The role of activated leukocyte cell adhesion molecule (ALCAM) in cancer progression, invasion, metastasis and recurrence: A novel cancer stem cell marker and tumor-specific prognostic marker

Reciprocal Interaction with Neutrophils Facilitates Cutaneous Accumulation of Liposomes

Liposomes are versatile drug delivery systems in clinical use for cancer and many other diseases. Unfortunately, PEGylated liposomal doxorubicin (sLip/DOX) exhibits serious dose-limiting cutaneous toxicities, which are closely related to the extravascular accumulation of sLip/DOX in the dermis. No clinical interventions have been proposed for cutaneous toxicities due to the elusive transport pathways. Herein, we showed that the reciprocal interaction between liposomes and neutrophils played pivotal roles in liposome extravasation into the dermis. Neutrophils captured liposomes via the complement receptor 3 (CD11b/CD18) recognizing the fragment of complement component C3 (iC3b) deposited on the liposomal surface. Uptake of liposomes also activated neutrophils to induce CD11b upregulation and enhanced the ability of neutrophils to migrate outside the capillaries. Furthermore, inhibition of complement activation either by CRIg-L-FH (a C3b/iC3b targeted complement inhibitor) or blocking the phosphate negative charge in mPEG-DSPE could significantly reduce liposome uptake by neutrophils and alleviate the cutaneous accumulation of liposomes. These results validated the liposome extravasation pathway mediated by neutrophils and provided potential solutions to the devastating cutaneous toxicities occurring during sLip/DOX treatment.

Exploring the Potential of Antibody-Drug Conjugates in Targeting Non-small Cell Lung Cancer Biomarkers

Antibody-drug conjugates (ADCs), combining the cytotoxicity of the drug payload with the specificity of monoclonal antibodies, are one of the rapidly evolving classes of anti-cancer agents. These agents have been successfully incorporated into the treatment paradigm of many malignancies, including non-small cell lung cancer (NSCLC). The NSCLC is the most prevalent subtype of lung cancer, having a considerable burden on the cancer-related mortality and morbidity rates globally. Several ADC molecules are currently approved by the Food and Drug Administration (FDA) to be used in patients with NSCLC. However, the successful management of NSCLC patients using these agents was met with several challenges, including the development of resistance and toxicities. These shortcomings resulted in the exploration of novel therapeutic targets that can be targeted by the ADCs. This review aims to explore the recently identified ADC targets along with their oncologic mechanisms. The ADC molecules targeting these biomarkers are further discussed along with the evidence from clinical trials.

hTERT-Immortalized Mesenchymal Stem Cell-Derived Extracellular Vesicles: Large-Scale Manufacturing, Cargo Profiling, and Functional Effects in Retinal Epithelial Cells

As the economic burden associated with vision loss and ocular damage continues to rise, there is a need to explore novel treatment strategies. Extracellular vesicles (EVs) are enriched with various biological cargo, and there is abundant literature supporting the reparative and immunomodulatory properties of stem cell EVs across a broad range of pathologies. However, one area that requires further attention is the reparative effects of stem cell EVs in the context of ocular damage. Additionally, most of the literature focuses on EVs isolated from primary stem cells; the use of EVs isolated from human telomerase reverse transcriptase (hTERT)-immortalized stem cells has not been thoroughly examined. Using our large-scale EV-manufacturing platform, we reproducibly manufactured EVs from hTERT-immortalized mesenchymal stem cells (MSCs) and employed various methods to characterize and profile their associated cargo. We also utilized well-established cell-based assays to compare the effects of these EVs on both healthy and damaged retinal pigment epithelial cells. To the best of our knowledge, this is the first study to establish proof of concept for reproducible, large-scale manufacturing of hTERT-immortalized MSC EVs and to investigate their potential reparative properties against damaged retinal cells. The results from our studies confirm that hTERT-immortalized MSC EVs exert reparative effects in vitro that are similar to those observed in primary MSC EVs. Therefore, hTERT-immortalized MSCs may represent a more consistent and reproducible platform than primary MSCs for generating EVs with therapeutic potential.

Clinical significance of CD166 and HER-2 in different types of gastric cancer

INTRODUCTION

Cluster of differentiation 166 (CD166), a cancer stem cell (CSC) marker, and human epidermal growth factor receptor 2 (HER-2) are expressed in a diversity of malignancies and is associated with tumor progression. Although studies regarding the importance of CSC markers and HER-2 in gastric cancer (GC) have rapidly developed, their clinicopathological, prognosis, and diagnosis value still remain unsatisfying in GC. Therefore, the present study aims to investigate the clinical, prognostic, and diagnostic significance of CD166 and HER-2 in different histological types of GC.

MATERIALS AND METHODS

Bioinformatic analysis was applied to determine the clinical importance of CD166 and HER-2 expression based on their tissue localization in primary GC tumors and the normal adjacent samples. The expression patterns, clinical significance, prognosis, and diagnosis value of CD166 and HER-2 proteins in tissue microarrays (TMAs) of 206 GC samples, including Signet Ring Cell (SRC) and intestinal types and also 28 adjacent normal tissues were evaluated using immunohistochemistry (IHC).

