Deciphering the loop of epithelial-mesenchymal transition, inflammatory cytokines and cancer immunoediting

Keratin: A potential driver of tumor metastasis

Keratins, as essential components of intermediate filaments in epithelial cells, play a crucial role in maintaining cell structure and function. In various malignant epithelial tumors, abnormal keratin expression is frequently observed and serves not only as a diagnostic marker but also closely correlates with tumor progression. Extensive research has demonstrated that keratins are pivotal in multiple stages of tumor metastasis, including responding to mechanical forces, evading the immune system, reprogramming metabolism, promoting angiogenesis, and resisting apoptosis. Here we emphasize that keratins significantly enhance the migratory and invasive capabilities of tumor cells, making them critical drivers of tumor metastasis. These findings highlight the importance of targeting keratins as a strategic approach to combat tumor metastasis, thereby advancing our understanding of their role in cancer progression and offering new therapeutic opportunities.

Unveiling the link between chronic inflammation and cancer

The highly nuanced transition from an inflammatory process to tumorigenesis is of great scientific interest. While it is well known that environmental stimuli can cause inflammation, less is known about the oncogenic modifications that chronic inflammation in the tissue microenvironment can bring about, as well as how these modifications can set off pro-tumorigenic processes. It is clear that no matter where the environmental factors come from, maintaining an inflammatory microenvironment encourages carcinogenesis. In addition to encouraging angiogenesis and metastatic processes, sustaining the survival and proliferation of malignant transformed cells, and possibly altering the efficacy of therapeutic agents, inflammation can negatively regulate the antitumoral adaptive and innate immune responses. Because chronic inflammation has multiple pathways involved in tumorigenesis and metastasis, it has gained recognition as a marker of cancer and a desirable target for cancer therapy. Recent advances in our knowledge of the molecular mechanisms that drive cancer's progression demonstrate that inflammation promotes tumorigenesis and metastasis while suppressing anti-tumor immunity. In many solid tumor types, including breast, lung, and liver cancer, inflammation stimulates the activation of oncogenes and impairs the body's defenses against the tumor. Additionally, it alters the microenvironment of the tumor. As a tactical approach to cancer treatment, these findings have underscored the importance of targeting inflammatory pathways. This review highlights the role of inflammation in cancer development and metastasis, focusing on its impact on tumor progression, immune suppression, and therapy resistance. It examines current anti-inflammatory strategies, including NSAIDs, cytokine modulators, and STAT3 inhibitors, while addressing their potential and limitations. The review emphasizes the need for further research to unravel the complex mechanisms linking inflammation to cancer progression and identify molecular targets for specific cancer subtypes.

Pentagalloyl Glucose from Bouea macrophylla Suppresses the Epithelial-Mesenchymal Transition and Synergizes the Doxorubicin-Induced Anticancer and Anti-Migration Effects in Triple-Negative Breast Cancer

Background: Triple-negative breast cancer (TNBC) represents an aggressive form of breast cancer with few available therapeutic options. Chemotherapy, particularly with drugs like doxorubicin (DOX), remains the cornerstone of treatment for this challenging subtype. However, the clinical utility of DOX is hampered by adverse effects that escalate with higher doses and drug resistance, underscoring the need for alternative therapies. This study explored the efficacy of pentagalloyl glucose (PGG), a natural polyphenol derived from Bouea macrophylla, in enhancing DOX's anticancer effects and suppressing the epithelial-mesenchymal transition (EMT) in TNBC cells. Methods: This study employed diverse methodologies to assess the effects of PGG and DOX on TNBC cells. MDA-MB231 triple-negative breast cancer cells were used to evaluate cell viability, migration, invasion, apoptosis, mitochondrial membrane potential, and protein expression through techniques including MTT assays, wound healing assays, flow cytometry, Western blotting, and immunofluorescence. Results: Our findings demonstrate that PGG combined with DOX significantly inhibits TNBC cell proliferation, migration, and invasion. PGG enhances DOX-induced apoptosis by disrupting the mitochondrial membrane potential and activating caspase pathways; consequently, the activation of caspase-3 and the cleavage of PARP are increased. Additionally, the study shows that the combination treatment upregulates ERK signaling, further promoting apoptosis. Moreover, PGG reverses DOX-induced EMT by downregulating mesenchymal markers (vimentin and β-catenin) and upregulating epithelial markers (E-cadherin). Furthermore, it effectively inhibits STAT3 phosphorylation, associated with cell survival and migration. Conclusions: These results highlight the potential of PGG as an adjuvant therapy in TNBC treatment. PGG synergizes with DOX, which potentiates its anticancer effects while mitigating adverse reactions.

The N6-methyladenosine Epitranscriptomic Landscape of Lung Adenocarcinoma

Comprehensive N6-methyladenosine (m6A) epitranscriptomic profiling of primary tumors remains largely uncharted. Here, we profiled the m6A epitranscriptome of 10 nonneoplastic lung tissues and 51 lung adenocarcinoma (LUAD) tumors, integrating the corresponding transcriptomic, proteomic, and extensive clinical annotations. We identified distinct clusters and genes that were exclusively linked to disease progression through m6A modifications. In comparison with nonneoplastic lung tissues, we identified 430 transcripts to be hypo-methylated and 222 to be hyper-methylated in tumors. Among these genes, EML4 emerged as a novel metastatic driver, displaying significant hypermethylation in tumors. m6A modification promoted the translation of EML4, leading to its widespread overexpression in primary tumors. Functionally, EML4 modulated cytoskeleton dynamics by interacting with ARPC1A, enhancing lamellipodia formation, cellular motility, local invasion, and metastasis. Clinically, high EML4 protein abundance correlated with features of metastasis. METTL3 small-molecule inhibitor markedly diminished both EML4 m6A and protein abundance and efficiently suppressed lung metastases in vivo. Significance: Our study reveals a dynamic and functional epitranscriptomic landscape in LUAD, offering a valuable resource for further research in the field. We identified EML4 hypermethylation as a key driver of tumor metastasis, highlighting a novel therapeutic strategy of targeting EML4 to prevent LUAD metastasis.

A Boolean model explains phenotypic plasticity changes underlying hepatic cancer stem cells emergence

In several carcinomas, including hepatocellular carcinoma, it has been demonstrated that cancer stem cells (CSCs) have enhanced invasiveness and therapy resistance compared to differentiated cancer cells. Mathematical-computational tools could be valuable for integrating experimental results and understanding the phenotypic plasticity mechanisms for CSCs emergence. Based on the literature review, we constructed a Boolean model that recovers eight stable states (attractors) corresponding to the gene expression profile of hepatocytes and mesenchymal cells in senescent, quiescent, proliferative, and stem-like states. The epigenetic landscape associated with the regulatory network was analyzed. We observed that the loss of p53, p16, RB, or the constitutive activation of β-catenin and YAP1 increases the robustness of the proliferative stem-like phenotypes. Additionally, we found that p53 inactivation facilitates the transition of proliferative hepatocytes into stem-like mesenchymal phenotype. Thus, phenotypic plasticity may be altered, and stem-like phenotypes related to CSCs may be easier to attain following the mutation acquisition.

