Aspects Of Carcinogenesis Research Articles

A Reciprocal Relationship between Oxidative Stress, Antioxidants, and Cancer: A Review

Oxidative stress is a defense mechanism that occurs when there is an imbalance between the production of reactive metabolites and free radicals and the antioxidants' ability to eliminate them. Reactive metabolites are free radicals referred to as oxidants or reactive oxygen species (ROS). Cells are harmed by this imbalance, which may influence the entire body. When the intra- and extracellular environmental circumstances in cells change, ROS is essential for stimulating the corresponding signaling pathways. All aspects of carcinogenesis, including prevention and treatment, are tightly associated with reactive species, particularly ROS. Numerous tumor suppressor genes and proto-oncogenes are deregulated by ROS, which also modify several cellular signaling pathways. However, most chemotherapy drugs and even radiation therapy dramatically raise the ROS concentrations in the tumor microenvironment. Antioxidants cause programmed cell death, which is used in cancer treatment; yet people receiving chemotherapy benefit from antioxidants. Nevertheless, the exact processes underlying this anticancer action remain unclear. Many studies carried out in laboratories and on animals revealed high concentrations of exogenic antioxidants, that inhibit the forms of free radical injury linked with the formation of cancer. There haven't been many human clinical trials looking into the potential of dietary supplementation to reduce the risk of cancer development or death. Since there have been studies on the advantages and downsides of antioxidants in the treatment of cancer, several considerations need to be deemed before administering antioxidant supplements. In conclusion, little is known about the mechanism underlying antioxidant effect in cancer treatment.

The Association of pri-miR34 b/c Gene Polymorphism and Clinicopathologic Data in Breast Cancer Patients.

MiR-34b/c takes an important role in various aspects of carcinogenesis. Notably, pri miR34b/c (rs4938723) T>C polymorphism has been identified as a significant biomarker in various kinds of cancer. The objective of this study was to explore whether pri-miR34b/c rs4938723) T>C was associated with breast cancer susceptibility. Moreover, the association of pri-miR34b/c (rs4938723) T>C and clinicopathologic data, including survival outcomes, were studied in Thai breast cancer patients. DNA extracted from the blood of 100 Thai female breast cancer patients and 100 Thai healthy women were investigated for pri-miR34b/c (rs4938723) T>C polymorphism using polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP). There was no statistically significant difference between the frequency of pri miR34b/c (rs4938723) T>C genotype between Thai breast cancer patients and normal subjects. This study showed that there is no association between pri-miR34b/c (rs4938723) genotypes and breast cancer susceptibility, clinicopathologic parameters, and survival time. However, age greater than 50 and histologic grade III were the prognostic factors affecting survival in breast cancer patients (p=0.017, p=0.010, respectively). The pri-miR34b/c (rs4938723) genotypes had no association with cancer susceptibility and clinicopathologic parameters in Thai breast cancer patients. Patients with older age and patients with higher histologic grade, but not the pri miR34b/c (rs4938723) genotype, affected survival time among breast cancer patients.

Elevated pretreatment lactate dehydrogenase and albumin-to-alkaline phosphatase ratio predict poor prognosis and early treatment discontinuation in head and neck cancer patients with preexistent diabetes mellitus.

Increased serum lactate dehydrogenase (LDH) activity is considered as amarker of cellular necrosis and serves as ametabolomic diagnostic marker in several types of cancer including head and neck squamous cell carcinoma (HNSCC). LDH, an enzyme involved in the glycolytic cycle, is correlated not only with the activation of oncogenes such as HIF-α and Myc, but also with effects such as tumor proliferation and metastasis. Serum alkaline phosphatase (ALP) is amarker of cell differentiation and tumor induction. Albumin-to-alkaline phosphatase ratio (AAPR) could be an advantageous biomarker due to its easily accessible dynamics and cost-effectiveness. Elevated values of AAPR could be associated with longer overall survival (OS) in cases with solid tumors. Diabetes mellitus (DM) could influence the outcome of patients with HNSCC by contributing to insulin resistance and chronic inflammation, and by being involved in various aspects of carcinogenesis, disease progression and metastasis. However, the use of antihyperglycemic medications (metformin) can have beneficial effects by inhibiting tumor metabolic pathways. The biomarker role of LDH and AAPR in HNSCC patients with DM has been less evaluated. The purpose of the study was to assess the prognostic value of pretreatment serum lactate dehydrogenase (LDH) and albumin-to-alkaline phosphatase ratio (AAPR) in predicting the duration of non-surgical oncological treatment and glycemic control in cases of head and neck cancers patients with DM, including cases selected from the database of the oncology clinic and oncology outpatient clinic of the Craiova County Hospital. Both LDH and AAPR can be used as pre-treatment biomarkers predictive of treatment response, or prognostic tools included in complex multi-parametric models in HNC associated with DM. However, given the impact of short-term glycemic control on the LDH level, it is necessary to evaluate these biomarkers after assessing and controlling for DM, and with the recommended cut-off value set around 0.5. Due to the limited number of cases, it is necessary to validate the results in multicentric trials with alarger number of patients (Tab. 5, Ref. 50). Keywords: diabetes mellitus, HNC, LDH, AAPR, biomarkers, predictive, head and neck cancers, lactate dehydrogenase, albumin-to-alkaline phosphatase ratio.

