Hyper-phosphorylation of Rb S249 together with CDK5R2/p39 overexpression are associated with impaired cell adhesion and epithelial-to-mesenchymal transition: Implications as a potential lung cancer grading and staging biomarker

Creation of Formalin-Fixed, Paraffin-Embedded 3D Lung Cancer Cellular Spheroids for the Optimization of Immunohistochemistry Staining Procedures

In an era of precision medicine important treatment decisions are dictated by expression of clinically informative tumor protein biomarkers. These biomarkers can be detected by immunohistochemistry (IHC) performed in tumor tissue sections obtained from biopsies or resections. Like all experimental procedures, IHC needs optimization for several of its steps. However, the investigator must avoid optimizing the IHC procedure using valuable human biopsy samples which may be difficult to obtain. Ideally, valuable biopsy samples should only be subjected to IHC once the IHC protocol has been optimized. In this chapter, we describe a procedure for IHC optimization using tri-dimensional (3D) cellular spheroids created from cultured cells. In this approach, cultured cells are pelleted into 3D spheroids, which are then processed just like a tissue sample, namely, fixed, embedded, sectioned, mounted on slides, and stained with IHC just like a human tissue sample. These 3D cellular spheroids have a tissue-like architecture and cellularity resembling a tumor section, and both cellular and antigen structure are preserved. This method is therefore acceptable for IHC optimization before proceeding to the IHC staining of human tumor samples.

Immunoblot Validation of Phospho-Specific Antibodies Using Lung Cancer Cell Lines

The cancer phenotype is usually characterized by deregulated activity of a variety of cellular kinases, with consequent abnormal hyper-phosphorylation of their target proteins. Therefore, antibodies that allow the detection of phosphorylated versions of proteins have become important tools both preclinically in molecular cancer research, and at the clinical level by serving as tools in pathological analyses of tumors. In order to ensure reliable results, validation of the phospho-specificity of these antibodies is extremely important, since this ensures that they are indeed able to discriminate between the phosphorylated and unphosphorylated versions of the protein of interest, specifically recognizing the phosphorylated variant. A recommended validation approach consists in dephosphorylating the target protein and assessing if such dephosphorylation abrogates antigen immunoreactivity when using the phospho-specific antibody. In this chapter, we describe a protocol to validate the specificity of a phospho-specific antibody that recognizes a phosphorylated variant of the Retinoblastoma (Rb) protein in lung cancer cell lines. The protocol consists in the dephosphorylation of the Rb-containing protein lysates by treating them with bovine intestinal phosphatase, followed by assessment of the dephosphorylation by immunoblot.

Protein phosphatase 1 in tumorigenesis: is it worth a closer look?

Cancer cells take advantage of signaling cascades to meet their requirements for sustained growth and survival. Cell signaling is tightly controlled by reversible protein phosphorylation mechanisms, which require the counterbalanced action of protein kinases and protein phosphatases. Imbalances on this system are associated with cancer development and progression. Protein phosphatase 1 (PP1) is one of the most relevant protein phosphatases in eukaryotic cells. Despite the widely recognized involvement of PP1 in key biological processes, both in health and disease, its relevance in cancer has been largely neglected. Here, we provide compelling evidence that support major roles for PP1 in tumorigenesis.

Zoledronic Acid Abrogates Restraint Stress-Induced Macrophage Infiltration, PDGF-AA Expression, and Ovarian Cancer Growth

Simple Summary

Biobehavioral disorders can negatively impact patients with ovarian cancer. Growing evidence suggests that chronic stress can promote tumor progression, the release of inflammatory mediators, and macrophage infiltration into the tumor. However, the role of stress hormones in regulating cancer cell/macrophage crosstalk remains unclear. This study aimed to assess the role of stress hormone-stimulated macrophages in modulating inflammatory networks and ovarian cancer biology. Our data show that stress hormones induced secretion of inflammatory proteins in ovarian cancer cell/macrophage co-cultures. Furthermore, we show that restraint stress leads to cancer growth, macrophage infiltration, and PDGF-AA protein expression in animal models of ovarian cancer. Conversely, zoledronic acid was able to prevent the effects of restraint stress on ovarian cancer growth. Overall, our data suggest a role for stress hormone-stimulated macrophages in ovarian cancer progression and suggest the involvement of PDGF-AA as a key mediator of this process.