Immune mediated support of metastasis: Implication for bone invasion

Bone is a common organ affected by metastasis in various advanced cancers, including lung, breast, prostate, colorectal, and melanoma. Once a patient is diagnosed with bone metastasis, the patient's quality of life and overall survival are significantly reduced owing to a wide range of morbidities and the increasing difficulty of treatment. Many studies have shown that bone metastasis is closely related to bone microenvironment, especially bone immune microenvironment. However, the effects of various immune cells in the bone microenvironment on bone metastasis remain unclear. Here, we described the changes in various immune cells during bone metastasis and discussed their related mechanisms. Osteoblasts, adipocytes, and other non-immune cells closely related to bone metastasis were also included. This review also summarized the existing treatment methods and potential therapeutic targets, and provided insights for future studies of cancer bone metastasis.

Immune Responses in Oral Papillomavirus Clearance in the MmuPV1 Mouse Model

Human papillomavirus (HPV)-induced oropharyngeal cancer now exceeds HPV-induced cervical cancer, with a noticeable sex bias. Although it is well established that women have a more proficient immune system, it remains unclear whether immune control of oral papillomavirus infections differs between sexes. In the current study, we use genetically modified mice to target CCR2 and Stat1 pathways, with the aim of investigating the role of both innate and adaptive immune responses in clearing oral papillomavirus, using our established papillomavirus (MmuPV1) infection model. Persistent oral MmuPV1 infection was detected in Rag1ko mice with T and B cell deficiencies. Meanwhile, other tested mice were susceptible to MmuPV1 infections but were able to clear the virus. We found sex differences in key myeloid cells, including macrophages, neutrophils, and dendritic cells in the infected tongues of wild type and Stat1ko mice but these differences were not observed in CCR2ko mice. Intriguingly, we also observed a sex difference in anti-MmuPV1 E4 antibody levels, especially for two IgG isotypes: IgG2b and IgG3. However, we found comparable numbers of interferon-gamma-producing CD8 T cells stimulated by E6 and E7 in both sexes. These findings suggest that males and females may use different components of innate and adaptive immune responses to control papillomavirus infections in the MmuPV1 mouse model. The observed sex difference in immune responses, especially in myeloid cells including dendritic cell (DC) subsets, may have potential diagnostic and prognostic values for HPV-associated oropharyngeal cancer.

Invasive FoxM1 phosphorylated by PLK1 induces the polarization of tumor-associated macrophages to promote immune escape and metastasis, amplified by IFITM1

BACKGROUND

Understanding the mechanism behind immune cell plasticity in cancer metastasis is crucial for identifying key regulators. Previously we found that mitotic factors regulate epithelial-mesenchymal transition, but how these factors convert to metastatic players in the tumor microenvironment (TME) is not fully understood.

METHODS

The clinical importance of mitotic factors was analyzed by heatmap analysis, a KM plot, and immunohistochemistry in lung adenocarcinoma (LUAD) patients. Immunoprecipitation, LC-MS/MS, kinase assay, and site-directed mutagenesis were performed for the interaction and phosphorylation. A tail-vein injection mouse model, Transwell-based 3D culture, microarray analysis, coculture with monocytes, and chromatin immunoprecipitation assays were used to elucidate the function of phosphorylated FoxM1 in metastasis of TME.

RESULTS

The phosphorylated FoxM1 at Ser25 by PLK1 acquires the reprogramming ability to stimulate the invasive traits in cancer and influence immune cell plasticity. This invasive form of p-FoxM1 upregulates the expression of IL1A/1B, VEGFA, and IL6 by direct activation, recruiting monocytes and promoting the polarization of M2d-like tumor-associated macrophages (TAMs). Upregulation of PD-L1 in LUAD having phosphomimetic FoxM1 facilitates immune evasion. In invasive LUAD with phosphomimetic FoxM1, IFITM1 is the most highly expressed through the activation of the STING-TBK1-IRF3 signaling, which enhances FoxM1-mediated signaling. Clinically, higher expression of FOXM1, PLK1, and IFITM1 is inversely correlated with the survival rate of advanced LUAD patients, providing a promising therapeutic strategy for the treatment of LUAD.

CONCLUSION

FoxM1-based therapy would be a potential therapeutic strategy for LUAD to reduce TAM polarization, immune escape, and metastasis, since FoxM1 functions as a genetic reprogramming factor reinforcing LUAD malignancy in the TME.

hMENA isoforms regulate cancer intrinsic type I IFN signaling and extrinsic mechanisms of resistance to immune checkpoint blockade in NSCLC

BACKGROUND

Understanding how cancer signaling pathways promote an immunosuppressive program which sustains acquired or primary resistance to immune checkpoint blockade (ICB) is a crucial step in improving immunotherapy efficacy. Among the pathways that can affect ICB response is the interferon (IFN) pathway that may be both detrimental and beneficial. The immune sensor retinoic acid-inducible gene I (RIG-I) induces IFN activation and secretion and is activated by actin cytoskeleton disturbance. The actin cytoskeleton regulatory protein hMENA, along with its isoforms, is a key signaling hub in different solid tumors, and recently its role as a regulator of transcription of genes encoding immunomodulatory secretory proteins has been proposed. When hMENA is expressed in tumor cells with low levels of the epithelial specific hMENA11a isoform, identifies non-small cell lung cancer (NSCLC) patients with poor prognosis. Aim was to identify cancer intrinsic and extrinsic pathways regulated by hMENA11a downregulation as determinants of ICB response in NSCLC. Here, we present a potential novel mechanism of ICB resistance driven by hMENA11a downregulation.

METHODS

Effects of hMENA11a downregulation were tested by RNA-Seq, ATAC-Seq, flow cytometry and biochemical assays. ICB-treated patient tumor tissues were profiled by Nanostring IO 360 Panel enriched with hMENA custom probes. OAK and POPLAR datasets were used to validate our discovery cohort.

RESULTS

Transcriptomic and biochemical analyses demonstrated that the depletion of hMENA11a induces IFN pathway activation, the production of different inflammatory mediators including IFNβ via RIG-I, sustains the increase of tumor PD-L1 levels and activates a paracrine loop between tumor cells and a unique macrophage subset favoring an epithelial-mesenchymal transition (EMT). Notably, when we translated our results in a clinical setting of NSCLC ICB-treated patients, transcriptomic analysis revealed that low expression of hMENA11a, high expression of IFN target genes and high macrophage score identify patients resistant to ICB therapy.