Abstract PO1-25-01: LMTK3 promotes macrophage M2 polarisation and suppresses monocyte infiltration in breast cancer by altering the proteomic cargo of exosomes

Abstract Background: Breast cancer (BC) is a leading cause of cancer death and despite numerous treatment advancements, metastatic BC is incurable. Extracellular vesicles (EVs) are lipid-delimited particles released from cells which contain bioactive protein and nucleic acid cargo. Numerous studies have shown their importance in facilitating communication between cancer cells and the tumour microenvironment, implicating them as mediators of many aspects of carcinogenesis. EV-mediated communication between BC and the innate immune system plays a crucial role in BC progression, metastasis and the maintenance of an immunosuppressive microenvironment. LMTK3 overexpression in BC promotes therapy resistance, disease progression and invasion and metastasis, leading to a poorer prognosis in patients. Analysis of deconvoluted TCGA data indicated that LMTK3 overexpression also correlates with exclusion of M1 macrophages from the tumour microenvironment. This study aimed to explore the role of LMTK3 in EV-mediated communication between BC and immune cells. Methods EVs were collected from conditioned media of wild-type and LMTK3-overexpressing BC cells through differential ultracentrifugation, then characterised by transmission electron microscopy, nanoparticle tracking analysis, quantitative mass spectrometry and Western blotting. Monocytes were treated with EVs and proteomic and phosphoproteomic changes were analysed. 3D coculture models of BC and immune cells were used to assess monocyte and macrophage infiltration, polarisation and anti-cancer activity. Immunofluorescence and flow cytometry was used to assess macrophage polarisation. Bioinformatic analysis of TCGA datasets validated the findings in a clinical setting and the data was also validated in vivo, using syngeneic immunocompetent mouse models. Results LMTK3 overexpression in BC cells promotes the upregulation of a subpopulation of large (80-150nm) CD81+ EVs which are significantly enriched in oncogenic and immunoregulatory proteins, including LDHB, ARHGEF15, PSAT1 and HIC2. EVs from LMTK3-overexpressing but not control BC cells strongly reduce the ability of monocytes to infiltrate BC tumour spheroids and migrate through Matrigel. Proteomics analysis of the monocytes showed an enrichment in M2 polarisation proteins and a downregulation of proteins essential for migration, including S100A8, KLF13 and TRPC3. LMTK3 overexpression in BC also promotes M2 polarisation and exclusion of M1 macrophages in vivo. Summary LMTK3 overexpression in BC correlates with poor prognosis and reduced overall survival. We hypothesise that this is, in part, due to monocyte M2 polarisation and exclusion of M1 macrophages from the TME, mediated by LMTK3-dependent alterations in EV cargo, contributing to tumour immune evasion. Citation Format: Mark Samuels, William Jones, Charlotte Turner, Georgios Giamas. LMTK3 promotes macrophage M2 polarisation and suppresses monocyte infiltration in breast cancer by altering the proteomic cargo of exosomes [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-25-01.

Correctly identifying the cells of origin is essential for tailoring treatment and understanding the emergence of cancer stem cells and late metastases.

