Tumor MK2 transcript levels are associated with improved response to chemotherapy and patient survival in non-small cell lung cancer.

Non-small cell lung cancers (NSCLCs) demonstrate intrinsic resistance to cell death, even after chemotherapy. Previous work suggested defective nuclear translocation of active caspase-3 in observed resistance to cell death. We have identified mitogen-activated protein kinase-activated protein kinase 2 (MK2; encoded by the gene MAPKAPK2) is required for caspase-3 nuclear translocation in the execution of apoptosis in endothelial cells. The objective was to determine MK2 expression in NSCLCs and the association between MK2 and clinical outcomes in patients with NSCLC. Clinical and MK2 mRNA data were extracted from two demographically distinct NSCLC clinical cohorts, North American (The Cancer Genome Atlas, TCGA) and East Asian (EA). Tumor responses following first round of chemotherapy were dichotomized as clinical response (complete response, partial response, and stable disease) or progression of disease. Multivariable survival analyses were performed using Cox proportional hazard ratios and Kaplan-Meier curves. NSCLC exhibited lower MK2 expression than SCLC cell lines. In patients, lower tumor MK2 transcript levels were observed in those presenting with late-stage NSCLC. Higher MK2 expression was associated with clinical response following initial chemotherapy and independently associated with improved 2-yr survival in two distinct cohorts, 0.52 (0.28-0.98) and 0.1 (0.01-0.81), TCGA and EA, respectively, even after adjusting for common oncogenic driver mutations. Survival benefit of higher MK2 expression was unique to lung adenocarcinoma when comparing across various cancers. This study implicates MK2 in apoptosis resistance in NSCLC and suggests prognostic value of MK2 transcript levels in patients with lung adenocarcinoma.

MK2 nonenzymatically promotes nuclear translocation of caspase-3 and resultant apoptosis.

We have previously identified mitogen-activated protein kinase-activated protein kinase 2 (MK2) is required for caspase-3 nuclear translocation in the execution of apoptosis; however, little is known of the underlying mechanisms. Therefore, we sought to determine the role of kinase and nonkinase functions of MK2 in promoting nuclear translocation of caspase-3. We identified two non-small cell lung cancer cell lines for use in these experiments based on low MK2 expression. Wild-type, enzymatic and cellular localization mutant MK2 constructs were expressed using adenoviral infection. Cell death was evaluated by flow cytometry. In addition, cell lysates were harvested for protein analyses. Phosphorylation of caspase-3 was determined using two-dimensional gel electrophoresis followed by immunoblotting and in vitro kinase assay. Association between MK2 and caspase-3 was evaluated using proximity-based biotin ligation assays and co-immunoprecipitation. Overexpression of MK2 resulted in nuclear translocation of caspase-3 and caspase-3-mediated apoptosis. MK2 directly phosphorylates caspase-3; however, phosphorylation status of caspase-3 or MK2-dependent phosphorylation of caspase-3 did not alter caspase-3 activity. The enzymatic function of MK2 was dispensable in nuclear translocation of caspase-3. MK2 and caspase-3 associated together and a nonenzymatic function of MK2, chaperoned nuclear trafficking, is required for caspase-3-mediated apoptosis. Taken together, our results demonstrate a nonenzymatic role for MK2 in the nuclear translocation of caspase-3. Furthermore, MK2 may function as a molecular switch in regulating the transition between the cytosolic and nuclear functions of caspase-3.

Performance of AmpFire HPV assay on neck cervical lymph node aspirate and oropharyngeal samples.

Early determination of high-risk human papillomaviruses causing oropharyngeal squamous cell carcinomas (OPSCC) may influence treatment. The objectives were to evaluate the performance of a new rapid isothermal nucleic acid amplification point of care HPV test (AmpFire HPV) on fine needle neck aspirates (FNA) of cervical lymph nodes and oropharyngeal swabs and saliva (OPS) which had been previously tested by the cobas HPV assay. The comparison was performed on 56 FNA and 81 OPS. The two assays showed strong agreement (94.6 %, K = 0.88) on FNA and fair agreement (65.4 %, K = 0.34) on OPS. AmpFire HPV performed on FNA demonstrated a sensitivity of 76.7 % and specificity of 81.8 % for the prediction of p16 antigens in OPSCC with results available in 1.5 h.

Treatment of first-void urine with Aptima Transfer Solution increases detection of high-risk HPV E6/E7 mRNA.

Because of its non-invasive nature urine testing may enable increased screening for HPV in women who avoid cervical sampling. Comparisons have shown fewer HPV positives in urine. The objectives were to compare first-void urine (FVU) treated with proteinase K (PK) to untreated FVU and cervical samples collected from women attending a colposcopy clinic using an Aptima HPV mRNA assay, and comparing the HPV rates to cytology and pathology results. Female FVU (n = 433) was treated with Aptima Transfer Solution (ATS) containing PK within 24 h or after months of storage. Untreated female FVU samples were HPV-positive in 20.8-27.6% compared to 34.4-45.6% of ATS-treated FVU and 44.9-48.4% of PreservCyt samples. Good overall agreement for HR-HPV detection between ATS-FVU and PreservCyt was observed (81.1%; k 0.63). Validation of ATS treatment was performed on 356 male FVU, detecting 6.7% HPV positive compared to 3.4% of untreated samples (p = 0.059). Although HPV presence in ATS FVU and PreservCyt samples were similar, significantly more women with abnormal cervical cytology and histopathology were HPV-positive in cervical specimens than in ATS-treated FVU.