CONCLUSIONS

Collectively, these data establish a new function for the actin cytoskeleton regulator hMENA11a in modulating cancer cell intrinsic type I IFN signaling and extrinsic mechanisms that promote protumoral macrophages and favor EMT. These data highlight the role of actin cytoskeleton disturbance in activating immune suppressive pathways that may be involved in resistance to ICB in NSCLC.

Unpacking the Complexity of Epithelial Plasticity: From Master Regulator Transcription Factors to Non-Coding RNAs

Cellular plasticity in cancer enables adaptation to selective pressures and stress imposed by the tumor microenvironment. This plasticity facilitates the remodeling of cancer cell phenotype and function (such as tumor stemness, metastasis, chemo/radio resistance), and the reprogramming of the surrounding tumor microenvironment to enable immune evasion. Epithelial plasticity is one form of cellular plasticity, which is intrinsically linked with epithelial-mesenchymal transition (EMT). Traditionally, EMT has been regarded as a binary state. Yet, increasing evidence suggests that EMT involves a spectrum of quasi-epithelial and quasi-mesenchymal phenotypes governed by complex interactions between cellular metabolism, transcriptome regulation, and epigenetic mechanisms. Herein, we review the complex cross-talk between the different layers of epithelial plasticity in cancer, encompassing the core layer of transcription factors, their interacting epigenetic modifiers and non-coding RNAs, and the manipulation of cancer immunogenicity in transitioning between epithelial and mesenchymal states. In examining these factors, we provide insights into promising therapeutic avenues and potential anti-cancer targets.

Myo-Inositol Reverses TGF-β1-Induced EMT in MCF-10A Non-Tumorigenic Breast Cells

Epithelial-Mesenchymal Transition (EMT), triggered by external and internal cues in several physiological and pathological conditions, elicits the transformation of epithelial cells into a mesenchymal-like phenotype. During EMT, epithelial cells lose cell-to-cell contact and acquire unusual motility/invasive capabilities. The associated architectural and functional changes destabilize the epithelial layer consistency, allowing cells to migrate and invade the surrounding tissues. EMT is a critical step in the progression of inflammation and cancer, often sustained by a main driving factor as the transforming growth factor-β1 (TGF-β1). Antagonizing EMT has recently gained momentum as an attractive issue in cancer treatment and metastasis prevention. Herein, we demonstrate the capability of myo-inositol (myo-Ins) to revert the EMT process induced by TGF-β1 on MCF-10A breast cells. Upon TGF-β1 addition, cells underwent a dramatic phenotypic transformation, as witnessed by structural (disappearance of the E-cadherin-β-catenin complexes and the emergence of a mesenchymal shape) and molecular modifications (increase in N-cadherin, Snai1, and vimentin), including the release of increased collagen and fibronectin. However, following myo-Ins, those changes were almost completely reverted. Inositol promotes the reconstitution of E-cadherin-β-catenin complexes, decreasing the expression of genes involved in EMT, while promoting the re-expression of epithelial genes (keratin-18 and E-cadherin). Noticeably, myo-Ins efficiently inhibits the invasiveness and migrating capability of TGF-β1 treated cells, also reducing the release of metalloproteinase (MMP-9) altogether with collagen synthesis, allowing for the re-establishment of appropriate cell-to-cell junctions, ultimately leading the cell layer back towards a more compact state. Inositol effects were nullified by previous treatment with an siRNA construct to inhibit CDH1 transcripts and, hence, E-cadherin synthesis. This finding suggests that the reconstitution of E-cadherin complexes is an irreplaceable step in the inositol-induced reversion of EMT. Overall, such a result advocates for the useful role of myo-Ins in cancer treatment.

Tumor Microenvironmental Cytokines Drive NSCLC Cell Aggressiveness and Drug-Resistance via YAP-Mediated Autophagy

Dynamic reciprocity between cellular components of the tumor microenvironment and tumor cells occurs primarily through the interaction of soluble signals, i.e., cytokines produced by stromal cells to support cancer initiation and progression by regulating cell survival, differentiation and immune cell functionality, as well as cell migration and death. In the present study, we focused on the analysis of the functional response of non-small cell lung cancer cell lines elicited by the treatment with some crucial stromal factors which, at least in part, mimic the stimulus exerted in vivo on tumor cells by microenvironmental components. Our molecular and functional results highlight the role played by the autophagic machinery in the cellular response in terms of the invasive capacity, stemness and drug resistance of two non-small lung cancer cell lines treated with stromal cytokines, also highlighting the emerging role of the YAP pathway in the mutual and dynamic crosstalk between tumor cells and tumor microenvironment elements. The results of this study provide new insights into the YAP-mediated autophagic mechanism elicited by microenvironmental cytokines on non-small cell lung cancer cell lines and may suggest new potential strategies for future cancer therapeutic interventions.

NF-κB Activator 1 downregulation in macrophages activates STAT3 to promote adenoma-adenocarcinoma transition and immunosuppression in colorectal cancer

BACKGROUND

Adenoma-adenocarcinoma transition is a key feature of colorectal cancer (CRC) occurrence and is closely regulated by tumor-associated macrophages (TAMs) and CD8+ T cells. Here, we investigated the effect of the NF-κB activator 1 (Act1) downregulation of macrophages in the adenoma-adenocarcinoma transition.

METHODS

This study used spontaneous adenoma-developing ApcMin/+, macrophage-specific Act1-knockdown (anti-Act1), and ApcMin/+; anti-Act1 (AA) mice. Histological analysis was performed on CRC tissues of patients and mice. CRC patients' data retrieved from the TCGA dataset were analyzed. Primary cell isolation, co-culture system, RNA-seq, and fluorescence-activated cell sorting (FACS) were used.

RESULTS

By TCGA and TISIDB analysis, the downregulation of Act1 expression in tumor tissues of CRC patients negatively correlated with accumulated CD68+ macrophages in the tumor. Relative expression of EMT markers in the tumor enriched ACT1lowCD68+ macrophages of CRC patients. AA mice showed adenoma-adenocarcinoma transition, TAMs recruitment, and CD8+ T cell infiltration in the tumor. Macrophages depletion in AA mice reversed adenocarcinoma, reduced tumor amounts, and suppressed CD8+ T cell infiltration. Besides, macrophage depletion or anti-CD8a effectively inhibited metastatic nodules in the lung metastasis mouse model of anti-Act1 mice. CRC cells induced activation of IL-6/STAT3 and IFN-γ/NF-κB signaling and the expressions of CXCL9/10, IL-6, and PD-L1 in anti-Act1 macrophages. Anti-Act1 macrophages facilitated epithelial-mesenchymal-transition and CRC cells' migration via CXCL9/10-CXCR3-axis. Furthermore, anti-Act1 macrophages promoted exhaustive PD1+ Tim3+ CD8+ T cell formation. Anti-PD-L1 treatment repressed adenoma-adenocarcinoma transition in AA mice. Silencing STAT3 in anti-Act1 macrophages reduced CXCL9/10 and PD-L1 expression and correspondingly inhibited epithelial-mesenchymal-transition and CRC cells' migration.

