Expression of insulin‐like growth factor‐1 receptor in metastatic uveal melanoma and implications for potential autocrine and paracrine tumor cell growth

We investigated the importance of the insulin‐like growth factor‐1 receptor (IGF‐1R) in hepatic metastases of uveal melanoma. The expression pattern of IGF‐1R in archival tissue samples of hepatic metastasis from 24 patients was analyzed by immunohistochemistry. All the samples of hepatic metastases stained positive for IGF‐1R. To investigate the biological role of IGF‐1R on the growth of metastatic uveal melanoma, a long‐term cell line obtained from a hepatic metastasis (TJU‐UM001) was evaluated. TJU‐UM001 expressed cell surface IGF‐1R (>90%) and proliferated in response to exogenous and endogenous insulin‐like growth factor‐1 (IGF‐1). Correlatively, anti‐IGF‐1R antibody completely blocked IGF‐1‐induced growth of TJU‐UM001 cells. IGF‐1 preferentially induced phosphorylation of Akt (S473) in quiescent TJU‐UM001 cells, and this was blocked by anti‐IGF‐1R antibody. This study suggests that autocrine and paracrine mechanisms underlie IGF‐1‐induced growth of metastatic uveal melanoma and underscore the potential benefit of IGF‐1 or IGF‐1R antagonism in treatment for metastatic uveal melanoma.     

Pneumocytes are distinguished by highly elevated expression of the ER stress biomarker GRP78, a co-receptor for SARS-CoV-2, in COVID-19 autopsies

Vaccinations are widely credited with reducing death rates from COVID-19, but the underlying host-viral mechanisms/interactions for morbidity and mortality of SARS-CoV-2 infection remain poorly understood. Acute respiratory distress syndrome (ARDS) describes the severe lung injury, which is pathologically associated with alveolar damage, inflammation, non-cardiogenic edema, and hyaline membrane formation. Because proteostatic pathways play central roles in cellular protection, immune modulation, protein degradation, and tissue repair, we examined the pathological features for the unfolded protein response (UPR) using the surrogate biomarker glucose-regulated protein 78 (GRP78) and co-receptor for SARS-CoV-2. At autopsy, immunostaining of COVID-19 lungs showed highly elevated expression of GRP78 in both pneumocytes and macrophages compared with that of non-COVID control lungs. GRP78 expression was detected in both SARS-CoV-2-infected and un-infected pneumocytes as determined by multiplexed immunostaining for nucleocapsid protein. In macrophages, immunohistochemical staining for GRP78 from deceased COVID-19 patients was increased but overlapped with GRP78 expression taken from surgical resections of non-COVID-19 controls. In contrast, the robust in situ GRP78 immunostaining of pneumocytes from COVID-19 autopsies exhibited no overlap and was independent of age, race/ethnicity, and gender compared with that from non-COVID-19 controls. Our findings bring new insights for stress-response pathways involving the proteostatic network implicated for host resilience and suggest that targeting of GRP78 expression with existing therapeutics might afford an alternative therapeutic strategy to modulate host-viral interactions during SARS-CoV-2 infections.     

Ultrahigh density microarrays of solid samples

We present a sectioning and bonding technology to make ultrahigh density microarrays of solid samples, cutting edge matrix assembly (CEMA). Maximized array density is achieved by a scaffold-free, self-supporting construction with rectangular array features that are incrementally scalable. This platform technology facilitates arrays of >10,000 tissue features on a standard glass slide, inclusion of unique sample identifiers for improved manual or automated tracking, and oriented arraying of stratified or polarized samples.     

Atlantic salmon (Salmo salar) protein hydrolysate in diets for weaning piglets ─ effect on growth performance,intestinal morphometry and microbiota composition

Salmon protein hydrolysates (SPH) from two different rest raw materials were evaluated in diets for weaning piglets. Four experimental diets were included in the study: a diet based on plant protein with soy protein as the main protein source (Diet PP), a diet based on fishmeal in exchange for soy protein (Diet FM) and two diets in which different SPH replaced fishmeal in the FM diet. The experimental diets were fed to piglets from the day of weaning until 32 d postweaning. In addition to the record of performance data, an intestinal sampling for mucosal morphometry and microbiota 16S rRNA gene sequencing were performed at day 11 on a subset of the animals. The duodenal villi absorption area was significantly larger in piglets receiving Diets SPH compared with Diet PP (p < 0.02). A significant positive correlation between duodenal villi height and average daily gain during the first 11 d postweaning was detected. Only small differences in intestinal microbiota community and no differences in growth performance were detected between the experimental diets. To conclude, SPH seem to be an interesting novel protein source in weanling piglets.     

