Fluoropyrimidines such as 5-fluorouracil (5-FU) form the foundation of a wide variety of chemotherapy regimens. 5-FU is in fact the third most commonly used chemotherapeutic agent in the treatment of solid malignancies across the world. As with all chemotherapy, balancing the potential benefits of therapy against the risks of drug-related toxicity is crucial when clinicians and patients make shared decisions about treatment. 5-FU is the second most common chemotherapeutic drug associated with cardiotoxicity after anthracyclines, which can manifest as chest pain, acute coronary syndrome/myocardial infarction or death. Nevertheless a widespread appreciation of 5-FU-related cardiotoxicity and its implications is lacking amongst clinicians. In this review, we outline the incidence, possible risk factors, and likely pathophysiological mechanisms that may account for 5-FU-related cardiotoxicity and also highlight potential management strategies for this poorly understood clinical entity.

The ability of breast cancer cells to transiently transition between epithelial and mesenchymal states contributes to their metastatic potential. Therefore, driving tumor cells into a stable mesenchymal state, as opposed to complete tumor cell eradication, presents an opportunity to pharmacologically limit disease progression by promoting an asymptomatic state of dormancy. Here, we compare a reversible model of epithelial-mesenchymal transition (EMT) induced by TGFb to a stable mesenchymal phenotype induced by chronic exposure to the ErbB kinase inhibitor lapatinib. Only cells capable of returning to an epithelial phenotype resulted in skeletal metastasis. Gene expression analyses of the two mesenchymal states indicated similar transition expression profiles. A potently downregulated gene in both datasets was spleen tyrosine kinase (SYK). In contrast to this similar diminution in mRNA, kinome analyses using a peptide array and DNA-conjugated peptide substrates showed a robust increase in SYK activity upon TGFb-induced EMT only. SYK was present in cytoplasmic RNA processing depots known as P-bodies formed during the onset of EMT, and SYK activity was required for autophagy-mediated clearance of P-bodies during mesenchymal-epithelial transition (MET). Genetic knockout of autophagy-related 7 (ATG7) or pharmacologic inhibition of SYK activity with fostamatinib, a clinically approved inhibitor of SYK, prevented P-body clearance and MET, inhibiting metastatic tumor outgrowth. Overall, this study suggests assessment of SYK activity as a biomarker for metastatic disease and the use of fostamatinib as a means to stabilize the latency of disseminated tumor cells.

Translocation to the nucleus of diacylglycerol kinase (DGK)– ζ is dependent on a sequence homologous to the effector domain of Myristoylated Alanine Rich C-Kinase Substrate (MARCKS). These data would suggest that MARCKS could also localize to the nucleus. A single report demonstrated immunofluorescence staining of MARCKS in the nucleus; however, further experimental evidence confirming the specific domain responsible for this localization has not been reported. Here, we report that MARCKS is present in the nucleus in GBM cell lines. We then over-expressed wild-type MARCKS (WT) and MARCKS with the effector domain deleted (ΔED), both tagged with V5-epitope in a GBM cell line with low endogenous MARCKS expression (U87). We found that MARCKS-WT localized to the nucleus, while the MARCKS construct without the effector domain remained in the cytoplasm. We also found that over-expression of MARCKS-WT resulted in a significant increase in total cellular phosphatidyl-inositol (4,5) bisphosphate (PIP2) levels, consistent with prior evidence that MARCKS can regulate PIP2 levels. We also found increased staining for PIP2 in the nucleus with MARCKS-WT over-expression compared to MARCKS ΔED by immunofluorescence. Interestingly, we observed MARCKS and PIP2 co-localization in the nucleus. Lastly, we found changes in gene expression when MARCKS was not present in the nucleus (MARCKS ΔED). These data indicate that the MARCKS effector domain can function as a nuclear localization signal and that this sequence is critical for the ability of MARCKS to regulate PIP2 levels, nuclear localization, and gene expression. These data suggests a novel role for MARCKS in regulating nuclear functions such as gene expression.

The aim of this clinical trial was to compare the clinical performance of three different adhesive systems over 18 months in noncarious cervical lesions (NCCLs). Thirty patients, with at least three noncarious cervical lesions, were enrolled in the study. One operator randomly restored a total of 90 lesions with resin composite (Herculite XRV). The restorations were bonded with either Optibond FL (OF), three-step total-etch; Optibond Solo Plus (OS), two-step total-etch; or Optibond All-In-One (OA), one step self-etch. The restorations were clinically evaluated at baseline and after six, 12, and 18 months using the eight United States Public Health Services criteria. Data were analyzed using Friedman and Wilcoxon signed ranks tests (p<0.05). After 18 months, the retention rate was (OF) 96.5%, (OS) 93.1%, and (OA) 89.7%. Differences among the three adhesive systems for evaluated criteria were not observed in comparison of the mean Alfa score percentages. There was a significant increase in marginal discoloration for (OA) adhesive after 18 months compared with baseline (p=0.011). Other restoration criteria had no statistically significant differences among the three adhesives (p>0.05). With the exception of marginal discoloration, the clinical effectiveness of three types of adhesive systems in NCCLs was acceptable after 18 months. However, using the one-step self-etch adhesive may lead to some marginal discolorations.

Anti-spike monoclonal antibody treatment of 180 B-cell-depleted patients with mild-to-moderate COVID-19 resulted in good outcomes overall, with only 12.2% progressing to severe disease, 9.4% requiring hospitalization, 0.6% requiring mechanical ventilation, no deaths within 30 days, and 1.8% developing persistent COVID-19. Anti-spike monoclonal antibodies appear effective in this immunocompromised population.