A, Sasaki E, Del Piero F, Braden M, Mitchell MA; Chemotherapy-responsive acute myeloid leukemia in a veiled chameleon (Chamaeleo Calyptratus). Journal of Herpetological Medicine and Surgery. 2021; 31(4): 257–263. doi: 

Singh SS, Mattheolabakis G, Gu X, Withers SS, Dahal A, Jois S. A grafted peptidomimetic for egfr heterodimerization inhibition: implications in nsclc models. European Journal of Medicinal Chemistry. 2021; 216. doi:  

Sparger EE, Chang H, Chin N, Rebhun RB, Withers SS, Kieu H, Canter RJ, Monjazeb AM, Kent MS. T cell immune profiles of blood and tumor in dogs diagnosed with malignant melanoma. Frontiers In Veterinary Science. 2021; 8. doi:   

Choi JW, Withers SS, Chang H, Spanier JA, De La Trinidad VL, Panesar H, Fife BT, Sciammas R, Sparger EE, Moore PF, Kent MS, Rebhun RB, McSorley SJ. Development of canine PD-1/PD-L1 specific monoclonal antibodies and amplification of canine T cell function. PLoS One. 2020 Jul 2;15(7).

Withers, SS, Sparger, EE, Boudreaux, B, & Mason, NJ. Utilizing Microbes to Treat Naturally Occurring Cancer in Veterinary Species. Current Clinical Microbiology Reports, 2019, 6(4), 200-212.

Withers SS, York D, Choi JW, Woolard KD, Laufer-Amorim R, Sparger EE, Burton JH, McSorley SJ, Monjazeb AM, Murphy WJ, Canter RJ, Rebhun RB. Metastatic immune infiltrates correlate with those of the primary tumour in canine osteosarcoma. Vet Comp Oncol. 2019 Sep;17(3):242-252.

Wang Z, Aguilar EG, Luna JI, Dunai C, Khuat LT, Le CT, Mirsoian A, Minnar CM, Stoffel KM, Sturgill IR, Grossenbacher SK, Withers SS, Rebhun RB, Hartigan-O'Connor DJ, Méndez-Lagares G, Tarantal AF, Isseroff RR, Griffith TS, Schalper KA, Merleev A, Saha A, Maverakis E, Kelly K, Aljumaily R, Ibrahimi S, Mukherjee S, Machiorlatti M, Vesely SK, Longo DL, Blazar BR, Canter RJ, Murphy WJ, Monjazeb AM. Paradoxical effects of obesity on T cell function during tumor progression and PD-1 checkpoint blockade. Nat Med. 2019 Jan;25(1):141-151.

Grant Funding

Center for Preclinical Disease Research Project 1- "Strategic inhibition of EGFR-family signaling using novel peptidomimetic inhibitors of HER-2 for the treatment of osteosarcoma", NIH COBRE, $669,105.00

Repurposing drugs to modulate myeloid-derived suppressor cells (MDSCs) in canine soft tissue sarcomas, American Kennel Club- Canine Health Foundation, $13,782.00

Exploring abscopal effects in canine nasal tumors via fine needle aspirate of draining lymph nodes, VCS CORP, $3,950.00

Uncovering the ability of chemotherapy-resistant canine osteosarcoma cells to modulate the immune microenvironment via IL-34 production , VCS CORP, $3,998.00

Center for Translational Viral Oncology Pilot- "Utilization of naturally-occurring canine osteosarcoma to develop virus-based combination immunotherapy strategies that exploit defects in STING signaling", NIH COBRE, $58,399.00

Prospective evaluation of the effect of vincristine alone on tumor burden and circulating myeloid-derived suppressor cells (MDSCs) in dogs with naïve high-grade multicentric lymphoma, VCS CORP, $4,000.00

Verification of phenotypic markers identifying T-lymphocyte memory subsets in dogs, VCS CORP, $4,000.00

Characterizing The Effects of STING Deficiency in Osteosarcoma Cells on DNA Damage-Induced Inflammation, SVM CORP, $10,000.00

Design, synthesis and evaluation of grafted peptides/peptidomimetics for the inhibition of protein-protein interactions of EGFRs in osteosarcoma, Louisiana Biomedical Research Network - Graduate student summer research program, $8,000.00