CONCLUSIONS

Act1 downregulation in macrophages activates STAT3 that promotes adenoma-adenocarcinoma transition via CXCL9/10-CXCR3-axis in CRC cells and PD-1/PD-L1-axis in CD8+ T cells.

Mass spectrometry analysis of gut tissue in acute SIV-infection in rhesus macaques identifies early proteome alterations preceding the interferon inflammatory response

HIV infection damages the gut mucosa leading to chronic immune activation, increased morbidities and mortality, and antiretroviral therapies, do not completely ameliorate mucosal dysfunction. Understanding early molecular changes in acute infection may identify new biomarkers underlying gut dysfunction. Here we utilized a proteomics approach, coupled with flow cytometry, to characterize early molecular and immunological alterations during acute SIV infection in gut tissue of rhesus macaques. Gut tissue biopsies were obtained at 2 times pre-infection and 4 times post-infection from 6 macaques. The tissue proteome was analyzed by mass spectrometry, and immune cell populations in tissue and blood by flow cytometry. Significant proteome changes (p < 0.05) occurred at 3 days post-infection (dpi) (13.0%), 14 dpi (13.7%), 28 dpi (16.9%) and 63 dpi (14.8%). At 3 dpi, proteome changes included cellular structural activity, barrier integrity, and activation of epithelial to mesenchymal transition (EMT) (FDR < 0.0001) prior to the antiviral response at 14 dpi (IFNa/g pathways, p < 0.001). Novel EMT proteomic biomarkers (keratins 2, 6A and 20, collagen 12A1, desmoplakin) and inflammatory biomarkers (PSMB9, FGL2) were associated with early infection and barrier dysfunction. These findings identify new biomarkers preceding inflammation in SIV infection involved with EMT activation. This warrants further investigation of the role of these biomarkers in chronic infection, mucosal inflammation, and disease pathogenesis of HIV.

Tumor microenvironment and epithelial-mesenchymal transition in bladder cancer: Cytokines in the game?

Bladder cancer (BlCa) is a highly immunogenic cancer. Bacillus Calmette-Guérin (BCG) is the standard treatment for non-muscle invasive bladder cancer (NMIBC) patients and, recently, second-line immunotherapies have arisen to treat metastatic BlCa patients. Understanding the interactions between tumor cells, immune cells and soluble factors in bladder tumor microenvironment (TME) is crucial. Cytokines and chemokines released in the TME have a dual role, since they can exhibit both a pro-inflammatory and anti-inflammatory potential, driving infiltration and inflammation, and also promoting evasion of immune system and pro-tumoral effects. In BlCa disease, 70-80% are non-muscle invasive bladder cancer, while 20-30% are muscle-invasive bladder cancer (MIBC) at the time of diagnosis. However, during the follow up, about half of treated NMIBC patients recur once or more, with 5-25% progressing to muscle-invasive bladder cancer, which represents a significant concern to the clinic. Epithelial-mesenchymal transition (EMT) is one biological process associated with tumor progression. Specific cytokines present in bladder TME have been related with signaling pathways activation and EMT-related molecules regulation. In this review, we summarized the immune landscape in BlCa TME, along with the most relevant cytokines and their putative role in driving EMT processes, tumor progression, invasion, migration and metastasis formation.

Mechanisms of radioresistance and the underlying signaling pathways in colorectal cancer cells

Radiotherapy is one of the most common modalities for the treatment of a wide range of tumors, including colorectal cancer (CRC); however, radioresistance of cancer cells remains a major limitation for this treatment. Following radiotherapy, the activities of various cellular mechanisms and cell signaling pathways are altered, resulting in the development of radioresistance, which leads to therapeutic failure and poor prognosis in patients with cancer. Furthermore, even though several inhibitors have been developed to target tumor resistance, these molecules can induce side effects in nontumor cells due to low specificity and efficiency. However, the role of these mechanisms in CRC has not been extensively studied. This review discusses recent studies regarding the relationship between radioresistance and the alterations in a series of cellular mechanisms and cell signaling pathways that lead to therapeutic failure and tumor recurrence. Our review also presents recent advances in the in vitro/in vivo study models aimed at investigating the radioresistance mechanism in CRC. Furthermore, it provides a relevant biochemical basis in theory, which can be useful to improve radiotherapy sensitivity and prolong patient survival.

Mechanisms involved in cancer stem cell resistance in head and neck squamous cell carcinoma

Despite scientific advances in the Oncology field, cancer remains a leading cause of death worldwide. Molecular and cellular heterogeneity of head and neck squamous cell carcinoma (HNSCC) is a significant contributor to the unpredictability of the clinical response and failure in cancer treatment. Cancer stem cells (CSCs) are recognized as a subpopulation of tumor cells that can drive and maintain tumorigenesis and metastasis, leading to poor prognosis in different types of cancer. CSCs exhibit a high level of plasticity, quickly adapting to the tumor microenvironment changes, and are intrinsically resistant to current chemo and radiotherapies. The mechanisms of CSC-mediated therapy resistance are not fully understood. However, they include different strategies used by CSCs to overcome challenges imposed by treatment, such as activation of DNA repair system, anti-apoptotic mechanisms, acquisition of quiescent state and Epithelial-mesenchymal transition, increased drug efflux capacity, hypoxic environment, protection by the CSC niche, overexpression of stemness related genes, and immune surveillance. Complete elimination of CSCs seems to be the main target for achieving tumor control and improving overall survival for cancer patients. This review will focus on the multi-factorial mechanisms by which CSCs are resistant to radiotherapy and chemotherapy in HNSCC, supporting the use of possible strategies to overcome therapy failure.

Negative-Pressure Wound Therapy: What We Know and What We Need to Know

Negative-pressure wound therapy (NPWT) promotes wound healing by applying negative pressure to the wound surface. A quarter of a century after its introduction, NPWT has been used in various clinical conditions, although molecular biological evidence is insufficient due to delay in basic research. Here, we have summarized the history of NPWT, its mechanism of action, what is currently known about it, and what is expected to be known in the future. Particularly, attention has shifted from the four main mechanisms of NPWT to the accompanying secondary effects, such as effects on various cells, bacteria, and surgical wounds. This chapter will help the reader to understand the current status and shortcomings of NPWT-related research, which could aid in the development of basic research and, eventually, clinical use with stronger scientific evidence.

