Calcium/calmodulin-dependent protein kinase kinase 2 mediates pleiotropic effects of epidermal growth factor in cancer cells

AIMS

Engagement of epidermal growth factor (EGF) with its receptor (EGFR) produces a broad range of cancer phenotypes. The overriding aim of this study was to understand EGFR signaling and its regulation by the Ca²⁺/calmodulin (CaM) dependent protein kinase kinase 2 (CaMKK2) in cancer cells.

RESULTS

In ovarian cancer cells and other cancer cell types, EGF-induced activation of oncogenic Akt is mediated by both the canonical PI3K-PDK1 pathway and by CaMKK2. Akt activation induced by EGF occurs by both calcium-dependent and calcium-independent mechanisms. In contrast to the canonical pathway, CaMKK2 neither binds to, nor is regulated by phosphoinositides but is activated by Ca²⁺/CaM. Akt activation at its primary activation site, T308 occurs by direct phosphorylation by CaMKK2, but activation at its secondary site (S473), is through an indirect mechanism requiring mTORC2. In cells in which another CaMKK2 target, 5'AMP-dependent protein kinase (AMPK) was deleted, Akt activation and calcium-dependency of activation were still observed. CaMKK2 accumulates in the nucleus in response to EGF and regulates transcription of phosphofructokinase platelet (PFKP) a glycolytic regulator. CaMKK2 is required for optimal PFK activity. CaMKK2 regulates transcription of plasminogen activator, urokinase (PLAU) a metastasis regulator. The EGFR inhibitor gefitinib synergizes with CaMKK2 inhibition in the regulation of cell survival and increases the dose-reduction index. CRISPR/Cas9 knockout of CaMKK2 leads to compensatory PTEN downregulation and upregulation of Akt activation.

CONCLUSIONS

CaMKK2-mediation of EGFR action may enable cancer cells to use intracellular calcium elevation as a signal for growth and survival.

The impact of group psychological interventions on distress in infertile women

Infertile women express higher levels of distress than fertile women, with distress peaking between the 2nd and 3rd year. The purpose of this study was to determine whether group psychological interventions could prevent this surge. One hundred eighty-four women who had been trying to conceive between 1 and 2 years were randomized into either a cognitive-behavioral group, a support group, or a control group. All experimental participants attended a 10-session group program. Participants completed psychological questionnaires at intake and again at 6 and 12 months. Substantial attrition occurred, particularly in the control group. The cognitive-behavioral and support participants experienced significant psychological improvement at 6 and 12 months compared with the control participants, with the cognitive-behavioral participants experiencing the greatest positive change.

The impact of group psychological interventions on distress in infertile women

Infertile women express higher levels of distress than fertile women, with distress peaking between the 2nd and 3rd year. The purpose of this study was to determine whether group psychological interventions could prevent this surge. One hundred eighty-four women who had been trying to conceive between 1 and 2 years were randomized into either a cognitive-behavioral group, a support group, or a control group. All experimental participants attended a 10-session group program. Participants completed psychological questionnaires at intake and again at 6 and 12 months. Substantial attrition occurred, particularly in the control group. The cognitive-behavioral and support participants experienced significant psychological improvement at 6 and 12 months compared with the control participants, with the cognitive-behavioral participants experiencing the greatest positive change.

Impact of group psychological interventions on pregnancy rates in infertile women

OBJECTIVE

To determine the efficacy of two different group psychological interventions on viable pregnancy rates in women experiencing infertility of less than 2 years' duration.

DESIGN

Prospective, controlled, single-blind, randomized study.

SETTING

Large tertiary-care teaching hospital.

PATIENT(S)

One hundred eighty-four women who had been trying to get pregnant for 1 to 2 years.

INTERVENTION(S)

Participants were randomized into a 10-session cognitive-behavioral group, a standard support group, or a routine care control group. They were followed for 1 year.

MAIN OUTCOME MEASURE(S)

Viable pregnancy.

RESULT(S)

Sixty-four [corrected] women discontinued participation in the study within the first year. There were a total of 47 in the cognitive-behavioral group, 48 in the support group, and 25 in the control group. There were statistically significant differences between participants in the two intervention groups versus the control group.

CONCLUSION(S)

Group psychological interventions appear to lead to increased pregnancy rates in infertile women.