Malignancy manifests itself by deregulated growth and the ability to invade surrounding tissues or metastasize to other organs. These properties are due to genetic and/or epigenetic changes, most often mutations. Many aspects of carcinogenesis are known, but the cell of origin has been insufficiently focused on, which is unfortunate since the regulation of its growth is essential to understand the carcinogenic process and guide treatment. Similarly, the concept of cancer stem cells as cells having the ability to stop proliferation and rest in a state of dormancy and being resistant to cytotoxic drugs before "waking up" and become a highly malignant tumor recurrence, is not fully understood. Some tumors may recur after decades, a phenomenon probably also connected to cancer stem cells. The present review shows that many of these questions are related to the cell of origin as differentiated cells being long-term stimulated to proliferation.

Gastric cancer stem cell: Carcinogenesis and targeted personalized therapies of cancer stem cell

Gastric cancer (GC) is one of the most common cancers in worldwide range which ranks fifth, and it is also third most common cancerous death reason. Although there has been a decline in the rate of incidence and mortality over recent fifty years, cure for GC is extremely hard to achieve. The symptoms are not conspicuous at early stage of the GC patients usually, which is the reason GC is diagnosed at terminal stage. And it is worse that the prognosis effect is outrageously bad, the median survival times are mostly less than a year. Under this condition, prevention is the most efficient method to reduce the incidence and mortality, meanwhile, the application of newly emerged therapy should be attached importance to GC. To create accurate treatment to achieve this goal, it is necessary to comprehend the mechanism of the carcinogenesis, and mechanism of cancer development, the critical transformation points derived from those mechanism will divide the different methodology applying period. This article mainly focuses on the cancer stem cell (CSC) aspect of carcinogenesis, cancer development to inform the points which can be utilized to intervene and new therapy method.

Aptamer Conjugate-Based Ratiometric Fluorescent Probe for Precise Imaging of Therapy-Induced Cancer Senescence.

Therapy-induced cellular senescence has been increasingly recognized as a key mechanism to promote various aspects of carcinogenesis in a nonautonomous manner. Thus, real-time imaging monitoring of cellular senescence during cancer therapy is imperative not only to further elucidate its roles in cancer progression but also to provide guidance for medical management of cancer. However, it has long been a challenging task due to the lack of effective imaging molecule tools with high specificity and accuracy toward cancer senescence. Herein, we report the rational design, synthesis, and evaluation of an aptamer conjugate-based ratiometric fluorescent probe for precise imaging of therapy-induced cancer senescence. Unlike traditional senescence imaging systems, our probe targets two senescence-associated markers at both cellular and subcellular dimensions, namely, aptamer-mediated membrane marker recognition for active cell targeting and lysosomal marker-triggered ratiometric fluorescence changes of two cyanine dyes for site-specific, high-contrast imaging. Moreover, such a two-channel fluorescence response is activated after a one-step reaction and at the same location, avoiding the diffusion-caused signal decay previously encountered in dual-marker activated probes, contributing to spatiotemporally specific imaging of therapy-induced cancer senescence in living cells and three-dimensional multicellular tumor spheroids. This work may offer a valuable tool for a basic understanding of cellular senescence in cancer biology and interventions.

Impact of IL-6 and IL-1β Gene Variants on Non-small-cell Lung Cancer Risk in Egyptian Patients

Lung cancer is a serious health and life issue, with the fastest-growing incidence and fatality rates worldwide. It is now clear that inflammation is a key factor involved in all aspects of carcinogenesis, notably lung cancer development. Genetic changes, including polymorphisms in inflammatory genes, are supposed to be a significant cause of increased lung cancer risk. The main idea of this research was to disclose the linkage between both IL-6 rs1800795 and IL-1β rs16944 variants and susceptibility to non-small-cell lung cancer (NSCLC) in Egyptians. This case–control design was composed of 127 cases and 138 controls, which were genotyped using the ARMS-PCR technique. To examine the NSCLC susceptibility under various genetic models, the odds ratio (OR) and 95% confidence intervals (CIs) were determined by logistic regression. Rs1800795 of the IL-6 gene was linked to higher odds of NSCLC under the allele model (adjusted, OR 2.28; 95% CI 1.2–4.33; p = 0.011). In the genetic models, IL-6 rs1800795 elevated the odds of NSCLC, while IL-1β rs16944 decreased the odds of NSCLC. Stratification analysis showed that IL-6 rs1800795 greatly increased the NSCLC risk in females and adenocarcinoma subtypes, whereas IL-1β rs16944 largely decreased the NSCLC risk for males, patients aged < 55, and nonsmokers. Regarding clinical data, the IL-6 variant was remarkably correlated with tumor size. This work primarily established that IL-6 and IL-1β variants have a great impact on NSCLC development in the Egyptian population; thus, it may be a supportive guide for earlier NSCLC prevention.