RESULTS

The results indicated that the expression of CD166 (membranous and cytoplasmic) and HER-2 were significantly up-regulated in tumor cells compared to adjacent normal tissues (P = 0.010, P < 0.001, and P = 0.011, respectively). A statistically significant association was detected between a high level of membranous expression of CD166 and lymphovascular invasion (P = 0.006); We also observed a statistically significant association between high cytoplasmic expression of CD166 protein and more invasion of the subserosa (P = 0.040) in the SRC type. In contrast, there was no correlation between the expression of HER-2 and clinicopathologic characteristics. Both CD166 and HER-2 showed reasonable accuracy and high specificity as diagnostic markers.

CONCLUSION

Our results confirmed that increased membranous and cytoplasmic expression of CD166 showed clinical significance in the SRC type and is associated with the progression of the disease and more aggressive tumor behaviors. These findings can be used to assist in designating subgroups of patients that require different follow-up strategies, and also, they might be utilized as the prognostic or diagnostic biomarkers in these types of GC for prospective clinical application.

The Human Soluble NKG2D Ligand Differentially Impacts Tumorigenicity and Progression in Temporal and Model-Dependent Modes

NKG2D is an activating receptor expressed by all human NK cells and CD8 T cells. Harnessing the NKG2D/NKG2D ligand axis has emerged as a viable avenue for cancer immunotherapy. However, there is a long-standing controversy over whether soluble NKG2D ligands are immunosuppressive or immunostimulatory, originating from conflicting data generated from different scopes of pre-clinical investigations. Using multiple pre-clinical tumor models, we demonstrated that the impact of the most characterized human solid tumor-associated soluble NKG2D ligand, the soluble MHC I chain-related molecule (sMIC), on tumorigenesis depended on the tumor model being studied and whether the tumor cells possessed stemness-like properties. We demonstrated that the potential of tumor formation or establishment depended upon tumor cell stem-like properties irrespective of tumor cells secreting the soluble NKG2D ligand sMIC. Specifically, tumor formation was delayed or failed if sMIC-expressing tumor cells expressed low stem-cell markers; tumor formation was rapid if sMIC-expressing tumor cells expressed high stem-like cell markers. However, once tumors were formed, overexpression of sMIC unequivocally suppressed tumoral NK and CD8 T cell immunity and facilitated tumor growth. Our study distinguished the differential impacts of soluble NKG2D ligands in tumor formation and tumor progression, cleared the outstanding controversy over soluble NKG2D ligands in modulating tumor immunity, and re-enforced the viability of targeting soluble NKG2D ligands for cancer immunotherapy for established tumors.

Current status and future challenges of CAR-T cell therapy for osteosarcoma

Osteosarcoma, the most common bone malignancy in children and adolescents, poses considerable challenges in terms of prognosis, especially for patients with metastatic or recurrent disease. While surgical intervention and adjuvant chemotherapy have improved survival rates, limitations such as impractical tumor removal or chemotherapy resistance hinder the treatment outcomes. Chimeric antigen receptor (CAR)-T cell therapy, an innovative immunotherapy approach that involves targeting tumor antigens and releasing immune factors, has shown significant advancements in the treatment of hematological malignancies. However, its application in solid tumors, including osteosarcoma, is constrained by factors such as low antigen specificity, limited persistence, and the complex tumor microenvironment. Research on osteosarcoma is ongoing, and some targets have shown promising results in pre-clinical studies. This review summarizes the current status of research on CAR-T cell therapy for osteosarcoma by compiling recent literature. It also proposes future research directions to enhance the treatment of osteosarcoma.

The functions and regulatory pathways of S100A8/A9 and its receptors in cancers

Inflammation primarily influences the initiation, progression, and deterioration of many human diseases, and immune cells are the principal forces that modulate the balance of inflammation by generating cytokines and chemokines to maintain physiological homeostasis or accelerate disease development. S100A8/A9, a heterodimer protein mainly generated by neutrophils, triggers many signal transduction pathways to mediate microtubule constitution and pathogen defense, as well as intricate procedures of cancer growth, metastasis, drug resistance, and prognosis. Its paired receptors, such as receptor for advanced glycation ends (RAGEs) and toll-like receptor 4 (TLR4), also have roles and effects within tumor cells, mainly involved with mitogen-activated protein kinases (MAPKs), NF-κB, phosphoinositide 3-kinase (PI3K)/Akt, mammalian target of rapamycin (mTOR) and protein kinase C (PKC) activation. In the clinical setting, S100A8/A9 and its receptors can be used complementarily as efficient biomarkers for cancer diagnosis and treatment. This review comprehensively summarizes the biological functions of S100A8/A9 and its various receptors in tumor cells, in order to provide new insights and strategies targeting S100A8/A9 to promote novel diagnostic and therapeutic methods in cancers.

Periplocin Overcomes Bortezomib Resistance by Suppressing the Growth and Down-Regulation of Cell Adhesion Molecules in Multiple Myeloma

Multiple myeloma (MM) is an incurable hematological malignant disorder of bone marrow. Patients with MM receive multiple lines of chemotherapeutic treatments which often develop bortezomib (BTZ) resistance and relapse. Therefore, it is crucial to identify an anti-MM agent to overcome the BTZ resistance of MM. In this study, we screened a library of 2370 compounds against MM wild-type (ARP1) and BTZ-resistant type (ARP1-BR) cell lines and found that periplocin (PP) was the most significant anti-MM natural compound. We further investigated the anti-MM effect of PP by using annexin V assay, clonogenic assays, aldefluor assay, and transwell assay. Furthermore, RNA sequencing (RNA-seq) was performed to predict the molecular effects of PP in MM followed by verification through qRT-PCR and Western blot analysis. Moreover, ARP1 and ARP1-BR xenograft mice models of MM were established to confirm the anti-MM effects of PP invivo. The results showed that PP significantly induced apoptosis, inhibited proliferation, suppressed stemness, and reduced the cell migration of MM. The expression of cell adhesion molecules (CAMs) was suppressed upon PP treatment in vitro and in vivo. Overall, our data recommend PP as an anti-MM natural compound with the potential to overcome BTZ resistance and downregulate CAMs in MM.

