Grunkemeyer, J. A. | Search bioRxiv

bioRxiv2025

The human Flower isoform hFWE4 facilitates cornification in cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (cSCC) is the second most common human tumor and arises from keratinocytes that comprise the epidermis and its associated hair follicles. Remarkably, transformed keratinocytes within a cSCC retain some ability to execute the terminal differentiation program that typically generates a stratified epidermis. Instead of the polarized stratification towards the body surface seen in normal epidermis, cSCC keratinocytes differentiate concentrically inward to produce keratin pearls. It is well appreciated that cSCC differentiation status is correlated with degree of local invasion and potential for distant metastasis, with well differentiated tumors having a better prognosis. While molecular mechanisms that govern the differentiation process are incompletely understood, identifying candidate molecules associated with cSCC differentiation can provide new histologic markers for prognostic stratification. Here we demonstrate that Flower (FWE), a newly described regulator of lamellar body (LB) trafficking in normal epidermis, is specifically expressed within highly differentiated layers of cSCC. Genetic knockout of the hFWE gene dysregulates cornification and LB-related gene expression leading to abnormal keratinization patterns, while ectopic hFWE4 expression drives G1-arrest and exit from the proliferative basal keratinocyte population. Additionally, we find that poorly differentiated keratinocyte regions of human cSCC exhibit minimal FWE-positivity, while this population is readily detectable in well-differentiated regions. We propose that FWE represents a novel differentiation marker in cSCC that could be utilized for classifying differentiation status and prognostic stratifying these tumors.

cancer biology↗

bioRxiv2018

Generation of tumorigenic porcine pancreatic ductal epithelial cells: toward a large animal model of pancreatic cancer

Background. A large animal model of pancreatic cancer would permit development of diagnostic and interventional technologies not possible in murine models, and also would provide a more biologically-relevant platform for penultimate testing of novel therapies, prior to human testing. Here, we describe our initial studies in the development of an autochthonous, genetically-defined, large animal model of pancreatic cancer, using immunocompetent pigs.\n\nMethods. Primary pancreatic epithelial cells were isolated from pancreatic duct of domestic pigs; epithelial origin was confirmed with immunohistochemistry. Three transformed cell lines subsequently were generated from these primary cells using expression of oncogenic KRAS and dominant negative p53, with/without knockdown of p16 and SMAD4. We tested these cell lines using in vitro and in vivo assays of transformation and tumorigenesis.\n\nResults. The transformed cell lines outperformed the primary cells in terms proliferation, population doubling time, soft agar growth, 2D migration, and Matrigel invasion, with the greatest differences observed when all four genes (KRAS, p53, p16, and SMAD4) were targeted. All three transformed cell lines grew tumors when injected subcutaneously in nude mice, demonstrating undifferentiated morphology, mild desmoplasia, and staining for both epithelial and mesenchymal markers. Injection into the pancreas of nude mice resulted in distant metastases, particularly when all four genes were targeted.\n\nConclusions. Tumorigenic porcine pancreatic cell lines were generated. Inclusion of four genetic \"hits\" (KRAS, p53, p16, and SMAD4) appeared to produce the best results in our in vitro and in vivo assays. The next step will be to perform autologous or syngeneic implantation of these cell lines into the pancreas of immunocompetent pigs. We believe that the resultant large animal model of pancreatic cancer could supplement existing murine models, thus improving preclinical research on diagnostic, interventional, and therapeutic technologies.

cancer biology↗