Non-canonical functions of EZH2 in cancer.

Mutations in chromatin modifying genes frequently occur in many kinds of cancer. Most mechanistic studies focus on their canonical functions, while therapeutic approaches target their enzymatic activity. Recent studies, however, demonstrate that non-canonical functions of chromatin modifiers may be equally important and therapeutically actionable in different types of cancer. One epigenetic regulator that demonstrates such a dual role in cancer is the histone methyltransferase EZH2. EZH2 is a core component of the polycomb repressive complex 2 (PRC2), which plays a crucial role in cell identity, differentiation, proliferation, stemness and plasticity. While much of the regulatory functions and oncogenic activity of EZH2 have been attributed to its canonical, enzymatic activity of methylating lysine 27 on histone 3 (H3K27me3), a repressive chromatin mark, recent studies suggest that non-canonical functions that are independent of H3K27me3 also contribute towards the oncogenic activity of EZH2. Contrary to PRC2's canonical repressive activity, mediated by H3K27me3, outside of the complex EZH2 can directly interact with transcription factors and oncogenes to activate gene expression. A more focused investigation into these non-canonical interactions of EZH2 and other epigenetic/chromatin regulators may uncover new and more effective therapeutic strategies. Here, we summarize major findings on the non-canonical functions of EZH2 and how they are related to different aspects of carcinogenesis.

Abstract P3-08-02: Prospective Use of Feline Mammary Carcinomas to Study MiR-10b and Metastasis

Abstract Despite many advances in cancer treatment, metastatic disease is estimated to be responsible for 90% of all cancer-related deaths. Current treatments for metastatic disease target various aspects of carcinogenesis but not specifically the metastatic process, representing a major unmet clinical need. MicroRNA-10b, a small non-coding RNA, offers tremendous potential as a treatment target for metastatic disease. It is implicated in invasion, migration, and viability of metastatic cells across a variety of cancer types, and it is upregulated in metastases compared to their matched primary tumor, establishing miR-10b as a potential treatment target unique to metastatic niche. We have previously developed a therapeutic targeting miR-10b in metastases and tested it in murine models of metastatic breast cancer. This therapeutic, consisting of an anti-miR-10b antisense oligonucleotide conjugated to iron oxide-based nanoparticles, prevents metastasis and eradicates pre-existing metastases in murine breast cancer models. With an outlook to clinical translation of our approach, we seek to test our therapeutic strategy in larger animal models. Feline mammary carcinomas are considered by most to be the best large animal model for human breast cancer due to similarities such as relative age of onset, histopathology, metastatic patterns, and treatment response. To support the use of this model with our therapeutic, we investigated the characteristics of miR-10b expression in spontaneous metastatic breast cancer in companion cats. Archival blocks of matched primary tumors and metastatic lymph nodes from companion cats diagnosed with mammary carcinoma (n=9, 44%TNBC, 56%HER2+) were obtained from the tissue bank of the Michigan State University (MSU) Veterinary Diagnostic Laboratory (VDL). Tissues were analyzed for miR-10b and its target HOXD10 expression using qRT-PCR and in situ hybridization. qRT-PCR revealed that miR-10b expression was significantly upregulated in 55.5% of lymph node metastases compared to their matched primary tumor, mirroring findings in human metastatic cancer. This was validated by qRT-PCR for HOXD10 gene expression (a direct target of miR-10b), which was significantly downregulated in these metastases compared to their matched primary tumor. In situ hybridization demonstrated that miR-10b expression was increased at the invasive edge of tumors and in actively invading cells, suggesting miR-10b plays a similar role in invasion in feline breast cancer as it does in human breast cancer. Altogether, these findings support the use of feline mammary carcinomas as a model of human breast cancer and as an excellent candidate for treatment with our therapeutic. Citation Format: Alan Halim, N. Anna Savan, Paulo Vilar Saavedra, Vilma Yuzbasiyan-Gurkan, Matti Kiupel, Lorenzo Sempere, Anna Moore. Prospective Use of Feline Mammary Carcinomas to Study MiR-10b and Metastasis [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-08-02.

