Disease relevance of CCNL1

• Cyclin L1 (CCNL1) gene alterations in human head and neck squamous cell carcinoma [1].
• Performing multivariate logistic regression analysis, a significant association of CCNL1 gains and the presence of lymph node metastases was found, which was independent of anatomical site and T-stage of the primary tumour (P=0.049) [2].
• Thus, we propose cyclin L as a candidate oncogene in head and neck cancer [3].

High impact information on CCNL1

• Human cyclin L2 shares significant homology to cyclin L1, K, T1, T2, and C, which are involved in transcriptional regulation via phosphorylation of the C-terminal domain of RNA polymerase II [4].
• We report the cDNA cloning and functional characterization of human cyclin L, a novel cyclin related to the C-type cyclins that are involved in regulation of RNA polymerase II (pol II) transcription [5].
• Significantly, the IC(50) for splicing inhibition by p21 is similar to the IC(50) for inhibition of the cyclin L-associated kinase activity [5].
• Cyclin L antibody inhibits the second step of RNA splicing in vitro, and recombinant cyclin L protein stimulates splicing under suboptimal conditions [5].
• Cyclin L is an RS domain protein involved in pre-mRNA splicing [5].

Biological context of CCNL1

• We evaluated the expression and amplification of cyclin L1 (CCNL1) gene, a potential oncogene localised in the commonly amplified 3q25-28 region, in human head and neck squamous cell carcinomas (HNSCCs) [1].
• Recently, we reported that CDK12 interacts with L-type cyclins and is involved in alternative splicing regulation [H.-H. Chen, Y.-C. Wang, M.-J. Fann, Identification and characterization of the CDK12/Cyclin L1 complex involved in alternative splicing regulation, Mol. Cel. Biol. 26 (2006) 2736-2745] [6].

References