Telomere Length and Telomerase Activity in Subcutaneous and Visceral Adipose Tissues from Obese and Non-Obese Patients with and without Colorectal Cancer

To investigate the molecular mechanisms that link obesity and colorectal cancer (CRC), we analyzed parameters related to telomere function in subcutaneous and visceral adipose tissues (SAT and VAT), including subjects with and without CRC, who were classified according to their body mass index (BMI). Adipose tissues were obtained from 147 patients who had undergone surgery. A total of 66 cases corresponded to CRC patients, and 81 subjects were not affected by cancer. Relative telomere length was established by qPCR, and telomerase activity was determined by a method based on the telomeric repeat amplification protocol. Our results indicated longer telomeres in patients affected by CRC, both in SAT and VAT, when compared to the group of subjects without CRC. Tumor local invasion was associated with telomere length (TL) in SAT. Considering the BMI values, significant differences were found in the TL of both adipose tissues between subjects affected by CRC and those without cancer. Overweight subjects showed the greatest differences, with longer telomeres in the group of CRC patients, and a higher number of cases with telomerase reactivation in the VAT of subjects without cancer. In conclusion, parameters related to telomere function in adipose tissue could be considered as potential biomarkers in the evaluation of CRC and obesity.

Modeling HPV-Associated Disease and Cancer Using the Cottontail Rabbit Papillomavirus

Approximately 5% of all human cancers are attributable to human papillomavirus (HPV) infections. HPV-associated diseases and cancers remain a substantial public health and economic burden worldwide despite the availability of prophylactic HPV vaccines. Current diagnosis and treatments for HPV-associated diseases and cancers are predominantly based on cell/tissue morphological examination and/or testing for the presence of high-risk HPV types. There is a lack of robust targets/markers to improve the accuracy of diagnosis and treatments. Several naturally occurring animal papillomavirus models have been established as surrogates to study HPV pathogenesis. Among them, the Cottontail rabbit papillomavirus (CRPV) model has become known as the gold standard. This model has played a pivotal role in the successful development of vaccines now available to prevent HPV infections. Over the past eighty years, the CRPV model has been widely applied to study HPV carcinogenesis. Taking advantage of a large panel of functional mutant CRPV genomes with distinct, reproducible, and predictable phenotypes, we have gained a deeper understanding of viral–host interaction during tumor progression. In recent years, the application of genome-wide RNA-seq analysis to the CRPV model has allowed us to learn and validate changes that parallel those reported in HPV-associated cancers. In addition, we have established a selection of gene-modified rabbit lines to facilitate mechanistic studies and the development of novel therapeutic strategies. In the current review, we summarize some significant findings that have advanced our understanding of HPV pathogenesis and highlight the implication of the development of novel gene-modified rabbits to future mechanistic studies.

Unboxing the molecular modalities of mutagens in cancer

The etiology of the majority of human cancers is associated with a myriad of environmental causes, including physical, chemical, and biological factors. DNA damage induced by such mutagens is the initial step in the process of carcinogenesis resulting in the accumulation of mutations. Mutational events are considered the major triggers for introducing genetic and epigenetic insults such as DNA crosslinks, single- and double-strand DNA breaks, formation of DNA adducts, mismatched bases, modification in histones, DNA methylation, and microRNA alterations. However, DNA repair mechanisms are devoted to protect the DNA to ensure genetic stability, any aberrations in these calibrated mechanisms provoke cancer occurrence. Comprehensive knowledge of the type of mutagens and carcinogens and the influence of these agents in DNA damage and cancer induction is crucial to develop rational anticancer strategies. This review delineated the molecular mechanism of DNA damage and the repair pathways to provide a deep understanding of the molecular basis of mutagenicity and carcinogenicity. A relationship between DNA adduct formation and cancer incidence has also been summarized. The mechanistic basis of inflammatory response and oxidative damage triggered by mutagens in tumorigenesis has also been highlighted. We elucidated the interesting interplay between DNA damage response and immune system mechanisms. We addressed the current understanding of DNA repair targeted therapies and DNA damaging chemotherapeutic agents for cancer treatment and discussed how antiviral agents, anti-inflammatory drugs, and immunotherapeutic agents combined with traditional approaches lay the foundations for future cancer therapies.

Multifaceted Interplay between Hormones, Growth Factors and Hypoxia in the Tumor Microenvironment

Hormones and growth factors (GFs) are signaling molecules implicated in the regulation of a variety of cellular processes. They play important roles in both healthy and tumor cells, where they function by binding to specific receptors on target cells and activating downstream signaling cascades. The stages of tumor progression are influenced by hormones and GF signaling. Hypoxia, a hallmark of cancer progression, contributes to tumor plasticity and heterogeneity. Most solid tumors contain a hypoxic core due to rapid cellular proliferation that outgrows the blood supply. In these circumstances, hypoxia-inducible factors (HIFs) play a central role in the adaptation of tumor cells to their new environment, dramatically reshaping their transcriptional profile. HIF signaling is modulated by a variety of factors including hormones and GFs, which activate signaling pathways that enhance tumor growth and metastatic potential and impair responses to therapy. In this review, we summarize the role of hormones and GFs during cancer onset and progression with a particular focus on hypoxia and the interplay with HIF proteins. We also discuss how hypoxia influences the efficacy of cancer immunotherapy, considering that a hypoxic environment may act as a determinant of the immune-excluded phenotype and a major hindrance to the success of adoptive cell therapies.

Old and New Players of Inflammation and Their Relationship With Cancer Development

Pathogens or genotoxic agents continuously affect the human body. Acute inflammatory reaction induced by a non-sterile or sterile environment is triggered for the efficient elimination of insults that caused the damage. According to the insult, pathogen-associated molecular patterns, damage-associated molecular patterns, and homeostasis-altering molecular processes are released to facilitate the arrival of tissue resident and circulating cells to the injured zone to promote harmful agent elimination and tissue regeneration. However, when inflammation is maintained, a chronic phenomenon is induced, in which phagocytic cells release toxic molecules damaging the harmful agent and the surrounding healthy tissues, thereby inducing DNA lesions. In this regard, chronic inflammation has been recognized as a risk factor of cancer development by increasing the genomic instability of transformed cells and by creating an environment containing proliferation signals. Based on the cancer immunoediting concept, a rigorous and regulated inflammation process triggers participation of innate and adaptive immune responses for efficient elimination of transformed cells. When immune response does not eliminate all transformed cells, an equilibrium phase is induced. Therefore, excessive inflammation amplifies local damage caused by the continuous arrival of inflammatory/immune cells. To regulate the overstimulation of inflammatory/immune cells, a network of mechanisms that inhibit or block the cell overactivity must be activated. Transformed cells may take advantage of this process to proliferate and gradually grow until they become preponderant over the immune cells, preserving, increasing, or creating a microenvironment to evade the host immune response. In this microenvironment, tumor cells resist the attack of the effector immune cells or instruct them to sustain tumor growth and development until its clinical consequences. With tumor development, evolving, complex, and overlapping microenvironments are arising. Therefore, a deeper knowledge of cytokine, immune, and tumor cell interactions and their role in the intricated process will impact the combination of current or forthcoming therapies.