The Impact of BMP-4 Tissue Expression on Progression and Survival in Breast Cancer.

Bone morphogenetic protein -4 (BMP-4) plays important role in many aspects of carcinogenesis but is also involved in progression and metastasis of breast cancer where its precise role is yet to be elucidated. Since the majority of studies related to BMP-4 expression in breast cancer were conducted on cell lines of mouse models, we aimed to investigate BMP-4 tissue expression in primary human breast cancer and to correlate it with standard pathological factors for breast cancer, progression and survival. We analyzed immunohistochemical expression of BMP-4 in primary breast cancer tissue of 97 patients, correlated it with standard pathological factors for breast cancer and investigated its impact on progression and survival. BMP-4 expression was positive in 74.23% breast cancer tissue specimens. We found that hormone positive breast tumors are more likely to show BMP-4 strong granular staining pattern (p<0.01; p=0.029, respectively). There was significant association between stage group and BMP-4 expression in order that stage III breast cancer group were predominantly BMP-4 positive tumors (p=0.046). Although the most common site of distant metastases in patients with BMP-4 positive tumors were bones, we found no significant association (p>0.05). Patients with BMP-4 positive breast cancer showed longer overall and progression-free survival, but the results did not reach statistical significance (p>0.05). The results of our study in some extent can confirm the current available data and suggest that the role of BMP-4 in breast cancer is ambiguous, acting both as tumor suppressor and tumor promoter in breast cancer. For final elucidation of its impact on survival and progression in breast cancer, multicentric studies on larger sample size are required.

Novel mucoadhesive celecoxib-loaded cubosomal sponges: Anticancer potential and regulation of myeloid-derived suppressor cells in oral squamous cell carcinoma

Oral squamous-cell carcinoma (OSCC) is a widespread health problem. Myeloid-derived suppressor cells (MDSCs) are major tumor microenvironment (TME) population that govern many carcinogenesis aspects by establishing immunosuppressive milieu favoring tumor aggressiveness and treatment resistance. Cyclooxygenase-2 (COX-2) regulates MDSCs activity, hence, COX-2-selective inhibition by celecoxib (CXB) showed good anticancer effect at relatively high doses with possible subsequent cardiovascular complications. Therefore, targeted CXB delivery to MDSCs may represent a promising OSCC treatment strategy. Novel mucoadhesive-cubosomal buccal sponges were prepared for MDSCs targeting and were evaluated for their in-vitro quality attributes, ex-vivo mucoadhesion using buccal chicken-mucosa. Optimally-selected formulation showed considerable uptake by CD33+/11b+MDSCs in human OSCC cell-line (SCC-4) when quantitatively analyzed by flow-cytometry and examined using confocal-laser microscope. Optimum formulations loaded with low CXB doses (12 mg) were promoted to in-vivo studies via local application, using 4-nitroquinoline-1-oxide-induced OSCC in rats, and compared to their corresponding CXB gels. SP16 revealed the highest ability to decrease MDSC activation, recruitment and TME-immunosuppression in the isolated tumors. Consequently, SP16 exerted the greatest capacity to reduce histologic tumor grade, the OSCC-specific serum tumor markers levels, cancer hallmarks and stemness markers. CXB-loaded cubosomal sponges preferentially target MDSCs with noticeable anticancer potential and may exemplify novel mucoadhesive nanocarriers for OSCC treatment.

A Review and In Silico Analysis of Tissue and Exosomal Circular RNAs: Opportunities and Challenges in Thyroid Cancer.