CircMED12L Protects Against Hydrogen Peroxide-induced Apoptotic and Oxidative Injury in Human Lens Epithelial Cells by miR-34a-5p/ALCAM axis

PURPOSE

Cataract is the leading cause of visual impairment and reversible blindness. Despite advances in surgical removal of cataracts, cataract continues to be a leading public-health issue due to the complications after surgery. Circular RNAs (circRNAs) have been showed to be implicated in the pathophysiology of age-related cataract (ARC). Herein, this work elucidated the role and mechanism of circMED12L in the process of ARC.

METHODS

Human lens epithelial cells (HLECs) were exposed to hydrogen peroxide (H₂O₂) in experimental groups. Levels of genes and proteins were measured by qRT-PCR and western blotting. Cell growth was evaluated by Cell Counting Kit-8 (CCK-8) assay and flow cytometry, respectively. The oxidative stress was assessed by detecting the activity of malondialdehyde, catalase, and superoxide dismutase. The interaction between miR-34a-5p and circMED12L or ALCAM (activated leukocyte cell adhesion molecule) was validated using dual-luciferase reporter and RNA immunoprecipitation assays.

RESULTS

CircMED12L expression was lower in the lens epithelium of ARC patients and H₂O₂-induced HLECs compared with the normal individuals and untreated cells. Functionally, forced expression of circMED12L could alleviate H₂O₂-induced viability inhibition, as well as apoptotic and oxidative injury in HLECs. Mechanistically, circMED12L/miR-34a-5p/ALCAM constituted a feedback loop in HLECs. MiR-34a-5p was increased, while ALCAM was decreased in ARC patients and H₂O₂-induced HLECs. High expression of miR-34a-5p reversed the protective effects of circMED12L on HLECs under H₂O₂ treatment. Besides, inhibition of miR-34a-5p could repress H₂O₂-induced apoptotic and oxidative injury in HLECs, which were abolished by subsequent ALCAM knockdown.

CONCLUSION

Overexpression of circMED12L could protect against H₂O₂-induced apoptosis and oxidative stress in HLECs by miR-34a-5p/ALCAM axis.

Comparative glycoproteomics study on the surface of SKOV3 versus IOSE80 cell lines

Objective: Site- and structure-specific quantitative N-glycoproteomics study of differential cell-surface N-glycosylation of ovarian cancer SKOV3 cells with the non-cancerous ovarian epithelial IOSE80 cells as the control.

Methods: C18-RPLC-MS/MS (HCD with stepped normalized collision energies) was used to analyze the 1: 1 mixture of labeled intact N-glycopeptides from SKOV3 and IOSE80 cells, and the site- and structure-specific intact N-glycopeptide search engine GPSeeker was used to conduct qualitative and quantitative search on the obtained raw datasets.

Results: With the control of the spectrum-level false discovery rate ≤1%, 13,822 glycopeptide spectral matches coming from 2,918 N-glycoproteins with comprehensive N-glycosite and N-glycan structure information were identified; 3,733 N-glycosites and 3,754 N-glycan sequence structures were confirmed by site-determining and structure-diagnostic fragment ions, respectively. With the control of no less than two observations among the three technical replicates, fold change ≥1.5, and p-value ≤ 0.05, 746 DEPGs in SKOV3 cells relative to IOSE80 cells were quantified, where 421 were upregulated and 325 downregulated.

Conclusion: Differential cell-surface N-glycosylation of ovarian cancer SKOV3 cells were quantitatively analyzed by isotopic labeling and site- and structure-specific N-glycoproteomics. This discovery study provides putative N-glycoprotein biomarker candidates for future validation study using multiple reaction monitoring and biochemical methods.

Proteomic Analysis of HCC-1954 and MCF-7 Cell Lines Highlights Crosstalk between αv and β1 Integrins, E-Cadherin and HER-2

Overexpression of human epidermal growth factor receptor-2 (HER-2) occurs in 20% of all breast cancer subtypes, especially those that present the worst prognostic outcome through a very invasive and aggressive tumour. HCC-1954 (HER-2+) is a highly invasive, metastatic cell line, whereas MCF-7 is mildly aggressive and non-invasive. We investigated membrane proteins from both cell lines that could have a pivotal biological significance in metastasis. Membrane protein enrichment for HCC-1954 and MCF-7 proteomic analysis was performed. The samples were analysed and quantified by mass spectrometry. High abundance membrane proteins were confirmed by Western blot, immunofluorescence, and flow cytometry. Protein interaction prediction and correlations with the Cancer Genome Atlas (TCGA) patient data were conducted by bioinformatic analysis. In addition, β1 integrin expression was analysed by Western blot in cells upon trastuzumab treatment. The comparison between HCC-1954 and MCF-7 membrane-enriched proteins revealed that proteins involved in cytoskeleton organisation, such as HER-2, αv and β1 integrins, E-cadherin, and CD166 were more abundant in HCC-1954. β1 integrin membrane expression was higher in the HCC-1954 cell line resistant after trastuzumab treatment. TCGA data analysis showed a trend toward a positive correlation between HER-2 and β1 integrin in HER-2+ breast cancer patients. Differences in protein profile and abundance reflected distinctive capabilities for aggressiveness and invasiveness between HCC-1954 and MCF-7 cell line phenotypes. The higher membrane β1 integrin expression after trastuzumab treatment in the HCC-1954 cell line emphasised the need for investigating the contribution of β1 integrin modulation and its effect on the mechanism of trastuzumab resistance.