Abstract

Multiple studies suggest that chronic stress accelerates the growth of existing tumors by activating the sympathetic nervous system. Data suggest that sustained adrenergic signaling can induce tumor growth, secretion of pro-inflammatory cytokines, and macrophage infiltration. Our goal was to study the role of adrenergic-stimulated macrophages in ovarian cancer biology. Cytokine arrays were used to assess the effect of adrenergic stimulation in pro-tumoral cytokine networks. An orthotopic model of ovarian cancer was used to assess the in vivo effect of daily restraint stress on tumor growth and adrenergic-induced macrophages. Cytokine analyses showed that adrenergic stimulation modulated pro-inflammatory cytokine secretion in a SKOV3ip1 ovarian cancer cell/U937 macrophage co-culture system. Among these, platelet-derived growth factor AA (PDGF-AA), epithelial cell-derived neutrophil-activating peptide (ENA-78), Angiogenin, vascular endothelial growth factor (VEGF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-5 (IL-5), Lipocalin-2, macrophage migration inhibitory factor (MIF), and transferrin receptor (TfR) were upregulated. Enriched biological processes included cytokine-mediated signaling pathways and positive regulation of cell proliferation. In addition, daily restraint stress increased ovarian cancer growth, infiltration of CD68+ macrophages, and expression of PDGF-AA in orthotopic models of ovarian cancer (SKOV3ip1 and HeyT30), while zoledronic acid, a macrophage-depleting agent, abrogated this effect. Furthermore, in ovarian cancer patients, high PDGFA expression correlated with worse outcomes. Here, it is shown that the adrenergic regulation of macrophages and PDGFA might play a role in ovarian cancer progression.

Low mutation burden and differential tumor-infiltrating immune cells correlate with lymph node metastasis in colorectal cancer

BACKGROUND

Tumor immunotherapy has become an important means of cancer treatment. A response depends on the interaction of tumor cells with immune regulators in the tumor microenvironment, which plays an important role in inhibiting or enhancing the immune response. However, lymph node (LN) metastasis leads to major changes in the tumor microenvironment of patients with colorectal cancer, directly affecting prognosis.

METHODS

Using data downloaded from the Cancer Genome Atlas (TCGA) database, we studied the microenvironmental differences between LN-negative and positive populations by bioinformatic methods.

RESULTS

Patients in the LN-positive group had significantly lower immune scores, cytolytic activity scores, and overall survival than the LN-negative group. In addition, a high mutation burden and a new antigen burden could inhibit lymph node metastasis of CRC. In particular, in the LN positive group, the ratio of monocytes to M1 macrophages was significantly downregulated. After the differentially expressed mRNAs between the LN positive and negative groups were determined, a new CRC model was constructed based on multivariate Cox proportional hazard regression analysis to examine the prognosis of patients. The analyses showed that the model was stable and robust.

CONCLUSIONS

We used multiple scores and details of immune cell infiltration as indicators to assess changes in the tumor microenvironment of CRC patients before and after lymph node metastasis, and quantify and model the immune cells in the microenvironment to predict the overall survival of CRC patients.

Identification of prognostic signature of non-small cell lung cancer based on TCGA methylation data

Non–small lung cancer (NSCLC) is a common malignant disease with very poor outcome. Accurate prediction of prognosis can better guide patient risk stratification and treatment decision making, and could optimize the outcome. Utilizing clinical and methylation/expression data in The Cancer Genome Atlas (TCGA), we conducted comprehensive evaluation of early-stage NSCLC to identify a methylation signature for survival prediction. 349 qualified cases of NSCLC with curative surgery were included and further grouped into the training and validation cohorts. We identified 4000 methylation loci with prognostic influence on univariate and multivariate regression analysis in the training cohort. KEGG pathway analysis was conducted to identify the key pathway. Hierarchical clustering and WGCNA co-expression analysis was performed to classify the sample phenotype and molecular subtypes. Hub 5′-C-phosphate-G-3′ (CpG) loci were identified by network analysis and then further applied for the construction of the prognostic signature. The predictive power of the prognostic model was further validated in the validation cohort. Based on clustering analysis, we identified 6 clinical molecular subtypes, which were associated with different clinical characteristics and overall survival; clusters 4 and 6 demonstrated the best and worst outcomes. We identified 17 hub CpG loci, and their weighted combination was used for the establishment of a prognostic model (RiskScore). The RiskScore significantly correlated with post-surgical outcome; patients with a higher RiskScore have worse overall survival in both the training and validation cohorts (P < 0.01). We developed a novel methylation signature that can reliably predict prognosis for patients with NSCLC.

Mechanistic insight of cyclin-dependent kinase 5 in modulating lung cancer growth

Lung harbors the growth of primary and secondary tumors. Even though numerous factors regulate the complex signal transduction and cytoskeletal remodeling toward the progression of lung cancer, cyclin-dependent kinase 5 (Cdk5), a previously known kinase in the central nervous system, has raised much attention in the recent years. Patients with aberrant Cdk5 expression also lead to poor survival. Cdk5 has already been employed in various cellular processes which shape the fate of cancer. In lung cancer, Cdk5 mainly regulates tumor suppressor genes, carcinogenesis, cytoskeletal remodeling, and immune checkpoints. Inhibiting Cdk5 by using drugs, siRNA or CRISP-Cas9 system has rendered crucial therapeutic advantage in the combat against lung cancer. Thus, the relation of Cdk5 to lung cancer needs to be addressed in detail. In this review, we will discuss various cellular events modulated by Cdk5 and we will go further into their underlying mechanism in lung cancer.