To achieve in situ tumor antigen uptake and presentation, intratumoral administration of ex vivo-generated, genemodified murine bone marrow-derived dendritic cells (DC) was used in a murine lung cancer model. To attract mature host DC and activated T cells at the tumor site, the DC were transduced with an adenoviral vector expressing secondary lymphoid tissue chemokine (CCL21/SLC). Sixty percent of the mice treated with 10 6 DC-AdCCL21 intratumorally (7-10 ng/ml/10 6 cells/24 h of CCL21) at weekly intervals for 3 weeks showed complete tumor eradication, whereas only 25% of mice had complete resolution of tumors when mice were treated with fibroblasts expressing CCL21. In contrast only 12% of the mice treated with unmodified or control vector modified DC (DC-AdCV) showed complete tumor eradication. DC-AdCCL21 administration led to increases in the CD4 ؉ , CD8 ؉ , and CD3 ؉ CXCR3 ؉ T cells, as well as DC expressing CD11c ؉ DEC205 ؉ . CD4 ؉ CD25 ؉ T-regulatory cells infiltrating the tumors were markedly reduced after DC-AdCCL21 therapy. The tumor site cellular infiltrates were accompanied by the enhanced elaboration of granulocyte macrophage colony-stimulating factor, IFN-␥, MIG/CXCL9, IP-10/CXCL10, and interleukin 12, but decreases in the immunosuppressive mediators transforming growth factor ␤ and prostaglandin E 2 . DC-AdCCL21-treated tumor-bearing mice showed enhanced frequency of tumor-specific T lymphocytes secreting IFN-␥, and tumor protective immunity was induced after DC-AdCCL21 therapy. In vivo depletion of IP-10/CXCL10, MIG/CXCL9, or IFN-␥ significantly reduced the antitumor efficacy of DCAdCCL21. These findings provide a strong rationale for the evaluation of DC-AdCCL21 in cancer immunotherapy.

No abstract

Cytoskeleton proteins have been long recognized as structural proteins that provide the necessary mechanical architecture for cell development and tissue homeostasis. With the completion of the cancer genome project, scientists were surprised to learn that huge numbers of mutated genes are annotated as cytoskeletal or associated proteins. Although most of these mutations are considered as passenger mutations during cancer development and evolution, some genes show high mutation rates that can even determine clinical outcomes. In addition, (phospho)proteomics study confirms that many cytoskeleton-associated proteins, e.g., β-catenin, PIK3CA, and MB21D2, are important signaling mediators, further suggesting their biofunctional roles in cancer development. With emerging evidence to indicate the involvement of mechanotransduction in stemness formation and cell differentiation, mutations in these key cytoskeleton components may change the physical/mechanical properties of the cells and determine the cell fate during cancer development. In particular, tumor microenvironment remodeling triggered by such alterations has been known to play important roles in autophagy, metabolism, cancer dormancy, and immune evasion. In this review paper, we will highlight the current understanding of how aberrant cytoskeleton networks affect cancer behaviors and cellular functions through mechanotransduction.

Keratin intermediate filament is one major cytoskeleton architecture in epithelial cells, providing necessary mechanical support to maintain cell shape and tissue integrity. In a previous study, we discovered the existence of a novel K6-K14 keratin fusion variant (K6-K14/V7) in oral squamous cell carcinoma (OSCC) cells which can promote cancer stemness and aggressiveness. However, the underlying mechanism remains to be elucidated. Here, we report that overexpression of K6-K14/V7 in OSCC cells can influence the mechanical properties of the cells, leading to cell protrusion and enhanced extracellular vesicle (EV) secretion. Consequently, the expression levels of inflammatory cytokines (e.g. IL-6, TGF-[[Unsupported Character - Symbol Font β]]) in the culture medium can be also increased. Normal oral fibroblast cells co-cultured with K6-K14/V7-expressing OSCC cells can be converted into a pro-inflammatory type of cancer-associated fibroblasts (iCAFs). Those findings suggest the ability of K6-K14/V7-expressing OSCC cells in remodeling tumor microenvironment. In this study, we will discuss how K6-K14/V7-expressing OSCC cells educate iCAFs to promote cancer cell migration and invasion via intercellular communication by EVs. The key signaling cascades and the associated regulatory networks will be also discussed. Our study, therefore, uncovers the pro-tumorigenic functionality of K6-K14/V7 by creating an inflammatory tumor microenvironment. Citation Format: Brian Yu-Ting Kuo, Yen-Ting Lin, Senthilkumar Ravichandran, Jim Jinn-Chyuan Sheu. K6-K14 keratin fusion variant (K6-K14/V7) in OSCC cells promotes tumor microenvironment remodeling through activating inflammatory CAFs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6101.