Proteome profiling of enzalutamide-resistant cell lines and serum analysis identified ALCAM as marker of resistance in castration-resistant prostate cancer

Enzalutamide (ENZA) is a frequently used therapy in metastatic castration‐resistant prostate cancer (mCRPC). Baseline or acquired resistance to ENZA have been observed, but the molecular mechanisms of resistance are poorly understood. We aimed to identify proteins involved in ENZA resistance and to find therapy‐predictive serum markers. We performed comparative proteome analyses on ENZA‐sensitive parental (LAPC4, DuCaP) and ‐resistant prostate cancer cell lines (LAPC4‐ENZA, DuCaP‐ENZA) using liquid chromatography tandem mass spectrometry (LC‐MS/MS). The top four most promising candidate markers were selected using bioinformatic approaches. Serum concentrations of selected markers (ALCAM, AGR2, NDRG1, IDH1) were measured in pretreatment samples of 72 ENZA‐treated mCRPC patients using ELISA. In addition, ALCAM serum levels were measured in 101 Abiraterone (ABI) and 100 Docetaxel (DOC)‐treated mCRPC patients' baseline samples. Results were correlated with clinical and follow‐up data. The functional role of ALCAM in ENZA resistance was assessed in vitro using siRNA. Our proteome analyses revealed 731 significantly differentially abundant proteins between ENZA‐sensitive and ‐resistant cells and our filtering methods identified four biomarker candidates. Serum analyses of these proteins revealed only ALCAM to be associated with poor patient survival. Furthermore, higher baseline ALCAM levels were associated with poor survival in ABI‐ but not in DOC‐treated patients. In LAPC4‐ENZA resistant cells, ALCAM silencing by siRNA knockdown resulted in significantly enhanced ENZA sensitivity. Our analyses revealed that ALCAM serum levels may help to identify ENZA‐ and ABI‐resistant patients and may thereby help to optimize future clinical decision‐making. Our functional analyses suggest the possible involvement of ALCAM in ENZA resistance.

Cancer stem cell marker expression and methylation status in patients with colorectal cancer

The number of individuals diagnosed with colorectal cancer (CRC) has been on an alarming upward trajectory over the past decade. In some countries, this cancer represents one of the most frequently diagnosed types of neoplasia. Therefore, it is an important demand to study the pathology underlying this disease to gain insights into the mechanism of resistance to treatment. Resistance of tumors to chemotherapy and tumor aggressiveness have been associated with a minor population of neoplastic cells, which are considered to be responsible for tumor recurrence. These types of neoplastic cells are known as cancer stem cells, which have been previously reported to serve an important role in pathogenesis of this malignant disease. Slovakia has one of the highest incidence rates of CRC worldwide. In the present study, the aim was to classify the abundance of selected stem cell markers (CD133, CD166 and Lgr5) in CRC tumors using flow cytometry. In addition, the methylation status of selected genomic regions of CRC biomarkers (ADAMTS16, MGMT, PROM1 (CD133), LGR5 and ALCAM) was investigated by pyrosequencing in a cohort of patients from Martin University Hospital, Martin, Slovakia. Samples from both primary tumors and metastatic tumors were tested. Analysis of DNA methylation in the genomic regions of indicated five CRC biomarkers was also performed, which revealed the highest levels of methylation in the A disintegrin and metalloproteinase with thrombospondin motifs 16 and O6-methyguanine-DNA methyl transferase genes, whereas the lowest levels of methylation were found in genes expressing prominin-1, leucine-rich repeat-containing G-protein-coupled receptor 5 and activated leukocyte cell adhesion molecule. Furthermore, tumor tissues from metastases showed significantly higher levels of CD133⁺ cells compared with that in primary tumors. Higher levels of CD133⁺ cells correlated with TNM stage and the invasiveness of CRC into the lymphatic system. Although relatively small number of samples was processed, CD133 marker was consider to be important marker in pathology of CRC.

ALCAM/CD166 Is Involved in the Binding and Uptake of Cancer-Derived Extracellular Vesicles

Colorectal cancer (CRC) and ovarian cancer (OvC) patients frequently develop peritoneal metastasis, a condition associated with a very poor prognosis. In these cancers, tumor-derived extracellular vesicles (EVs) cause immunosuppression, facilitate the direct attachment and invasion of cancer cells through the mesothelium, induce the conversion of peritoneal mesothelial cells (PMCs) into cancer-associated fibroblasts (CAFs) and transfer a more aggressive phenotype amongst cancer cells. Although the promoting role of EVs in CRC and OvC peritoneal metastasis is well established, the specific molecules that mediate the interactions between tumor-derived EVs and immune and non-immune target cells remain elusive. Here, we employed the SKOV-3 (ovarian adenocarcinoma) and Colo-320 (colorectal adenocarcinoma) human cell lines as model systems to study the interactions and uptake of EVs produced by ovarian carcinoma and colorectal carcinoma cells, respectively. We established that the adhesion molecule ALCAM/CD166 is involved in the interaction of cancer-derived EVs with recipient cancer cells (a process termed “EV binding” or “EV docking”) and in their subsequent uptake by these cells. The identification of ALCAM/CD166 as a molecule mediating the docking and uptake of CRC and OvC-derived EVs may be potentially exploited to block the peritoneal metastasis cascade promoted by EVs in CRC and OvC patients.