Cyclin E1 in Murine and Human Liver Cancer: A Promising Target for Therapeutic Intervention during Tumour Progression

Simple Summary

The cell cycle regulator Cyclin E1 is a key mediator and biomarker of liver cancer progression in mice and man independent of its canonical interacting partner Cyclin-dependent kinase 2. Over-expression of Cyclin E1 during hepatocarcinogenesis modulates several distinct biological processes such as proliferation, DNA damage response, stemness, invasion and the tumour microenvironment. Interventional depletion of Cyclin E1 in the course of liver cancer progression significantly reduces tumour burden. In contrast, the expression of Cyclin-dependent kinase 2 is dispensable for the progression of liver cancer in mice and lacked diagnostic or prognostic value in patients. Thus, specific inhibition of Cyclin E1 expression represents a promising strategy for the treatment of liver cancer.

Abstract

Cyclin E1 (CCNE1) is a regulatory subunit of Cyclin-dependent kinase 2 (CDK2) and is thought to control the transition of quiescent cells into cell cycle progression. Recently, we identified CCNE1 and CDK2 as key factors for the initiation of hepatocellular carcinoma (HCC). In the present study, we dissected the contributions of CCNE1 and CDK2 for HCC progression in mice and patients. Therefore, we generated genetically modified mice allowing inducible deletion of Ccne1 or Cdk2. After initiation of HCC, using the hepatocarcinogen diethylnitrosamine (DEN), we deleted Ccne1 or Cdk2 and subsequently analysed HCC progression. The relevance of CCNE1 or CDK2 for human HCC progression was investigated by in silico database analysis. Interventional deletion of Ccne1, but not of Cdk2, substantially reduced the HCC burden in mice. Ccne1-deficient HCCs were characterised by attenuated proliferation, impaired DNA damage response and downregulation of markers for stemness and microinvasion. Additionally, the tumour microenvironment of Ccne1-deficient mice showed a reduction in immune mediators, myeloid cells and cancer-associated fibroblasts. In sharp contrast, Cdk2 was dispensable for HCC progression in mice. In agreement with our mouse data, CCNE1 was overexpressed in HCC patients independent of risk factors, and associated with reduced disease-free survival, a common signature for enhanced chromosomal instability, proliferation, dedifferentiation and invasion. However, CDK2 lacked diagnostic or prognostic value in HCC patients. In summary, CCNE1 drives HCC progression in a CDK2-independent manner in mice and man. Therefore, interventional inactivation of CCNE1 represents a promising strategy the treatment of liver cancer.

Multifunctional Biodegradable Prussian Blue Analogue for Synergetic Photothermal/Photodynamic/Chemodynamic Therapy and Intrinsic Tumor Metastasis Inhibition

To date, various Prussian blue analogues (PBAs) have been prepared for biomedical applications due to their unique structural advantages. However, the safety and effectiveness of tumor treatment still need further exploration. This contribution reports a facile synthesis of PBA with superior tumor synergetic therapeutic effects and a detailed mechanistic evaluation of their intrinsic tumor metastasis inhibition activity. The as-synthesized PBA has a uniform cube structure with a diameter of approximately 220 nm and shows high near-infrared light (NIR) photoreactivity, photothermal conversion efficiency (41.44%), and photodynamic effect. Additionally, PBA could lead to a chemodynamic effect, which is caused by the Fenton reaction and ferroptosis. The combined therapy strategy of PBA exhibits notable tumor ablation properties due to photothermal therapy (PTT)/photodynamic therapy (PDT)/chemodynamic therapy (CDT) effects without obvious toxicity in vivo. The PBA has also shown potential as a contrast agent for magnetic resonance imaging (MRI) and photoacoustic (PA) imaging. More importantly, careful investigations reveal that PBA displays excellent biodegradation and anti-metastasis properties. Further exploration of the PBA implies that its underlying mechanism of intrinsic tumor metastasis inhibition activity can be attributed to the modulation of epithelial-mesenchymal transition (EMT) expression. The considerable potential exhibited by the as-synthesized PBA makes it an ideal candidate as a synergetic therapeutic agent for tumor treatment.

Toward personalized treatment approaches for non-small-cell lung cancer

Worldwide, lung cancer is the most common cause of cancer-related deaths. Molecular targeted therapies and immunotherapies for non-small-cell lung cancer (NSCLC) have improved outcomes markedly over the past two decades. However, the vast majority of advanced NSCLCs become resistant to current treatments and eventually progress. In this Perspective, we discuss some of the recent breakthrough therapies developed for NSCLC, focusing on immunotherapies and targeted therapies. We highlight our current understanding of mechanisms of resistance and the importance of incorporating genomic analyses into clinical studies to decipher these further. We underscore the future role of neoadjuvant and maintenance combination therapy approaches to potentially cure early disease. A major challenge to successful development of rational combination therapies will be the application of robust predictive biomarkers for clear-cut patient stratification, and we provide our views on clinical research areas that could influence how NSCLC will be managed over the coming decade.

The Role of the IL-6 Cytokine Family in Epithelial-Mesenchymal Plasticity in Cancer Progression

Epithelial–mesenchymal plasticity (EMP) plays critical roles during embryonic development, wound repair, fibrosis, inflammation and cancer. During cancer progression, EMP results in heterogeneous and dynamic populations of cells with mixed epithelial and mesenchymal characteristics, which are required for local invasion and metastatic dissemination. Cancer development is associated with an inflammatory microenvironment characterized by the accumulation of multiple immune cells and pro-inflammatory mediators, such as cytokines and chemokines. Cytokines from the interleukin 6 (IL-6) family play fundamental roles in mediating tumour-promoting inflammation within the tumour microenvironment, and have been associated with chronic inflammation, autoimmunity, infectious diseases and cancer, where some members often act as diagnostic or prognostic biomarkers. All IL-6 family members signal through the Janus kinase (JAK)–signal transducer and activator of transcription (STAT) pathway and are able to activate a wide array of signalling pathways and transcription factors. In general, IL-6 cytokines activate EMP processes, fostering the acquisition of mesenchymal features in cancer cells. However, this effect may be highly context dependent. This review will summarise all the relevant literature related to all members of the IL-6 family and EMP, although it is mainly focused on IL-6 and oncostatin M (OSM), the family members that have been more extensively studied.