RB-pathway disruption in breast cancer: Differential association with disease subtypes,disease-specific prognosis and therapeutic response

In breast cancer, inactivation of the RB tumor suppressor gene is believed to occur via multiple mechanisms to facilitate tumorigenesis. However, the prognostic and predictive value of RB status in disease-specific clinical outcomes has remained uncertain. We investigated RB pathway deregulation in the context of both ER-positive and ER-negative disease using combined microarray datasets encompassing over 900 breast cancer patient samples. Disease-specific characteristics of RB pathway deregulation were investigated in this dataset by evaluating correlation among pathway genes as well as differential expression across patient tumor populations defined by ER status. Survival analysis among these breast cancer samples demonstrates that the RB-loss signature is associated with poor disease outcome within several independent cohorts. Within the ER-negative subpopulation, the RB-loss signature is associated with improved response to chemotherapy and longer relapse-free survival. Additionally, while individual genes in the RB target signature closely reproduce its prognostic value, they also serve to predict and monitor response to therapeutic compounds, such as the cytostatic agent PD-0332991. These results indicate that the RB-loss signature expression is associated with poor outcome in breast cancer, but predicts improved response to chemotherapy based on data in ER-negative populations. While the RB-loss signature, as a whole, demonstrates prognostic and predictive utility, a small subset of markers could be sufficient to stratify patients based on RB function and inform the selection of appropriate therapeutic regimens.Key words: RB, breast cancer, microarray, proliferation, cytostatics     

Prolactin inhibits activity of pyruvate kinase M2 to stimulate cell proliferation

Mitogenic and prosurvival effects underlie the tumorigenic roles of prolactin (PRL) in the pathogenesis of breast cancer. PRL signaling is mediated through its receptor (PRLr). A proteomics screen identified the pyruvate kinase M2 (PKM2), a glycolytic enzyme known to play an important role in tumorigenesis, as a protein that constitutively interacts with PRLr. Treatment of cells with PRL inhibited pyruvate kinase activity and increased the lactate content in human cells in a manner that was dependent on the abundance of PRLr, activation of Janus kinase 2, and tyrosine phosphorylation of the intracellular domain of PRLr. Knockdown of PKM2 attenuated PRL-stimulated cell proliferation. The extent of this proliferation was rescued by the knock-in of the wild-type PKM2 but not of its mutant insensitive to PRL-mediated inhibition. We discuss a hypothesis that the inhibition of PKM2 by PRL contributes to the PRL-stimulated cell proliferation.     

A validated method for rapid analysis of ethane in breath and its application in kinetic studies in human volunteers

Oxidative stress may initiate lipid peroxidation that generates ethane. Ethane, at low concentrations, is eliminated by pulmonary exhalation. Previous methods have not allowed frequent sampling, thus ethane kinetics has not been studied in man. A validated method over the range 3.8-100,000 ppb with a limit of quantitation of 3.8 ppb (CV 9.3%) based on cryofocusing technique of a 60 ml breath sample allowed frequent sampling. Due to a rapid analytical procedure batches of more than 100 samples may be analyzed. In human volunteers (24-55 years) uptake was studied for up to 23 min (n=9), elimination was studied for 210 min (n=9). Ethane was inhaled (concentrations varied from 16 to 29 ppm (parts per million)) through a non-rebreathing system; sampling was performed with short intervals from the expiratory limb. Samples were also drawn from the inhalatory limb. Ninety-five percent of steady state (inspired) concentration was reached within 1.75 min. Five percent of the initially inhaled concentrations was found in exhaled air 1.5 min after termination of inhalation. A terminal mean half life of 31 min for ethane was also observed. The data indicate that frequent sampling will be necessary to capture relevant changes in breath ethane.