Modified Bovine Milk Exosomes for Doxorubicin Delivery to Triple-Negative Breast Cancer Cells

Biological nanoparticles, such as exosomes, offer an approach to drug delivery because of their innate ability to transport biomolecules. Exosomes are derived from cells and an integral component of cellular communication. However, the cellular cargo of human exosomes could negatively impact their use as a safe drug carrier. Additionally, exosomes have the intrinsic yet enigmatic, targeting characteristics of complex cellular communication. Hence, harnessing the natural transport abilities of exosomes for drug delivery requires predictably targeting these biological nanoparticles. This manuscript describes the use of two chemical modifications, incorporating a neuropilin receptor agonist peptide (iRGD) and a hypoxia-responsive lipid for targeting and release of an encapsulated drug from bovine milk exosomes to triple-negative breast cancer cells. Triple-negative breast cancer is a very aggressive and deadly form of malignancy with limited treatment options. Incorporation of both the iRGD peptide and hypoxia-responsive lipid into the lipid bilayer of bovine milk exosomes and encapsulation of the anticancer drug, doxorubicin, created the peptide targeted, hypoxia-responsive bovine milk exosomes, iDHRX. Initial studies confirmed the presence of iRGD peptide and the exosomes' ability to target the αvβ3 integrin, overexpressed on triple-negative breast cancer cells' surface. These modified exosomes were stable under normoxic conditions but fragmented in the reducing microenvironment created by 10 mM glutathione. In vitro cellular internalization studies in monolayer and three-dimensional (3D) spheroids of triple-negative breast cancer cells confirmed the cell-killing ability of iDHRX. Cell viability of 50% was reached at 10 μM iDHRX in the 3D spheroid models using four different triple-negative breast cancer cell lines. Overall, the tumor penetrating, hypoxia-responsive exosomes encapsulating doxorubicin would be effective in reducing triple-negative breast cancer cells' survival.

Molecular Insights into Endometrial Cancer in Mice

Pluripotent, very small embryonic-like stem cells (VSELs) and the 'progenitors' endometrial stem cells (EnSCs) along with associated molecular changes in endometrial cancer, that developed seven months after neonatal exposure to estradiol in one of the sixty mice, were studied in the present study. Endocrine disruption affected both endometrium and myometrium, there was accumulation of endometrial fluid and significant hyperplasia. Disrupted endometrial-myometrial junction resulted in mobilization of myometrial cells into endometrium and epithelial and stromal cells into myometrium suggestive of adenomyosis. Markers specific for VSELs/ EnSCs (OCT-4, NANOG, SSEA-1, SCA-1, c-KIT) showed increased expression in uterine sections and marked upregulation of corresponding transcripts (Oct-4A, Oct-4, Sox-2, Nanog, Sca-1, c-Kit) was noted in RNA extracted from both uterine tissue and stem cells enriched from endometrial fluid. Hormonal receptors (ER-α, ER-β, PR, FSHR) were upregulated in both tumor sections and in endometrial fluid. ER-β and FSHR (Fshr3) expression was prominent suggesting a major role in endometrial cancer. Cancer cells showed global hypomethylation (reduced expression of 5-methyl cytosine), reduced expression of tumor suppressor gene (PTEN) and increased expression of cancer stem cells marker (CD166) which suggested dysregulation and aberrant oncogenic events. Increased expression of PCNA, Ki67, SOX-9 suggested excessive proliferation and hyperplasia which are predominant signs of endometrial cancer. Results suggest that VSELs increase in numbers and possibly transform into cancer stem cells (co-express CD166 and OCT-4) in endometrial cancer. Expression of OCT-4, CD133, ALDHA1 and CD166 in side-population cells from human endometrial cancer samples suggests a possible role of VSELs in human endometrial cancer as well.

Elevated ALCAM Expression Associated with Endotypes and Postoperative Recurrence in Chronic Rhinosinusitis with Nasal Polyps

Background

Chronic rhinosinusitis with polyps (CRSwNP) is characterized by high heterogeneity and postoperative recurrence rate. This study aimed to explore the clinical significance of activated leukocyte cell adhesion molecule (ALCAM) in endotyping CRSwNP and predicting its recurrence.

Methods

We recruited 120 CRSwNP patients including 70 non-eosinophilic CRSwNP (neCRSwNP) and 50 eosinophilic CRSwNP (eCRSwNP) patients, and 40 healthy controls (HCs). Serum and tissue samples were collected. Serum ALCAM levels were detected by enzyme-linked immunosorbent assay (ELISA), and tissue ALCAM expression was assessed by reverse transcription-polymerase chain reaction (RT-PCR), Western blotting (WB) and immunohistochemistry (IHC). The predictive values of ALCAM expression for CRSwNP endotypes and postoperative recurrence were assessed.