Biological monitoring of a worker acutely exposed to MBOCA

A 30 year-old male polyurethane worker was exposed to an accidental spill of 4,4'-methylene-bis-2-chloroaniline (MBOCA) at a plant producing MBOCA-cured plastic products. Exposure to MBOCA is significant in that this compound is a known animal carcinogen and a suspected human carcinogen. The employee was sprayed over his upper body and extremities with molten MBOCA while cleaning out a clogged hose from a MBOCA and polymer mixing machine. The subsequent environmental and medical evaluation of this episode included serial urinary MBOCA samples from the worker over a 2 week period to allow the calculation of a biological half-life for this compound. This worker experienced a very high dose of MBOCA as judged by his urinary MBOCA levels (peak value of 1,700 ppb 4 hours after exposure). There were no acute symptoms or other laboratory abnormalities noted. The kinetic evaluation resulted in a biological half-life for MBOCA in urine of approximately 23 hours. Assuming a one-compartment model, approximately 94% of an initial MBOCA dose will be eliminated within four days. This is the first report of kinetic analysis on urinary MBOCA excretion in humans. This information suggests that biological monitoring of the urine MBOCA concentrations in exposed workers may miss peak levels following an acute exposure unless the analyses of the urinary MBOCA are performed in a timely fashion. Recommendations to the company included: 1) installation of a warning system or lock-out device on the mixing machine to prevent the opening of the MBOCA hose prior to the release of pressure; and 2) annual medical surveillance of this individual for bladder cancer with urinalysis and urine cytology.

Efficacy of urinary monitoring for 4,4'-methylenebis (2-chloroaniline)

The aromatic amine 4,4'-methylenebis (2-chloroaniline) (MBOCA), an animal carcinogen, is used commercially as a curing agent for isocyanate-containing polymers. It is structurally similar to other aromatic amines that cause bladder cancer in occupationally exposed workers. Since the late 1970s, MBOCA users have relied on urinary monitoring as the primary method of assessing MBOCA exposure in the workplace. This paper (1) outlines uncertainties about MBOCa's metabolism in humans that complicate interpretation of urinary MBOCA results; (2) describes alternative laboratory techniques for measuring MBOCA in urine; and (3) discusses observations from site visits concerning the practical application of urinary monitoring. Recommendations to improve the efficacy of monitoring programs for urinary MBOCA are outlined.

A cytogenetic study of papaya workers exposed to ethylene dibromide

Ethylene dibromide (EDB) has been shown to be carcinogenic in animal studies and mutagenic in vitro. One cytogenetic study of workers exposed to low levels of EDB for short durations was negative. To test whether exposure to low levels of EDB over long periods caused cytogenetic changes, we have assessed the frequencies of sister-chromatid exchanges (SCE) and chromosomal aberrations (CA) in the peripheral blood lymphocytes of 60 men occupationally exposed to EDB. These men worked in papaya-packing plants where EDB was used to fumigate the fruit after harvest to kill fruit-fly larvae. 42 other men who worked at a nearby sugar mill served as controls. The average duration of exposure of the papaya workers was 5 years. 82 full shift personal breathing-zone air samples indicated that the papaya workers were exposed to a geometric mean of 88 ppb of EDB, as an 8-h time weighted average (TWA). Peaks up to 262 ppb were measured. The proposed OSHA 8-h TWA for EDB is 100 ppb, while NIOSH recommends 45 ppb. No differences in SCE levels were found between exposed and nonexposed workers. No differences were found in the total CA frequency between exposed and nonexposed workers. SCE levels were significantly increased in men who smoked cigarettes (p = 0.0001) and in men who smoked marijuana (p = 0.01). CA levels showed a significant increasing trend with age (p = 0.03).

Emotional responses to infertility. Nursing interventions

Couples and individuals vary in their responses to the infertility experience. The specific emotional stages that couples and individuals pass through as they cope with their infertility are discussed. Appropriate nursing interventions are suggested for each specific stage.

Cytogenetic studies in humans after short-term exposure to ethylene dibromide

Ethylene dibromide (EDB) has been shown to increase sister chromatid exchange in animal cells in vitro, but its cytogenetic effects in humans have not been previously studied. A solution containing EDB is used in the summer months in Colorado to spray felled pine trees to kill pine beetles. We have assessed the frequencies of sister chromatid exchanges and chromosomal aberrations in the peripheral blood lymphocytes of 14 sprayers both before and after exposure. Six nonexposed individuals also were tested. Full-shift personal breathing-zone air samples indicated that the sprayers were exposed to an average of 60 ppb of EDB, as an eight-hour time weighted average. The range of exposure was from 5 to 281 ppb. Workers sprayed EDB for only five to 26 days during the summer, with an average of 14 days. After adjusting for smoking and the use of prescription medicine, there was no statistically significant difference between the frequencies of either sister chromatid exchange or chromosomal aberrations before and after spraying.