The human breast cancer-associated protein, the prolactin-inducible protein (PIP), regulates intracellular signaling events and cytokine production by macrophages

Relative Quantification of Proteins in Formalin-Fixed Paraffin-Embedded Breast Cancer Tissue Using Multiplexed Mass Spectrometry Assays

The identification of clinically relevant biomarkers represents an important challenge in oncology. This problem can be addressed with biomarker discovery and verification studies performed directly in tumor samples using formalin-fixed paraffin-embedded (FFPE) tissues. However, reliably measuring proteins in FFPE samples remains challenging. Here, we demonstrate the use of liquid chromatography coupled to multiple reaction monitoring mass spectrometry (LC-MRM/MS) as an effective technique for such applications. An LC-MRM/MS method was developed to simultaneously quantify hundreds of peptides extracted from FFPE samples and was applied to the targeted measurement of 200 proteins in 48 triple-negative, 19 HER2-overexpressing, and 20 luminal A breast tumors. Quantitative information was obtained for 185 proteins, including known markers of breast cancer such as HER2, hormone receptors, Ki-67, or inflammation-related proteins. LC-MRM/MS results for these proteins matched immunohistochemistry or chromogenic in situ hybridization data. In addition, comparison of our results with data from the literature showed that several proteins representing potential biomarkers were identified as differentially expressed in triple-negative breast cancer samples. These results indicate that LC-MRM/MS assays can reliably measure large sets of proteins using the analysis of surrogate peptides extracted from FFPE samples. This approach allows to simultaneously quantify the expression of target proteins from various pathways in tumor samples. LC-MRM/MS is thus a powerful tool for the relative quantification of proteins in FFPE tissues and for biomarker discovery.

The crucial role of prolactin-lactogenic hormone in Covid-19

Prolactin (PRL) is a peptide hormone secreted from anterior pituitary involved in milk production in the females and regulation of sex drive in both sexes. PRL has pro-inflammatory and anti-inflammatory functions. High PRL serum level or hyperprolactinemia is associated with different viral infections. In coronavirus disease 2019 (Covid-19), which caused by positive-sense single-strand RNA virus known as severe acute respiratory distress syndrome coronavirus type 2 (SARS-CoV-2), PRL serum level is increased. PRL in Covid-19 may exacerbate the underlying inflammatory status by induction release of pro-inflammatory cytokines. However, PRL through its anti-inflammatory effects may reduce the hyperinflammatory status in Covid-19. The underlying mechanism of increasing PRL in Covid-19 is poorly understood. Therefore, in this review we try to find the potential anti-inflammatory or pro-inflammatory role of PRL in Covid-19. As well, this review was aimed to discuss the underlying causes and mechanisms for Covid-19-induced hyperprolactinemia.

The Prolactin Inducible Protein Modulates Antitumor Immune Responses and Metastasis in a Mouse Model of Triple Negative Breast Cancer

The prolactin inducible protein (PIP) is expressed to varying degrees in more than 90% of breast cancers (BCs). Although high levels of PIP expression in BC has been shown to correlate with better prognosis and patient response to chemotherapy, some studies suggest that PIP may also play a role in metastasis. Here, we investigated the role of PIP in BC using the well-established 4T1 and E0771 mouse BC cell lines. Stable expression of PIP in both cell lines did not significantly alter their proliferation, migration, and response to anticancer drugs in vitro compared to empty vector control. To assess the effect of PIP expression on breast tumorigenesis in vivo, the 4T1 syngeneic transplantable mouse model was utilized. In immunocompetent syngeneic BALB/c mice, PIP-expressing 4T1 primary tumors displayed delayed tumor onset and reduced tumor growth, and this was associated with higher percentages of natural killer cells and reduced percentages of type 2 T-helper cells in the tumor environment. The delayed tumor onset and growth were abrogated in immunodeficient mice, suggesting that PIP-mediated modulation of primary tumor growth involves an intact immune system. Paradoxically, we also observed that PIP expression was associated with a higher number of 4T1 colonies in the lungs in both the immunocompetent and immunodeficient mice. Gene expression analysis of PIP-expressing 4T1 cells (4T1-PIP) revealed that genes associated with tumor metastasis such as CCL7, MMP3 and MMP13, were significantly upregulated in 4T1-PIP cells when compared to the empty vector control (4T1-EV) cells. Collectively, these studies strongly suggest that PIP may possess a double-edge sword effect in BC, enhancing both antitumor immunity as well as metastasis.

Peripheral immune tolerance by prolactin-induced protein originated from human invariant natural killer T cells

invariant natural killer T (iNKT) cells have been reported to regulate a diverse set of immunological responses. iNKT cell dysfunction in cytokine secretion is linked to the development of autoimmunity, an immune response against its own tissue. Interestingly, CD4⁺ iNKT cells preferentially secrete regulatory cytokines. Here we investigated what kind of secreting factors of it are involved in dendritic cell (DC) maturation to regulate immune responses. We found one of them, prolactin induced protein (PIP), from the supernatants of cultured CD4⁺ iNKT cells. It was validated using RT-quantitative real-time polymerase chain reaction (RT-qPCR) and western blot analysis. Subsequent analysis upon PIP treatment was performed using fluorescence-activated cell sorting (FACS) analysis. We identified PIP as one of strong candidates for inducing DC maturation, to similar level to lipopolysaccharide, an already known candidate molecule. Recombinant PIP recapitulated natural function, and induction of DC differentiation by both recombinant and purified PIP was blocked by anti-Toll-like receptor (TLR)2 antibody (Ab), but not by anti-TLR4/5 or anti-receptor Ab for advanced glycation end product Ab. Interestingly, PIP induced the differentiation of naïve T cells into CD4⁺ CD25⁺ Foxp3⁺ regulatory T cells and reduced the number of helper T (Th)1 and Th17 cells produced by Pam3CysSerLys4. Take in together, these results suggest that PIP is an important factor that mediates immunoregulation by iNKT cells through TLR2-mediated signaling.

