Unravelling transcriptomic complexity in breast cancer through modulation of DARPP-32 expression and signalling pathways

DARPP-32 is a key regulator of protein-phosphatase-1 (PP-1) and protein kinase A (PKA), with its function dependent upon its phosphorylation state. We previously identified DKK1 and GRB7 as genes with linked expression using Artificial Neural Network (ANN) analysis; here, we determine protein expression in a large cohort of early-stage breast cancer patients. Low levels of DARPP-32 Threonine-34 phosphorylation and DKK1 expression were significantly associated with poor patient prognosis, while low levels of GRB7 expression were linked to better survival outcomes. To gain insight into mechanisms underlying these associations, we analysed the transcriptome of T47D breast cancer cells following DARPP-32 knockdown. We identified 202 differentially expressed transcripts and observed that some overlapped with genes implicated in the ANN analysis, including PTK7, TRAF5, and KLK6, amongst others. Furthermore, we found that treatment of DARPP-32 knockdown cells with 17β-estradiol or PKA inhibitor fragment (6-22) amide led to the differential expression of 193 and 181 transcripts respectively. These results underscore the importance of DARPP-32, a central molecular switch, and its downstream targets, DKK1 and GRB7 in breast cancer. The discovery of common genes identified by a combined patient/cell line transcriptomic approach provides insights into the molecular mechanisms underlying differential breast cancer prognosis and highlights potential targets for therapeutic intervention.

African American Cancer Survivors' Perspectives on Cancer Clinical Trial Participation in a Safety-Net Hospital: Considering the Role of the Social Determinants of Health

Although there has been an increase focus on recruitment of minority populations at safety-net hospitals into cancer clinical trials, there is still a paucity of research exploring minority participation in cancer clinical trials at safety-net settings. The study utilized a multi-level, qualitative approach to assess the clinical and non-clinical facilitators and barriers to African American participation in cancer clinical trials at a safety-net hospital. From June 2018 to July 2019, cancer survivors (n = 25) were recruited from a cancer center at a safety-net hospital in the southeastern USA and participated in a 60-min focus group. Data was coded and analyzed to identify the most prominent themes. Most participants were female (78%), with a mean age of 56 years. The majority were diagnosed with breast cancer (68%) and disabled or unemployed (55%). Major themes identified were (1) lack of understanding of cancer clinical trials, (2) perceptions and fears of cancer clinical trials, and (3) preferred role and characteristics of patient navigator. The barriers and facilitators to enrollment in cancer clinical trials were more pronounced in the safety-net setting, given the overdue burden of social determinants of health. Study findings yield important insights and essential practices for recruiting and engaging underrepresented Black cancer patients into cancer clinical trials, specifically for safety-net settings. Including patient navigators may help traverse potential barriers to cancer clinical trial participation and will allow for the attention to social determinants of health, and ultimately increase the number of African Americans participating in cancer clinical trials.

Waist Circumference Adds to the Variance in Plasma C-Reactive Protein Levels in Elderly Patients with Metabolic Syndrome

BACKGROUND

C-reactive protein (CRP), a nonspecific marker of the inflammatory status, is associated with cardiovascular disease risk factors and may be an important feature of the metabolic syndrome (MSX) in middle-aged subjects.

OBJECTIVES

We assessed the relationship of CRP levels to specific components of MSX and other potential determinants in apparently healthy elderly subjects living in the South of France.

METHODS

In the framework of the population-based POLA (Pathologies Oculaires Liées à l'Age) Study, performed in 2,404 subjects aged 60 years or more, we measured the plasma CRP levels. All subjects with known systemic inflammatory diseases, such as chronic bronchitis, cardiovascular disease, and diabetes, and those who were on systemic steroid therapy as well as subjects with CRP levels >10 mg/l were excluded from the study, leaving 1,709 subjects for the statistical analyses. MSX was defined according to NCEP (National Cholesterol Education Program) criteria. Other potential determinants were assessed through interviewer-based questionnaire.

RESULTS

We grouped the subjects into three categories based on the 75th and 25th percentiles, corresponding to 3.05 and 0.82, respectively. We compared subjects in the highest quartile, i.e., with CRP >/=3.05 mg/l, with those in the two intermediate quartiles, i.e., with 0.82 < CRP < 3.05, and those in the lowest quartile, i.e., with CRP <0.82 mg/l according to gender. MSX, which had a prevalence of 31%, was significantly associated with elevated CRP levels. Among MSX components, the strongest positive association with the highest quartile of CRP was with waist circumference in males as well as in females (age-adjusted odds ratio OR 3.06 and 95% confidence interval CI 1.82-5.14; OR 7.04 and 95% CI 4.79-10.34, respectively). Each component of the MSX, such as abnormal fasting plasma glucose (OR 2.90, 95% CI 1.69-4.99), triglycerides (OR 1.96, 95% CI 1.30-2.96), high-density lipoprotein cholesterol (OR 2.31, 95% CI 1.61-3.30), and blood pressure (OR 1.66, 95% CI 1.12-2.45), was significantly associated with high CRP values in elderly women only. In men, only current smoking was significantly associated with high CRP levels (OR 1.52, 95% CI 1.04-2.2). In multivariate analysis, the waist circumference remained significantly associated with high CRP levels, with a graded effect of CRP quartile whatever the gender. In men, current and former smoking remained significantly associated with the CRP levels. In women, the association observed in univariate analysis with fasting glucose or hypertension did not reach statistical significance in the multivariate analysis, while only a weak association could be observed with lipid parameters such as triglycerides and high-density lipoprotein cholesterol.

CONCLUSIONS

Abdominal adiposity adds to the variance in plasma CRP levels in elderly patients with MSX. This suggests that weight loss or other interventions targeted at adipocyte-related inflammation may represent an important means to prevent subclinical inflammation in the elderly, bearing a high risk of cardiovascular disease.

[Diagnostic value of the clinical probability score of deep venous thrombosis in the elderly]

SUBJECT

There is a lack of scientific data concerning the incidence, clinical signs, risk factors and diagnostic management of deep vein thrombosis (DVT) in the elderly.

METHODS

We carried out a prospective case-control study in a geriatric setting. We included one in-patient without clinical signs of deep vein thrombosis for each hospitalised patient with clinically suspected DVT. Clinical signs, risk factors of DVT and a compression ultrasonography of the proximal and distal leg veins were performed in all patients at admission. Also, the clinical probability was assessed by means of the clinical score model described by Wells.

RESULTS

There were 102 patients aged over 85 included during the 5 months period of the study. Fifty-one patients have had a clinical suspicion of DVT and 51 patients were clinically asymptomatic. There were 43% symptomatic DVT and 12% asymptomatic DVT. Clinical signs and symptoms of DVT were neither sensitive nor specific. Risk factors associated most frequently with DVT were: immobilisation (prevalence 64%), paralysis of the legs (22%), varicose veins (25%), deshydratation (28,5%), infections (18%). A significant relationship between a risk factor and DVT was found only for immobilisation (P<0,05) and deshydratation (P<0,02). The prevalence of DVT increased with the clinical probability score: 11.4% for the low score, 27.6% for the moderate score and 55% for the high score.

CONCLUSION

Incidence of DVT is high among hospitalised elderly patients, especially for the asymptomatic ones. Clinical signs alone do not reliably predict DVT. Clinical probability score could be useful to improve diagnostic management of DVT in this population.