Immune system: a double-edged sword in cancer

Objective

The objective of the review is to examine the role of innate and adaptive immune cells in cancer.

Introduction

Immune system functions as a host defensive mechanism protecting against invading pathogens and transformed cells, including cancer. However, a body of research carried out over the last few decades has disclosed the unexpected role of immune system in fostering the tumor growth.

Methods

A computer-based online search was performed in the PubMed, Scopus and Web of Science databases for articles published, concerning natural killer (NK) cells, Macrophages, CD4+ and CD8+ T cells with relevance to cancer. After finding relevant articles within these search limits, a manual search was conducted through the references from these articles.

Results and Conclusions

This review summarizes the role of immune system in Immunosurveillance and Immunoediting. It then focused mainly on role of macrophages, regulatory T cells (Treg), T_H17 cells and on the immunosuppressive mechanisms, which facilitate immune evasion of tumor cells. Our results shows that, immune cells, such as CD8+ cytotoxic T lymphocytes (CTL), CD4+ T helper (T_H)1 cells and NK cells along with their characteristic cytokine interferon (IFN)-γ, function as major antitumor effector cells. Whereas CD4+T_H2 cells, myeloid-derived suppressor cells (MDSCs) and their derived cytokines function as dominant tumor-promoting forces. In contrast to these cells, macrophages, Treg, and T_H17 cells show a dual effect in cancer. Thus, it appears that most components of the immune system are potentially endowed with dual functions i.e., promoting tumor development on the one hand and restraining tumor development on the other and hence immune system can be considered as a double-edged sword in cancer.     

Biodegradation of aromatic compounds: an overview of meta-fission product hydrolases

Meta fission product (MFP) hydrolases catalyze hydrolysis of a low reactive carbon-carbon bond found in meta-fission products, generated during biodegradation of various aromatic compounds. These enzymes belong to the alpha/beta hydrolase super family and show structural conservation despite having poor sequence similarity. MFP-hydrolases are substrate specific and studies have indicated that this substrate specificity plays a key role in the determination of the organism's ability to degrade a particular substrate. In this concise review of MFP-hydrolases we discuss their classification, biochemical properties, the molecular basis of their substrate specificity, their catalytic mechanism, and evolutionary significance.     

Transport-related adverse events in critically-ill children: The role of a dedicated transport team

Objective

To compare the frequency of transport-related adverse events in children during specialized, non-specialized or unassisted transports.

Methods

Patients were grouped based on transport team involved – specialized (Group-1); non-specialized (Group-2); unassisted transport (Group-3). Demographics, events during transport and condition on arrival were recorded.

Results

Group-1 children had a lower incidence of adverse events compared to Group-2 and Group-3 (4.3%, 82.6% and 85.4% respectively; P<0.001). At arrival, children in Group-1 had a lower incidence of respiratory distress and airway compromise (P< 0.001).

Conclusion

Transport of critically ill children by a specialized transport team is associated with fewer transport-related adverse events.