LOX-IMV1 Xenograft Model

LOX-IMV1 Xenograft Model

Melanoma is a subtype of cancer that affects cells that produce pigment in the skin (melanocytes). This is why typically this cancer type involves changes in the color of the skin along with skin growths. UV (ultraviolet) radiation (sun, tanning devices) are directly linked to causing melanoma skin cancer. A rare type of melanoma, amelanotic melanoma, are growths that are incapable of producing pigment and therefore have the appearance of reddish pink growths or lesions. Most people are treated successfully because they are diagnosed at an early stage. However, amelanotic melanoma fatality rates are higher as they are typically undiagnosed for longer and then diagnosed at a later stage. The LOX-1MV1 cell line was established from an axillary lymph node (metastatic site) of a 58 year old male patient with amelanotic melanoma. Since then LOX-1MV1 cells have been used in various melanoma research studies. In 2012, Karmali et al. (Journal of Solid Tumors) used LOX IMVI xenografts in order to characterize the combination treatment of carboxyamidotriazole-orotate (CTO), a compound with calcium channel-mediated inhibition of proliferation and metastasis, with temozolomide, an established anticancer drug. Data demonstrated that CTO enhanced sensitivity and efficacy of tumors to temozolomide, effectively reducing dose requirements, drug resistance while increasing temozolomide toxicity.  A 2005 Molecular Therapy article (Goldsmith et al.) used xenograft models of LOX-1MV1 to investigate the effect of FK228, a histone deacetylase inhibitor, on adenovirus gene therapy. The group monitored coxsackie adenovirus receptor (CAR) and αv-integrin levels and concluded that FK228 combination therapy in vivo induces increases in adenovirus transgene expression thereby increasing the efficacy of this established adenovirus gene therapy. Finally, the 1995 Cancer Research article (Plowman et al.) used melanoma xenograft models including LOX-1MV1 to confirm the anticancer effects of DX-52,-1, an analoge of KW2152 (Quinocarmycin monicitrate). Results demonstrated that prolonged treatment resulted in a decrease in tumor cell burden as well as tumor regressions, suggesting successful tumor growth inhibition. This data was used to support the use of DX-52-1 in NCI preclinical development. The LOX-1MV1 cell line is used to create the CDX (Cell Line Derived Xenograft) LOX-1MV1 xenograft mouse model. The LOX-1MV1 xenograft model has been used to identify potential antimelanoma therapies.

Basic Study Design

  1. LOX-1MV1 cells are maintained in exponential growth phase under aseptic conditions.
  2. Cells are trypsinized and cell count viability is determined using a trypan blue exclusion assay (98% of cell viability is required).  LOX-1MV1 cell suspension is adjusted to appropriate density.
  3. Each mouse is singly subcutaneously injected into the right flank with 106 cells in 100 µL of a Matrigel- LOX-1MV1 cell suspension.
  4. The injection sites are palpated up to three times weekly until tumors are established to an average size of 50-150 mm3 as measured via digital calipers.
  5. Animals are randomized into treatment groups. Administration of test compound is performed according to the pre-established treatment schedule.
  6. Mice weights are measured and recorded 3 times weekly; tumors are measured and recorded daily.
  7. End of study is reached when tumor size reaches 2,000 mm3 or the predetermined size limit per approved IACUC protocol.
  8. Final necropsy and tissue collections are performed for appropriate downstream analysis. Tumors are excised, weighed and documented by digital imaging. Tumors and tissues can be stabilized in RNAlater, snap frozen in liquid nitrogen (LN2) or prepared for histology.