Despite the skepticism that once prevailed among immunologists, it is now widely accepted that the normal immune system harbors a T-cell population, called regulatory T cells (Treg cells), specialized for immune suppression. It was first shown that depletion of a T-cell subpopulation from normal rodents produced autoimmune disease. Search for a molecular marker specific for such autoimmune-preventive Treg cells has revealed that the majority, if not all, of them constitutively express the CD25 molecule as depletion of CD25+CD4+ T cells spontaneously evokes autoimmune disease in otherwise normal rodents. The expression of CD25 by Treg cells has made it possible to delineate their developmental pathways, in particular their thymic development, and establish simple in vitro assay for assessing their suppressive activity. The marker and the in vitro assay have helped to identify human Treg cells with similar functional and phenotypic characteristics. Recent efforts have shown that natural Treg cells specifically express the transcription factor Foxp3 and that mutations of the Foxp3 gene produce a variety of immunological diseases in humans and rodents. Specific expression of Foxp3 in natural Treg cells has enabled their functional and developmental characterization by genetic approach. These studies altogether have provided firm evidence for Foxp3+CD25+CD4+ Treg cells as an indispensable cellular constituent of the normal immune system for establishing and maintaining immunologic self-tolerance and immune homeostasis. Treg cells are now within the scope of clinical use to treat immunological diseases and control physiological and pathological immune responses.

Regulatory T Cells

Interleukin-22 (IL-22) is a recently described IL-10 family cytokine that is produced by T helper (Th) 17 cells, γδ T cells, NKT cells, and newly described innate lymphoid cells (ILCs). Knowledge of IL-22 biology has evolved rapidly since its discovery in 2000, and a role for IL-22 has been identified in numerous tissues, including the intestines, lung, liver, kidney, thymus, pancreas, and skin. IL-22 primarily targets nonhematopoietic epithelial and stromal cells, where it can promote proliferation and play a role in tissue regeneration. In addition, IL-22 regulates host defense at barrier surfaces. However, IL-22 has also been linked to several conditions involving inflammatory tissue pathology. In this review, we assess the current understanding of this cytokine, including its physiologic and pathologic effects on epithelial cell function.

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Interleukin-22: Immunobiology and Pathology

The use of biomarkers in diagnosis, therapy and prognosis has gained increasing interest over the last decades. In particular, the analysis of biomarkers in cancer patients within the pre- and post-therapeutic period is required to identify several types of cells, which carry a risk for a disease progression and subsequent post-therapeutic relapse. Cancer stem cells (CSCs) are a subpopulation of tumor cells that can drive tumor initiation and can cause relapses. At the time point of tumor initiation, CSCs originate from either differentiated cells or adult tissue resident stem cells. Due to their importance, several biomarkers that characterize CSCs have been identified and correlated to diagnosis, therapy and prognosis. However, CSCs have been shown to display a high plasticity, which changes their phenotypic and functional appearance. Such changes are induced by chemo- and radiotherapeutics as well as senescent tumor cells, which cause alterations in the tumor microenvironment. Induction of senescence causes tumor shrinkage by modulating an anti-tumorigenic environment in which tumor cells undergo growth arrest and immune cells are attracted. Besides these positive effects after therapy, senescence can also have negative effects displayed post-therapeutically. These unfavorable effects can directly promote cancer stemness by increasing CSC plasticity phenotypes, by activating stemness pathways in non-CSCs, as well as by promoting senescence escape and subsequent activation of stemness pathways. At the end, all these effects can lead to tumor relapse and metastasis. This review provides an overview of the most frequently used CSC markers and their implementation as biomarkers by focussing on deadliest solid (lung, stomach, liver, breast and colorectal cancers) and hematological (acute myeloid leukemia, chronic myeloid leukemia) cancers. Furthermore, it gives examples on how the CSC markers might be influenced by therapeutics, such as chemo- and radiotherapy, and the tumor microenvironment. It points out, that it is crucial to identify and monitor residual CSCs, senescent tumor cells, and the pro-tumorigenic senescence-associated secretory phenotype in a therapy follow-up using specific biomarkers. As a future perspective, a targeted immune-mediated strategy using chimeric antigen receptor based approaches for the removal of remaining chemotherapy-resistant cells as well as CSCs in a personalized therapeutic approach are discussed.

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Cancer Stem Cells-Origins and Biomarkers: Perspectives for Targeted Personalized Therapies.

Tumor metastasis is a multi-step process by which tumor cells disseminate from their primary site and form secondary tumors at a distant site. And metastasis is the major cause of death in the vast majority of cancer patients. However, the mechanisms underlying each step remain obscure. In the past decade, a developmental program epithelial-to-mesenchymal transition (EMT) has been increasingly recognized to play pivotal and intricate roles in promoting carcinoma invasion and metastasis. The EMT process is very complex and controlled by various families of transcriptional regulators through different signaling pathways. In this system review, we focus on the molecular network of the EMT program and its malignant phenotypes associated with metastasis in colorectal cancer (CRC), including cancer stem cells, tumor budding, circulating tumor cells and drug resistance. A better understanding of the molecular regulation of the dynamic EMT program during tumor metastasis will help to provide much-needed therapeutic interventions to target this program when treating metastatic CRC.