Results

The serum levels of ALCAM were significantly increased in CRSwNP patients in comparison with HCs and were correlated with the peripheral eosinophil count, tissue eosinophil counts, and percentage. Multivariate analysis and receiver operating characteristic (ROC) curve highlighted that serum ALCAM levels were associated with CRSwNP endotypes. Tissue ALCAM expression was significantly enhanced in CRSwNP patients, especially in eCRSwNP patients. At the end of the study, 110 patients completed the follow-up schedule, 78 patients were categorized into the non-recurrent group, and the other 32 patients were included in the recurrent group. The serum ALCAM levels were elevated in the recurrent group compared with the non-recurrent group, and ALCAM expression in the tissue was significantly elevated. The ROC curve exhibited a high predictive ability of serum ALCAM in predicting postoperative recurrence. Logistic regression and Kaplan–Meier curves demonstrated that serum ALCAM was an independent risk factor for postoperative recurrence.

Conclusion

This is the first report suggesting that ALCAM expression was upregulated and associated with mucosal eosinophil infiltration and CRSwNP recurrence. Serum ALCAM could be a promising biomarker for distinguishing endotypes and predicting postoperative recurrence in CRwNP patients.

Antibody-drug conjugates: Resurgent anticancer agents with multi-targeted therapeutic potential

Antibody-drug conjugates (ADCs) constitute a relatively new group of anticancer agents, whose first appearance took place about two decades ago, but a renewed interest occurred in recent years, following the success of anti-cancer immunotherapy with monoclonal antibodies. Indeed, an ADC combines the selectivity of a monoclonal antibody with the cell killing properties of a chemotherapeutic agent (payload), joined together through an appropriate linker. The antibody moiety targets a specific cell surface antigen expressed by tumor cells and/or cells of the tumor microenvironment and acts as a carrier that delivers the cytotoxic payload within the tumor mass. Despite advantages in terms of selectivity and potency, the development of ADCs is not devoid of challenges, due to: i) low tumor selectivity when the target antigens are not exclusively expressed by cancer cells; ii) premature release of the cytotoxic drug into the bloodstream as a consequence of linker instability; iii) development of tumor resistance mechanisms to the payload. All these factors may result in lack of efficacy and/or in no safety improvement compared to unconjugated cytotoxic agents. Nevertheless, the development of antibodies engineered to remain inert until activated in the tumor (e.g., antibodies activated proteolytically after internalization or by the acidic conditions of the tumor microenvironment) together with the discovery of innovative targets and cytotoxic or immunomodulatory payloads, have allowed the design of next-generation ADCs that are expected to possess improved therapeutic properties. This review provides an overview of approved ADCs, with related advantages and limitations, and of novel targets exploited by ADCs that are presently under clinical investigation.

Cellular stress response to extremely low-frequency electromagnetic fields (ELF-EMF): An explanation for controversial effects of ELF-EMF on apoptosis

Impaired apoptosis is one of the hallmarks of cancer, and almost all of the non‐surgical approaches of eradicating tumour cells somehow promote induction of apoptosis. Indeed, numerous studies have stated that non‐ionizing non‐thermal extremely low‐frequency magnetic fields (ELF‐MF) can modulate the induction of apoptosis in exposed cells; however, much controversy exists in observations. When cells are exposed to ELF‐EMF alone, very low or no statistically significant changes in apoptosis are observed. Contrarily, exposure to ELF‐EMF in the presence of a co‐stressor, including a chemotherapeutic agent or ionizing radiation, can either potentiate or inhibit apoptotic effects of the co‐stressor. In our idea, the main point neglected in interpreting these discrepancies is “the cellular stress responses” of cells following ELF‐EMF exposure and its interplay with apoptosis. The main purpose of the current review was to outline the triangle of ELF‐EMF, the cellular stress response of cells and apoptosis and to interpret and unify discrepancies in results based on it. Therefore, initially, we will describe studies performed on identifying the effect of ELF‐EMF on induction/inhibition of apoptosis and enumerate proposed pathways through which ELF‐EMF exposure may affect apoptosis; then, we will explain cellular stress response and cues for its induction in response to ELF‐EMF exposure; and finally, we will explain why such controversies have been observed by different investigators.

Gastric Cancer Cell-Derived Exosomes Can Regulate the Biological Functions of Mesenchymal Stem Cells by Inducing the Expression of Circular RNA circ_0004303

As an important component of the dynamic tumor microenvironment, mesenchymal stem cells (MSCs) can interact with tumor cells to promote tumor growth. Treatment with tumor cell-derived exosomes can change the biological functions of MSCs. We want to study the mechanism by which exosomes derived from gastric cancer cells affect the biological functions of MSCs. After MSCs were treated with adenocarcinoma gastric cells (AGS) cell-derived exosomes, circular RNAs differentially expressed in MSCs were verified using existing RNA microarray results combined with quantitative real-time polymerase chain reaction (qRT-PCR). Then, circular RNAs were knocked down or overexpressed by plasmids, and the functions of circular RNAs were evaluated by Migration and invasion assay. Dual luciferase reporter assay was used to evaluate the potential mechanism of circular RNAs. After treatment with exosomes secreted by AGS, the results showed that some circular RNAs expressed by human adipose-derived MSCs showed significant differences. The elevated circ_0004303 promoted the migration and invasion of human adipose-derived MSCs in vitro. Circ_0004303 upregulated the expression of activated leukocyte cell adhesion molecule (ALCAM) by acting as a miR-148a-3p sponge, thereby enhancing the migration and invasion functions of human adipose-derived MSCs. Therefore, exosomes secreted by AGS can affect the expression of circular RNAs in human adipose-derived MSCs. Hsa_circ_0004303 can regulate the migration and invasion of human adipose-derived MSCs via the miR-148a-3P/ALCAM axis. This study suggests that tumor cells can promote the migration and homing of MSCs in adjacent tissues by secreting exosomes.