Chemokines orchestrate tumor cells and the microenvironment to achieve metastatic heterogeneity

Chemokines, a subfamily of the cell cytokines, are low molecular weight proteins known to induce chemotaxis in leukocytes in response to inflammatory and pathogenic signals. A plethora of literature demonstrates that chemokines and their receptors regulate tumor progression and metastasis. With these diverse functionalities, chemokines act as a fundamental link between the tumor cells and their microenvironment. Recent studies demonstrate that the biology of chemokines and their receptor in metastasis is complex as numerous chemokines are involved in regulating site-specific tumor growth and metastasis. Successful treatment of disseminated cancer is a significant challenge. The most crucial problem for treating metastatic cancer is developing therapy regimes capable of overcoming heterogeneity problems within primary tumors and among metastases and within metastases (intralesional). This heterogeneity of malignant tumor cells can be related to metastatic potential, response to chemotherapy or specific immunotherapy, and many other factors. In this review, we have emphasized the role of chemokines in the process of metastasis and metastatic heterogeneity. Individual chemokines may not express the full potential to address metastatic heterogeneity, but chemokine networks need exploration. Understanding the interplay between chemokine-chemokine receptor networks between the tumor cells and their microenvironment is a novel approach to overcome the problem of metastatic heterogeneity. Recent advances in the understanding of chemokine networks pave the way for developing a potential targeted therapeutic strategy to treat metastatic cancer.

Inflammation-Induced Tumorigenesis and Metastasis

Inflammation, especially chronic inflammation, plays a pivotal role in tumorigenesis and metastasis through various mechanisms and is now recognized as a hallmark of cancer and an attractive therapeutic target in cancer. In this review, we discuss recent advances in molecular mechanisms of how inflammation promotes tumorigenesis and metastasis and suppresses anti-tumor immunity in various types of solid tumors, including esophageal, gastric, colorectal, liver, and pancreatic cancer as well as hematopoietic malignancies.

Upregulation of TMEM45A Promoted the Progression of Clear Cell Renal Cell Carcinoma in vitro

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is the most common and aggressive type of primary kidney cancer worldwide. Transmembrane protein 45A (TMEM45A) has been reported to be closely associated with the progression of several cancers. However, the role of TMEM45A in ccRCC remains unclear. Our study intended to explore the potential role of TMEM45A in ccRCC.

METHODS

Data on the expression of TMEM45A were obtained from multiple databases, including UCSC, GEPIA2, Oncomine and TIMER. Real-world samples of ccRCC and paired normal renal tissues were used to confirm the information obtained from the databases. In addition, the prognostic value of TMEM45A was evaluated. Loss-of-function assays were performed using TMEM45A-targeting lentivirus to evaluate the biological role of TMEM45A in renal cancer cells. Gene set enrichment analysis (GSEA) was performed to investigate the potential molecular mechanisms.

RESULTS

TMEM45A was significantly overexpressed in patients with ccRCC and correlated with poor overall survival and disease-free survival. In addition, the expression of TMEM45A was closely associated with various clinicopathological parameters such as histological grade and TNM stage. Knockdown of TMEM45A inhibited the proliferation and migration and promoted the apoptosis of ccRCC cells in vitro. The results of the GSEA suggested that TMEM45A was potentially involved in the promotion of epithelial-mesenchymal transition (EMT) and inflammatory response in ccRCC.

CONCLUSION

TMEM45A was overexpressed and associated with poor survival and acted as a tumour promoter in ccRCC; therefore, might be a potential prognostic marker and therapeutic target.

Flow cytometry detection of cell type-specific expression of programmed death receptor ligand-1 (PD-L1) in colorectal cancer specimens

Aim

PD-1/PD-L1 blockade therapy is now widely used for the treatment of advanced malignancies. Although PD-L1 is known to be expressed by various host cells as well as tumor cells, the role of PD-L1 on non-malignant cells and its clinical significance is unknown. We evaluated cell type-specific expression of PD-L1 in colorectal cancer (CRC) specimens using multicolor flow cytometry.

Methods

Single cell suspensions were made from 21 surgically resected CRC specimens, and immunostained with various mAbs conjugated with different fluorescent dyes. Tumor cells, stromal cells, and immune cells were identified as CD326(+), CD90(+) and CD45(+) phenotype, respectively. CD11b(+) myeloid cells, CD19(+) B cells and CD4(+) or CD8(+) T cells were also stained in different samples, and their frequencies in the total cell population and the ratio of PD-L1(+) cells to each phenotype were determined.

Results

PD-L1 was expressed by all the cell types. The ratio of PD-L1(+) cells to CD326(+) tumor cells was 19.1% ± 14.0%, lower than those for CD90(+) stromal cells (39.6% ± 16.0%) and CD11b(+) myeloid cells (31.9% ± 14.3%). The ratio of PD-L1(+) cells in tumor cells correlated strongly with the ratio in stromal cells, while only weakly with that in myeloid cells. Tumor cells were divided into two populations by CD326 expression levels, and the PD-L1 positive ratios were inversely correlated with the rate of CD326 highly expressing cells as well as mean fluorescein intensity of CD326 in tumor cells, while positively correlated with the frequencies of stromal cells or myeloid cells in CRC.

Conclusion

PD-L1 is differentially expressed on various cell types in CRC. PD-L1 on tumor cells may be upregulated together with CD326 downregulation in the process of epithelial mesenchymal transition. Quantification of cell type-specific expression of PD-L1 using multicolor flow cytometry may provide useful information for the immunotherapy of solid tumors.

Development of Cancer in Patients With Heart Failure: How Systemic Inflammation Can Lay the Groundwork

In the last decade, cardiologists and oncologists have provided clinical and experimental evidence that cancer, and not only chemotherapeutic agents, can cause detrimental effects on heart structure and function, a consequence that has serious clinical implications for patient management. In parallel, the intriguing idea that heart failure (HF) may be an oncogenic condition has also received growing attention. A number of epidemiological and clinical studies have reported that patients with HF have a higher risk of developing cancer. Chronic low-grade systemic inflammation has been proposed as a major pathophysiological process linking the failing heart to the multi-step process of carcinogenesis. According to this view, pro-inflammatory mediators secreted by the damaged heart generate a favorable milieu that promotes tumor development and accelerates malignant transformation. HF-associated inflammation synergizes with tumor-associated inflammation, so that over time it is no longer possible to distinguish the effects of one or the other. Experimental studies have just begun to search for the molecular effectors of this process, with the ultimate goal that of identifying mechanisms suitable for anti-cancer target therapy to reduce the risk of incident cancer in patients already affected by HF. In this review we critically discuss strengths and limitations of clinical and experimental studies that support a causal relationship between HF and cancer, and focus on HF-associated inflammation, cardiokines and their endocrine functions linking one and the other disease.