Differentially expressed serum proteins in children with or without asthma as determined using isobaric tags for relative and absolute quantitation proteomics

Background

Although asthma is one of the most common chronic, noncommunicable diseases worldwide, the pathogenesis of childhood asthma is not yet clear. Genetic factors and environmental factors may lead to airway immune-inflammation responses and an imbalance of airway nerve regulation. The aim of the present study was to determine which serum proteins are differentially expressed between children with or without asthma and to ascertain the potential roles that these differentially expressed proteins (DEPs) may play in the pathogenesis of childhood asthma.

Methods

Serum samples derived from four children with asthma and four children without asthma were collected. The DEPs were identified by using isobaric tags for relative and absolute quantitation (iTRAQ) combined with liquid chromatography tandem mass spectrometry (LC-MS/MS) analyses. Using biological information technology, including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Cluster of Orthologous Groups of Proteins (COG) databases and analyses, we determined the biological processes associated with these DEPs. Key protein glucose-6-phosphate dehydrogenase (G6PD) was verified by enzyme linked immunosorbent assay (ELISA).

Results

We found 46 DEPs in serum samples of children with asthma vs. children without asthma. Among these DEPs, 12 proteins were significantly (>1.5 fold change) upregulated and 34 proteins were downregulated. The results of GO analyses showed that the DEPs were mainly involved in binding, the immune system, or responding to stimuli or were part of a cellular anatomical entity. In the KEGG signaling pathway analysis, most of the downregulated DEPs were associated with cardiomyopathy, phagosomes, viral infections, and regulation of the actin cytoskeleton. The results of a COG analysis showed that the DEPs were primarily involved in signal transduction mechanisms and posttranslational modifications. These DEPs were associated with and may play important roles in the immune response, the inflammatory response, extracellular matrix degradation, and the nervous system. The downregulated of G6PD in the asthma group was confirmed using ELISA experiment.

Conclusion

After bioinformatics analyses, we found numerous DEPs that may play important roles in the pathogenesis of childhood asthma. Those proteins may be novel biomarkers of childhood asthma and may provide new clues for the early clinical diagnosis and treatment of childhood asthma.

Poor stimulation of bovine dendritic cells by Mycobacterium bovis culture supernatant and surface extract is associated with decreased activation of ERK and NF-B and higher expression of SOCS1 and 3

The cell envelope of pathogenic mycobacteria interfaces with the host. As such, the interaction of bacterial products localized at or released from the cell surface with the host’s immune system can determine the fate of the bacterium in its host. In this study, the effects of three different types of Mycobacterium bovis cell envelope fractions—purified protein derivative, total cell wall lipids and culture supernatant and surface extract—on bovine dendritic cells were assessed. We found that the culture supernatant and surface extract fraction induced little to no production of the pro-inflammatory cytokines TNF-α and IL-12 in bovine dendritic cells. Moreover, this muted response was associated with poor activation of ERK and NF-κB, both of which are critical for the pro-inflammatory response. Furthermore, culture supernatant and surface extract treatment increased the expression of suppressor of cytokine signaling 1 and 3, both of which are negative regulators of pro-inflammatory signaling, in bovine dendritic cells. These observations taken together suggest the M. bovis culture supernatant and surface extract fraction contain immunomodulatory molecules that may aid in M. bovis pathogenesis.

Regulation of Immunity in Breast Cancer

Breast cancer affects millions of women worldwide, leading to many deaths and significant economic burden. Although there are numerous treatment options available, the huge potentials of immunotherapy in the management of localized and metastatic breast cancer is currently being explored. However, there are significant gaps in understanding the complex interactions between the immune system and breast cancer. The immune system can be pro-tumorigenic and anti-tumorigenic depending on the cells involved and the conditions of the tumor microenvironment. In this review, we discuss current knowledge of breast cancer, including treatment options. We also give a brief overview of the immune system and comprehensively highlight the roles of different cells of the immune system in breast tumorigenesis, including recent research discoveries. Lastly, we discuss some immunotherapeutic strategies for the management of breast cancer.

Fast quantitative urinary proteomic profiling workflow for biomarker discovery in kidney cancer

Background

Urine has evolved as a promising body fluids in clinical proteomics because it can be easily and noninvasively obtained and can reflect physiological and pathological status of the human body. Many efforts have been made to characterize more urinary proteins in recent years, but few have focused on the analysis throughput and detection reproducibility. Increasing the urine proteomic profiling throughput and reproducibility is urgently needed for discovering potential biomarker in large cohorts.

Methods

In this study, we developed a fast and robust workflow for streamlined urinary proteome analysis. The workflow integrate highly efficient sample preparation technique and urinary specific data-independent acquisition (DIA) approach. The performance of the workflow was systematically evaluated and the workflow was subsequently applied in a proof-of-concept urine proteome study of 21 kidney cancer (KC) patients and 22 healthy controls.

Results

With this workflow, the entire sample preparation process takes less than 3 h and allows multiplexing on standard centrifuges. Without pre-fractionation, our newly developed DIA method allows quantitative analysis of ~ 1000 proteins within 80 min of MS time (~ 15 samples/day). The quantitation accuracy of the whole workflow was excellent with median CV of 9.1%. The preliminary study on KC identified 125 significantly changed proteins.

Conclusions

The result suggested the feasibility of applying the high throughput workflow in extensive urinary proteome profiling and clinical relevant biomarker discovery.

Electronic supplementary material

The online version of this article (10.1186/s12014-018-9220-2) contains supplementary material, which is available to authorized users.