Progression and Differentiation of Alveolar Rhabdomyosarcoma Is Regulated by PAX7 Transcription Factor-Significance of Tumor Subclones

Rhabdomyosarcoma (RMS), is the most frequent soft tissue tumor in children that originates from disturbances in differentiation process. Mechanisms leading to the development of RMS are still poorly understood. Therefore, by analysis of two RMS RH30 cell line subclones, one subclone PAX7 negative, while the second one PAX7 positive, and comparison with other RMS cell lines we aimed at identifying new mechanisms crucial for RMS progression. RH30 subclones were characterized by the same STR profile, but different morphology, rate of proliferation, migration activity and chemotactic abilities in vitro, as well as differences in tumor morphology and growth in vivo. Our analysis indicated a different level of expression of adhesion molecules (e.g., from VLA and ICAM families), myogenic microRNAs, such as miR-206 and transcription factors, such as MYOD, MYOG, SIX1, and ID. Silencing of PAX7 transcription factor with siRNA confirmed the crucial role of PAX7 transcription factor in proliferation, differentiation and migration of RMS cells. To conclude, our results suggest that tumor cell lines with the same STR profile can produce subclones that differ in many features and indicate crucial roles of PAX7 and ID proteins in the development of RMS.

ALCAM/CD166: A pleiotropic mediator of cell adhesion, stemness and cancer progression

Activated Leukocyte Cell Adhesion Molecule (ALCAM/CD166) is a glycoprotein involved in homotypic and heterotypic cell adhesion. ALCAM can be proteolytically cleaved at the cell surface by metalloproteases, which generate shedding of its ectodomain. In various tumors, ALCAM is overexpressed and serves as a valuable prognostic marker of disease progression. Moreover, CD166 has been identified as a putative cancer stem cell marker in particular cancers. Herein, we summarize biochemical aspects of ALCAM, including structure, proteolytic shedding, alternative splicing, and specific ligands, and integrate this information with biological functions of this glycoprotein including cell adhesion, migration and invasion. In addition, we discuss different patterns of ALCAM expression in distinct tumor types and its contribution to tumor progression. Finally, we highlight the role of ALCAM as a cancer stem cell marker and introduce current clinical trials associated with this molecule. Future studies are needed to define the value of shed ALCAM in biofluids or ALCAM isoform expression as prognostic biomarkers in tumor progression.

Contribution of Evolutionary Selected Immune Gene Polymorphism to Immune-Related Disorders: The Case of Lymphocyte Scavenger Receptors CD5 and CD6

Pathogens are one of the main selective pressures that ancestral humans had to adapt to. Components of the immune response system have been preferential targets of natural selection in response to such pathogen-driven pressure. In turn, there is compelling evidence showing that positively selected immune gene variants conferring increased resistance to past or present infectious agents are today associated with increased risk for autoimmune or inflammatory disorders but decreased risk of cancer, the other side of the same coin. CD5 and CD6 are lymphocytic scavenger receptors at the interphase of the innate and adaptive immune responses since they are involved in both: (i) microbial-associated pattern recognition; and (ii) modulation of intracellular signals mediated by the clonotypic antigen-specific receptor present in T and B cells (TCR and BCR, respectively). Here, we review available information on CD5 and CD6 as targets of natural selection as well as on the role of CD5 and CD6 variation in autoimmunity and cancer.

A New Oxaliplatin Resistance-Related Gene Signature With Strong Predicting Ability in Colon Cancer Identified by Comprehensive Profiling

Numerous colon cancer cases are resistant to chemotherapy based on oxaliplatin and suffer from relapse. A number of survival- and prognosis-related biomarkers have been identified based on database mining for patients who develop drug resistance, but the single individual gene biomarker cannot attain high specificity and sensitivity in prognosis prediction. This work was conducted aiming to establish a new gene signature using oxaliplatin resistance-related genes to predict the prognosis for colon cancer. To this end, we downloaded gene expression profile data of cell lines that are resistant and not resistant to oxaliplatin from the Gene Expression Omnibus (GEO) database. Altogether, 495 oxaliplatin resistance-related genes were searched by weighted gene co-expression network analysis (WGCNA) and differential expression analysis. As suggested by functional analysis, the above genes were mostly enriched into cell adhesion and immune processes. Besides, a signature was built based on four oxaliplatin resistance-related genes selected from the training set to predict the overall survival (OS) by stepwise regression and least absolute shrinkage and selection operator (LASSO) Cox analysis. Relative to the low risk score group, the high risk score group had dismal OS (P < 0.0001). Moreover, the area under the curve (AUC) value regarding the 5-year OS was 0.72, indicating that the risk score was accurate in the prediction of OS for colon cancer patients (AUC >0.7). Additionally, multivariate Cox regression suggested that the signature constructed based on four oxaliplatin resistance-related genes predicted the prognosis for colon cancer cases [hazard ratio (HR), 2.77; 95% CI, 2.03–3.78; P < 0.001]. Finally, external test sets were utilized to further validate the stability and accuracy of oxaliplatin resistance-related gene signature for prognosis of colon cancer patients. To sum up, this study establishes a signature based on four oxaliplatin resistance-related genes for predicting the survival of colon cancer patients, which sheds more light on the mechanisms of oxaliplatin resistance and helps identify colon cancer cases with a dismal prognostic outcome.