Epithelial–mesenchymal transition in colorectal cancer metastasis: A system review

Phase I trial: the use of autologous cultured adipose-derived stroma/stem cells to treat patients with non-revascularizable critical limb ischemia

Octamer-binding transcription factor 4 (OCT4) has been implicated in cancer metastasis. In this study, we investigated whether OCT4 promotes colorectal cancer (CRC) metastasis through the epithelial-mesenchymal transition (EMT) process. We designed our experiment as a loss-of-function study. Western blot analysis was used to measure the extent and stability of OCT4 knockdown. We evaluated the metastatic phenotype of OCT4-silenced SW620 cells using standard migration and invasion assays in vitro and the commonly used mouse model for experimental metastases in vivo. We found that OCT4 knockdown inhibited colorectal cancer cell motility and invasion (in vitro) and decreased hepatic colonization (in vivo). It also induced changes in EMT characteristic cell morphology and marker gene expression. In addition, its knockdown decreased WNT pathway activity. Finally, in human primary colorectal cancers, the frequency of upregulated OCT4 expression in cases with liver metastasis was statistically higher than that in cases without liver metastasis. These results indicate that OCT4 may contribute to CRC cell metastasis through EMT and serves as a promising biomarker for identifying CRC patients at high risk for liver metastases.

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OCT4 regulates epithelial-mesenchymal transition and its knockdown inhibits colorectal cancer cell migration and invasion.

Gallstone ileus (GI) is characterized by occlusion of the intestinal lumen as a result of one or more gallstones. GI is a rare complication of gallstones that occurs in 1%-4% of all cases of bowel obstruction. The mortality associated with GI ranges between 12% and 27%. Classical findings on plain abdominal radiography include: (1) pneumobilia; (2) intestinal obstruction; (3) an aberrantly located gallstone; and (4) change of location of a previously observed stone. The optimal management of acute GI is controversial and can be: (1) enterotomy with stone extraction alone; (2) enterotomy, stone extraction, cholecystectomy and fistula closure; (3) bowel resection alone; and (4) bowel resection with fistula closure. We describe a case to highlight some of the pertinent issues involved in GI management, and propose a scheme to minimize recurrent disease and postoperative complications. We conclude that GI is a rare condition affecting mainly the older population with a female predominance. The advent of computed tomography and magnetic resonance imaging has made it easier to diagnose GI. Enterotomy with stone extraction alone remains the most common surgical method because of its low incidence of complications.

Gallstone ileus: Case report and literature review

All-trans retinoic acid (atRA) is an active metabolite of vitamin A with antioxidant effects. There have been few reports on the effects of atRA on liver ischemia/reperfusion (I/R) injury. Here we have used a rat liver ischemia/ reperfusion model to analyze the protective effect of atRA. Rats were administered with different does (5—15 mg/kg/d) of atRA intraperitoneally (i.p.) for 14 d before I/R. Partial (70%) hepatic ischemia was induced by clamping the hepatic artery, portal vein, and bile duct to the left and median lobes of the liver using a vascular clamp for 60 min, followed by 24 h of reperfusion. The serum aminotransferase (ALT and AST) and hepatic pathology were used to evaluate I/R injury. The results demonstrate that atRA pretreatment attenuates liver I/R injury by inhibiting the release of malondialdehyde (MDA) and by enhancing the activity of superoxide dismutase (SOD). To gain insight into the mechanism of the SOD up-regulation by atRA, the activity of p38 mitogenactivated protein kinase (p38MAKP) and Akt was measured. The results showed that the phosphorylation of p38MAPK and Akt paralleled the expression of manganese superoxide dismutase (MnSOD). That these activities are related was demonstrated by the addition of a p38 inhibitor which markedly decreased MnSOD levels. Taken together, our data reveal that atRA can protect liver from I/R injury by increaseing MnSOD, which is associated with an increased activity of p38MAPK and Akt.

All-trans Retinoic Acid Alleviates Hepatic Ischemia/Reperfusion Injury by Enhancing Manganese Superoxide Dismutase in Rats

Triptolide alleviates hepatic ischemia/reperfusion injury by attenuating oxidative stress and inhibiting NF-κB activity in mice.

Background/Aims: Immunosuppression is one of the hallmarks of cancer; however, its molecular mechanism remains unknown. In the present study, we sought to investi

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Chuanyong Zhang

Papers

OCT4 regulates epithelial-mesenchymal transition and its knockdown inhibits colorectal cancer cell migration and invasion.

Gallstone ileus: Case report and literature review

All-trans Retinoic Acid Alleviates Hepatic Ischemia/Reperfusion Injury by Enhancing Manganese Superoxide Dismutase in Rats

Triptolide alleviates hepatic ischemia/reperfusion injury by attenuating oxidative stress and inhibiting NF-κB activity in mice.

YAP-1 Promotes Tregs Differentiation in Hepatocellular Carcinoma by Enhancing TGFBR2 Transcription.