The cylindromatosis (CYLD) gene and head and neck tumorigenesis.

Germline CYLD mutation is associated with the development of a rare inheritable syndrome, called the CYLD cutaneous syndrome. Patients with this syndrome are distinctly presented with multiple tumors in the head and neck region, which can grow in size and number over time. Some of these benign head and neck tumors can turn into malignancies in some individuals. CYLD has been identified to be the only tumor suppressor gene reported to be associated with this syndrome thus far. Here, we summarize all reported CYLD germline mutations associated with this syndrome, as well as the reported paired somatic CYLD mutations of the developed tumors. Interestingly, whole-exome sequencing (WES) studies of multiple cancer types also revealed CYLD mutations in many human malignancies, including head and neck cancers and several epithelial cancers. Currently, the role of CYLD mutations in head and neck carcinogenesis and other cancers is poorly defined. We hope that this timely review of recent findings on CYLD genetics and animal models for oncogenesis can provide important insights into the mechanism of head and neck tumorigenesis.

A Pan-Cancer Review of ALK Mutations: Implications for Carcinogenesis and Therapy.

The anaplastic lymphoma kinase (ALK) is a druggable target for cancer therapy. By and large, the oncogenic activation of ALK in human tumors is known to occur by gene rearrangement (e.g. EML4-ALK, NMP-ALK, etc.). Clinical use of ALK inhibitors for "ALK-rearranged" lung cancers has remarkably improved patient survival. To date, much has been known about ALK gene rearrangement in human carcinogenesis and its drug sensitivity relationship. However, emerging genomic data from the Cancer Genome Atlas (TCGA, USA) are now revealing common ALK point mutations (~3.06%) in various cancer types other than lung cancer. Importantly, several recent studies have demonstrated that ALK point mutations, independent of ALK-gene rearrangement, can be oncogenic. Thus, ALK mutations can be pathogenically and perhaps therapeutically important for various cancer types. Here, we summarized the latest ALK mutation frequencies and mutation patterns across 17 human cancer types stemming from TCGA. Unlike many other oncogenes with high frequency of hotspot mutations, ALK point mutations tend to span along the entire gene. Up till now, several recurrent mutations (G263, R401, R551, P968 and E1242) and mutation-rich cluster regions have been identified, but their functional effects remain unknown. We also conducted a comprehensive review of all ALK-mutated human cancer cell lines (from the Cell Line Encyclopedia (CCLE) and the NCI-60 panel), which can be used as model systems for ALK mutation biology and drug screening studies. Lastly, we summarized both the preclinical and clinical findings of ALK mutations on carcinogenesis and drug sensitivity, which may provide important insight into new treatment strategies and prompt future ALK mutation studies in various cancer types.