Targeting Oncoimmune Drivers of Cancer Metastasis

Residual metastasis is a major cause of cancer-associated death. Recent advances in understanding the molecular basis of the epithelial-mesenchymal transition (EMT) and the related cancer stem cells (CSCs) have revealed the landscapes of cancer metastasis and are promising contributions to clinical treatments. However, this rarely leads to practical advances in the management of cancer in clinical settings, and thus cancer metastasis is still a threat to patients. The reason for this may be the heterogeneity and complexity caused by the evolutional transformation of tumor cells through interactions with the host environment, which is composed of numerous components, including stromal cells, vascular cells, and immune cells. The reciprocal evolution further raises the possibility of successful tumor escape, resulting in a fatal prognosis for patients. To disrupt the vicious spiral of tumor-immunity aggravation, it is important to understand the entire metastatic process and the practical implementations. Here, we provide an overview of the molecular and cellular links between tumors' biological properties and host immunity, mainly focusing on EMT and CSCs, and we also highlight therapeutic agents targeting the oncoimmune determinants driving cancer metastasis toward better practical use in the treatment of cancer patients.

Trailblazing perspectives on targeting breast cancer stem cells

Breast cancer (BCa) is one of the most prevalent malignant tumors affecting women's health worldwide. The recurrence and metastasis of BCa have made it a long-standing challenge to achieve remission-persistent or disease-undetectable clinical outcomes. Cancer stem cells (CSCs) possess the ability to self-renew and generate heterogeneous tumor bulk. The existence of CSCs has been found to be vital in the initiation, metastasis, therapy resistance, and recurrence of tumors across cancer types. Because CSCs grow slowly in their dormant state, they are insensitive to conventional chemotherapies; however, when CSCs emerge from their dormant state and become clinically evident, they usually acquire genetic traits that make them resistant to existing therapies. Moreover, CSCs also show evidence of acquired drug resistance in synchrony with tumor relapses. The concept of CSCs provides a new treatment strategy for BCa. In this review, we highlight the recent advances in research on breast CSCs and their association with epithelial-mesenchymal transition (EMT), circulating tumor cells (CTCs), plasticity of tumor cells, tumor microenvironment (TME), T-cell modulatory protein PD-L1, and non-coding RNAs. On the basis that CSCs are associated with multiple dysregulated biological processes, we envisage that increased understanding of disease sub-classification, selected combination of conventional treatment, molecular aberration directed therapy, immunotherapy, and CSC targeting/sensitizing strategy might improve the treatment outcome of patients with advanced BCa. We also discuss novel perspectives on new drugs and therapeutics purposing the potent and selective expunging of CSCs.

CD166 promotes cancer stem cell-like phenotype via the EGFR/ERK1/2 pathway in the nasopharyngeal carcinoma cell line CNE-2R

AIMS

The present study aimed to investigate the role and underlying mechanisms of CD166 in cancer stem cell-like (CSCs) phenotype of the radioresistant nasopharyngeal carcinoma cell CNE-2R.

MAIN METHODS

Established CD166-shRNA- CNE-2R cell line by lentivirus-mediated silencing CD166. Then, CSC-related genes mRNAs and proteins, and EGFR/ERK1/2 signaling pathway were detected using RT-PCR and western blot. Sphere formation assay was performed to evaluate the sphere formation capacity in CD166-shRNA- CNE-2R cells. The tumorigenesis ability in vivo was examined in nude mice mode.

KEY FINDINGS

Downregulation of CD166 inhibited the expression of the CSC-related genes, pEGFR and pERK in vitro and vivo. The capacity to form spheres and tumorigenesis was significantly decreased in CD166-shRNA cells. Furthermore, EGF-stimulated CD166-shRNA cells exhibited an increase in CSC-like traits by activating EGFR/ERK1/2 signaling.

SIGNIFICANCE

CD166 induced CSCs formation by activating the EGFR/ERK1/2 signaling pathway in nasopharyngeal carcinoma, which may serve as a critical molecular target for NPC therapeutic strategies.

Soluble CD5 and CD6: Lymphocytic Class I Scavenger Receptors as Immunotherapeutic Agents

CD5 and CD6 are closely related signal-transducing class I scavenger receptors mainly expressed on lymphocytes. Both receptors are involved in the modulation of the activation and differentiation cell processes triggered by clonotypic antigen-specific receptors present on T and B cells (TCR and BCR, respectively). To serve such a relevant immunomodulatory function, the extracellular region of CD5 and CD6 interacts with soluble and/or cell-bound endogenous counterreceptors but also microbial-associated molecular patterns (MAMPs). Evidence from genetically-modified mouse models indicates that the absence or blockade of CD5- and CD6-mediated signals results in dysregulated immune responses, which may be deleterious or advantageous in some pathological conditions, such as infection, cancer or autoimmunity. Bench to bedside translation from transgenic data is constrained by ethical concerns which can be overcome by exogenous administration of soluble proteins acting as decoy receptors and leading to transient “functional knockdown”. This review gathers information currently available on the therapeutic efficacy of soluble CD5 and CD6 receptor infusion in different experimental models of disease. The existing proof-of-concept warrants the interest of soluble CD5 and CD6 as safe and efficient immunotherapeutic agents in diverse and relevant pathological conditions.