ERK3 and DGKζ interact to modulate cell motility in lung cancer cells.

Extracellular signal-regulated kinase 3 (ERK3) promotes cell migration and tumor metastasis in multiple cancer types, including lung cancer. The extracellular-regulated kinase 3 protein has a unique structure. In addition to the N-terminal kinase domain, ERK3 includes a central conserved in extracellular-regulated kinase 3 and ERK4 (C34) domain and an extended C-terminus. However, relatively little is known regarding the role(s) of the C34 domain. A yeast two-hybrid assay using extracellular-regulated kinase 3 as bait identified diacylglycerol kinase ζ (DGKζ) as a binding partner. DGKζ was shown to promote migration and invasion in some cancer cell types, but its role in lung cancer cells is yet to be described. The interaction of extracellular-regulated kinase 3 and DGKζ was confirmed by co-immunoprecipitation and in vitro binding assays, consistent with their co-localization at the periphery of lung cancer cells. The C34 domain of ERK3 was sufficient for binding to DGKζ, while extracellular-regulated kinase 3 bound to the N-terminal and C1 domains of DGKζ. Surprisingly, in contrast to extracellular-regulated kinase 3, DGKζ suppresses lung cancer cell migration, suggesting DGKζ might inhibit ERK3-mediated cell motility. Indeed, co-overexpression of exogenous DGKζ and extracellular-regulated kinase 3 completely blocked the ability of ERK3 to promote cell migration, but DGKζ did not affect the migration of cells with stable ERK3 knockdown. Furthermore, DGKζ had little effect on cell migration induced by overexpression of an ERK3 mutant missing the C34 domain, suggesting DGKζ requires this domain to prevent ERK3-mediated increase in cell migration. In summary, this study has identified DGKζ as a new binding partner and negative regulator of extracellular-regulated kinase 3 in controlling lung cancer cell migration.

Metabolic Profiling of Different Parts of Acer truncatum from the Mongolian Plateau Using UPLC-QTOF-MS with Comparative Bioactivity Assays.

Acer truncatum is an important ornamental, edible, and medicinal plant resource in China. Previous phytochemical research has focused on the leaf (AL) due to its long history as a tea for health. Other parts such as the branch (ABr), bark (ABa), fruit (AF), and root (AR) have drawn little attention regarding their metabolites and bioactivities. The strategy of an in-house chemical library combined with Progenesis QI informatics platform was applied to characterize the metabolites. A total of 98 compounds were characterized or tentatively identified, including 63 compounds reported from this species for the first time. Principal component analysis showed the close clustering of ABr, ABa, and AR, indicating that they share similar chemical components, while AL and AF clustered more distantly. By multiple orthogonal partial least-squares discriminant analyses (OPLS-DA), 52 compounds were identified as potential marker compounds differentiating these different plant parts. The variable influence on projection score from OPLS-DA revealed that catechin, procyanidins B2 or B3, and procyanidins C1 or C2 are the significant metabolites in ABa extracts, which likely contribute to its antioxidant and cytotoxic activities.

The atypical MAPK ERK3 potently suppresses melanoma cell growth and invasiveness.

Mitogen-activated protein kinase 6 (MAPK6) represents an atypical MAPK also known as extracellular signal-regulated kinase 3 (ERK3), which has been shown to play roles in cell motility and metastasis. ERK3 promotes migration and invasion of lung cancer cells and head and neck cancer cells by regulating the expression and/or activity of proteins involved in cancer progression. For instance, ERK3 upregulates matrix metallopeptidases and thereby promotes cancer cell invasiveness, and it phosphorylates tyrosyl-DNA phosphodiesterase 2, thereby enhancing chemoresistance in lung cancer. Here we discovered that ERK3 plays a converse role in melanoma. We observed that BRAF, an oncogenic Ser/Thr kinase, upregulates ERK3 expression levels by increasing both ERK3 messenger RNA levels and protein stability. Interestingly, although BRAF's kinase activity was required for upregulating ERK3 gene transcription, BRAF stabilized ERK3 protein in a kinase-independent fashion. We further demonstrate that ERK3 inhibits the migration, proliferation and colony formation of melanoma cells. In line with this, high level of ERK3 predicted increased survival among patients with melanomas. Taken together, these results indicate that ERK3 acts as a potent suppressor of melanoma cell growth and invasiveness.

Effectiveness of the emergency response course in improving student physical therapists' and licensed physical therapists' decision-making related to acute sports injuries and medical conditions.

PURPOSE: To analyze the effectiveness of the American Red Cross Emergency Response Course (ARC ERC) in improving decision-making skills of physical therapists (PTs) and third semester clinical doctorate student physical therapists (SPTs) when assessing acute sports injuries and medical conditions. METHODS: An existing questionnaire was modified, with permission from the original authors of the instrument. The questionnaire was administered to PTs and SPTs before the start of and immediately after the completion of 5 different ARC ERCs. The overall percentages of "Appropriate" responses for the 17 case scenarios were calculated for each participant for the pre-and post-tests. Participants also rated their perceived level of preparedness for managing various conditions using a 5-point Likert Scale (ranging from Prepared to Unprepared). The overall percentage of "Prepared/Somewhat Prepared" responses for the 16 medical conditions was calculated for each participant for the pre-and post-tests. In addition, mean Likert scale scores were calculated for level of perceived preparedness for each of the 16 medical conditions. Paired t-tests, calculated with SPSS 20.0, were used to analyze the data. RESULTS: 37 of 37 (100.0%) of eligible PTs and 45 of 48 (93.8%) of eligible SPTs completed the pre- and post-test questionnaires. The percentage of "Appropriate" responses for all 17 cases in the aggregate (PTs: 76.8% pre-test, 89.0% post-test; SPTs: 68.5%, 84.3%), as well as the percentage of "Prepared/Somewhat Prepared" responses for all conditions in the aggregate (PTs: 67.5%, 96.5%; SPTs: 37.1%, 90.6%) were significantly different from pre-test to post-test (P = .000). There was also a significant difference (P < .05) in the mean overall preparedness Likert scale scores from pre-test to post-test for each medical condition for the SPT's, and 15 of the 16 medical conditions (muscle strains: P = .119) for the PTs. CONCLUSIONS: The ARC ERC appears to be effective in improving both PTs' and SPTs' decision-making skills related to acute sports injuries and medical conditions, as both "Appropriate" responses and perceived level of preparedness improved. LEVEL OF EVIDENCE: Level 3.