Simple SummaryThyroid cancer is the most common endocrine neoplasm. Recently, knowledge of the molecular genetic changes of thyroid cancer has dramatically improved. Understanding the roles of these molecular changes in thyroid cancer tumorigenesis and progression is essential in developing a successful treatment strategy and improving disease outcomes. As a family of non-coding RNAs, circular RNAs (circRNAs) have been involved in several aspects of the physiological and pathological processes of the cells. The roles of circRNAs in cancer development and progress are evident. In the current review, we aimed to explore the clinical potential of circRNAs as potential diagnostic, prognostic, and therapeutic targets in thyroid cancer. Furthermore, screening the genome-wide circRNAs and performing functional enrichment analyses for all associated dysregulated circRNAs in thyroid cancer have been done. Given the unique advantages circRNAs have, such as superior stability, higher abundance, and presence in different body fluids, this family of non-coding RNAs could be promising diagnostic and prognostic biomarkers and potential therapeutic targets for thyroid cancer.Thyroid cancer (TC) is the most common endocrine tumor. The genetic and epigenetic molecular alterations of TC have become more evident in recent years. However, a deeper understanding of the roles these molecular changes play in TC tumorigenesis and progression is essential in developing a successful treatment strategy and improving patients’ prognoses. Circular RNAs (circRNAs), a family of non-coding RNAs, have been implicated in several aspects of carcinogenesis in multiple cancers, including TC. In the current review, we aimed to explore the clinical potential of circRNAs as putative diagnostic, prognostic, and therapeutic targets in TC. The current analyses, including genome-wide circRNA screening and functional enrichment for all deregulated circRNA expression signatures, show that circRNAs display atypical contributions, such as sponging for microRNAs, regulating transcription and translation processes, and decoying for proteins. Given their exceptional clinical advantages, such as higher stability, wider abundance, and occurrence in several body fluids, circRNAs are promising prognostic and theranostic biomarkers for TC.

STAT3 and p63 in the Regulation of Cancer Stemness.

Signal transducer and activator of transcription 3 (STAT3) is a transcription factor with many important functions in normal and transformed cells. STAT3 regulatory activities are highly complex as they are involved in various signaling pathways in different cell types under different conditions. Biologically, STAT3 is a regulative factor for normal and cancer stem cells (CSCs). Tumor protein p63 (p63), a member of the p53 protein family, is involved in these biological processes and is also physically and functionally associated with STAT3. STAT3 activation occurs during various aspects of carcinogenesis, including regulation of CSCs properties. In combination with p63, STAT3 is a possible biological marker of CSCs and a major regulator of maintenance of stemness in CSCs. We summarized the STAT3 functions and regulation and its role in CSC properties and highlight how these are affected by its associations with p63.

The Relationship between Tumor Development and Sarcoidosis in Aspects of Carcinogenesis before and after the Onset of Sarcoidosis.

Background and Objectives: It is still unclear whether sarcoidosis is likely to be associated with tumors. In addition, the use of an immune checkpoint inhibitor has been reported to initiate the onset of sarcoidosis. We retrospectively analyzed tumor development before and after the diagnosis of sarcoidosis and examined the impact of having a history of tumors on the activity or the severity of sarcoidosis. Materials and Methods: We recruited 312 consecutive cases of sarcoidosis and analyzed the tumor development before and after the onset of sarcoidosis. Results: Among them, 25 cases were diagnosed with malignant tumor after diagnosis of sarcoidosis. In the analysis of the tumor-development group after diagnosis of sarcoidosis, both serum angiotensin I-converting enzyme and mediastinal lymph node size were significantly reduced at the time of malignant tumor diagnosis compared to at the onset of sarcoidosis, indicating that the decreasing activity of sarcoidosis may be partly associated with tumor development. Furthermore, we examined 34 cases having tumor history before the onset of sarcoidosis and analyzed the effect of tumor history on the severity of sarcoidosis. Cases with a malignant tumor in the past were older and had less complicated organs of sarcoidosis than cases without malignant tumors in the past. Oral corticosteroid therapy was administrated more frequently in cases without malignant tumors in the past, indicating that the history of a malignant tumor may influence the severity of sarcoidosis. Conclusion: These results indicate that tumor development may be partly associated with the activity or severity of sarcoidosis.

MicroRNA-124 inhibits canine mammary carcinoma cell proliferation, migration and invasion by targeting CDH2

Canine mammary carcinoma (CMC) is the most common malignant tumor and the second leading cause of cancer-related mortality of dogs worldwide. MicroRNA-124 (miR-124) is an important tumor suppressor implicated in various aspects of carcinogenesis. However, the roles and mechanisms of miR-124 in CMC development remains to be determined. We used the quantitative real-time polymerase chain reaction (qRT-PCR) assay to evaluate the expression levels of miR-124 in CMC tissues obtained from 20 CMC cases and CHMm and CHMp cells. CMC cell lines were transfected with lipfactormine™2000, and the cell proliferation was measured by Cell Counting Kit-8 (CCK-8). Transwell assay were employed for evaluating the cell invasion and migration, while western blot assay was used to detect the protein changes in epithelial-mesenchymal transition (EMT) and CDH2 protein levels. The relationship between miR-124 and the 3′-untranslated region (3'-UTR) of CDH2 was predicted via bioinformatics analysis and verified by dual-luciferase reporter assay. The results revealed that miR-124 was reduced in CMC tissues and cell lines. Besides, observed high histological grade and tumor metastasis were associated with the down-regulation of miR-124 and up-regulation of CDH2. Functional analyses showed that in vitro transfection of CHMm and CHMp cells with miR-124 mimics inhibited their proliferation, migration, invasion, and EMT; however, transfection with miR-124 inhibitor resulted in the reversed effect. Besides, we showed that miR-124 directly suppressed the expression of CDH2, leading to the inhibition of CHMm cell proliferation and EMT. In conclusion, miR-124 regulates CMC tumor growth and EMT by targeting CDH2, maybe a potential therapeutic strategy against CMC.

Microbial Colonization and Inflammation as Potential Contributors to the Lack of Therapeutic Success in Oral Squamous Cell Carcinoma.

This review discusses the microenvironment of evolving and established conventional oral squamous cell carcinoma, by far the most common oral cancer. The focus of this paper is mainly on the more recent data that describe the role of microorganisms, host-microbial interactions, and in particular, the contributions of cell-surface toll-like receptors on immune system cells and on normal and malignant epithelial cells to their functions that support carcinogenesis. Because carcinomas arising at various host surfaces share much in common, additional information available from studies of other carcinomas is included in the discussion. Accumulating evidence reveals the complex toll-like receptor-mediated tumor-supporting input into many aspects of carcinogenesis via malignant cells, stromal immune cells and non-immune cells, complicating the search for effective treatments.

Determinants, mechanisms, and functional outcomes of myeloid cell diversity in cancer.

Most, if not all, aspects of carcinogenesis are influenced by the tumor microenvironment (TME), a complex architecture of cells, matrix components, soluble signals, and their dynamic interactions in the context of physical traits of the tissue. Expanding application of technologies for high-dimensional analyses with single-cell resolution has begun to decipher the contributions of the immune system to cancer progression and its implications for therapy. In this review, we will discuss the multifaceted roles of tumor-associated macrophages and neutrophils, focusing on factors that subvert tissue immune homeostasis and offer therapeutic opportunities for TME reprogramming. By performing a critical analysis of available datasets, we elaborate on diversification mechanisms and unifying principles of myeloid cell heterogeneity in human tumors.

The Clinical Significance and Mechanisms of REG4 in Human Cancers

Regenerating islet-derived type 4 (REG4), a member of the calcium-dependent lectin gene superfamily, is abnormally expressed in various cancers, such as colorectal, gastric, gallbladder, pancreatic, ovarian, prostate, and lung cancer. REG4 is associated with a relatively unfavorable prognosis and clinicopathologic features in cancers, including advanced tumor and nodal stage, histological differentiation, and liver and peritoneal metastasis. Moreover, REG4-positive cancer cells show more frequent resistance to chemoradiotherapy, especially 5-FU-based chemotherapy. REG4 participates in many aspects of carcinogenesis, including cell proliferation, apoptosis, cell cycle, invasion, metastasis, and drug resistance. The underlying mechanisms are complex and involve a series of signaling mediators and multiple pathways. Thus, REG4 may be a potential diagnostic and prognostic biomarker as well as a candidate therapeutic target in cancer patients. In this review, we systematically summarize the advances about the clinical significance, biological functions, and mechanisms underlying REG4 in cancer to provide new directions for future cancer research.

A Method for the Establishment and Characterization of Mouse Lung Adenocarcinoma Cell Lines that Mimic Traits of Human Adenocarcinomas.

Lung adenocarcinoma (LADC) is the leading cause of cancer death worldwide and is largely inflicted by carcinogens contained in tobacco smoke. The generation of cell lines mimicking traits of human LADC will profoundly advance our understanding of the pathobiology of the disease, as they offer an easy and valuable tool to study the cellular and molecular aspects of carcinogenesis. Here we describe a detailed protocol for the generation of such cell lines, following the exposure of experimental mouse strains to different tobacco carcinogens and isolation of the resulting lung tumors.