Effects of a gestational level of estradiol on cellular transition, migration, and inflammation in cervical epithelial and stromal cells

PROBLEM

Estrogen (E2) is one of the main steroid hormones associated with pregnancy and parturition. High levels of E2 increase uterine contractions, promote fetal membrane weakening, and induce degradation of the cervical extracellular matrix (ECM). Current evidence supports the role of E2 in epithelial-to-mesenchymal transition (EMT) and inflammation in different cell types; however, its effects on the cellular components of the cervix are still unknown.

METHOD OF STUDY

In this study, we assessed the effects of gestational levels of E2 in: (a) the cellular transition of endocervical epithelial cells (EEC) and cervical stromal cells (CSC) in vitro using immunocytochemical staining and Western blot analyses for EMT markers (cytokeratin-18, E-cadherin, N-cadherin, SNAIL, and vimentin); (b) cell migration using in vitro scratch assays; (c) inflammatory cytokine (interleukin 1β and TNF-α) and MMP9 production under untreated and lipopolysaccharide (LPS)-treated conditions using immunoassays.

RESULTS

E2 treatment and co-treatment with LPS as a proxy for infection maintained the metastate of EEC (expression of both cytokeratin and vimentin) and the mesenchymal state of CSC. E2 delayed wound healing, which mimics the tissue remodeling process, in EEC and CSC. E2 led to persistently elevated levels of vimentin throughout the EEC wound healing process. E2 did not affect inflammatory cytokine production by EEC and CSC but increased MMP9 production by EEC.

CONCLUSION

Collectively, these results show that third trimester levels of E2 may permit localized inflammation, increase MMP-9 production, and cause an EMT-mediated impairment of the remodeling process in the cervix in vitro. These data suggest a potential contribution of E2 in cervical ripening.

Decoding cancer's camouflage: epithelial-mesenchymal plasticity in resistance to immune checkpoint blockade

Epithelial-mesenchymal plasticity (EMP) of cancer cells contributes to cancer cell heterogeneity, and it is well established that EMP is a critical determinant of acquired resistance to cancer treatment modalities including radiation therapy, chemotherapy, and targeted therapies. Here, we aimed to explore how EMP contributes to cancer cell camouflage, allowing an ever-changing population of cancer cells to pass under the radar of our immune system and consequently compromise the effect of immune checkpoint blockade therapies. The ultimate clinical benefit of any combination regimen is evidenced by the sum of the drug-induced alterations observed in the variety of cellular populations composing the tumor immune microenvironment. The finely-tuned molecular crosstalk between cancer and immune cells remains to be fully elucidated, particularly for the spectrum of malignant cells along the epithelial to mesenchymal axis. High-dimensional single cell analyses of specimens collected in ongoing clinical studies is becoming a key contributor to our understanding of these interactions. This review will explore to what extent targeting EMP in combination with immune checkpoint inhibition represents a promising therapeutic avenue within the overarching strategy to reactivate a halting cancer-immunity cycle and establish a robust host immune response against cancer cells. Therapeutic strategies currently in clinical development will be discussed.

Hepatitis B virus X protein enhances the development of liver fibrosis and the expression of genes associated with epithelial-mesenchymal transitions and tumor progenitor cells

The hepatitis B virus X protein (HBx) has pleiotropic biological effects, which underlies its potential role in cell transformation. However, its involvement in hepatic fibrosis remains unclear. In this study, we wanted to clarify, in vivo, the role of HBx protein in the development of liver fibrosis. Mice transgenic for the full-length HBx (FL-HBx) were used. To create liver fibrosis, FL-HBx transgenic and control mice were chronically exposed to carbon tetrachloride (CCl4). Modulation of the expression of proteins involved in matrix remodeling, hepatic metabolism and epithelial-mesenchymal transition (EMT) were investigated. In transgenic mice, FL-HBx expression potentiates CCl4-induced liver fibrosis with increased expression of proteins involved in matrix remodeling (Collagen1a, α-Sma, PdgfR-β, MMP-13). In FL-HBx transgenic mice, an increase in EMT was observed with a higher transcription of two inflammatory cytokines (TNF-α and TGF-β) and a decrease of glutamine synthetase expression level. This was associated with a sustained cell cycle and hepatocyte polyploidy alteration consistent with p38 and ERK1/2 overactivation, increase of PLK1 transcription, accumulation of SQSTM1/p62 protein and increase expression of Beclin-1. This correlates with a higher expression of tumor progenitor cell markers (AFP, Ly6D and EpCam), indicating a higher risk of progression from fibrosis to hepatocellular carcinoma (HCC) in the presence of FL-HBx protein. In conclusion, our results show that FL-HBx protein enhances the development of liver fibrosis and contributes to the progression of liver disease from chronic hepatitis to HCC.

CSC Radioresistance: A Therapeutic Challenge to Improve Radiotherapy Effectiveness in Cancer

Radiotherapy (RT) is a modality of oncologic treatment that can be used to treat approximately 50% of all cancer patients either alone or in combination with other treatment modalities such as surgery, chemotherapy, immunotherapy, and therapeutic targeting. Despite the technological advances in RT, which allow a more precise delivery of radiation while progressively minimizing the impact on normal tissues, issues like radioresistance and tumor recurrence remain important challenges. Tumor heterogeneity is responsible for the variation in the radiation response of the different tumor subpopulations. A main factor related to radioresistance is the presence of cancer stem cells (CSC) inside tumors, which are responsible for metastases, relapses, RT failure, and a poor prognosis in cancer patients. The plasticity of CSCs, a process highly dependent on the epithelial–mesenchymal transition (EMT) and associated to cell dedifferentiation, complicates the identification and eradication of CSCs and it might be involved in disease relapse and progression after irradiation. The tumor microenvironment and the interactions of CSCs with their niches also play an important role in the response to RT. This review provides a deep insight into the characteristics and radioresistance mechanisms of CSCs and into the role of CSCs and tumor microenvironment in both the primary tumor and metastasis in response to radiation, and the radiobiological principles related to the CSC response to RT. Finally, we summarize the major advances and clinical trials on the development of CSC-based therapies combined with RT to overcome radioresistance. A better understanding of the potential therapeutic targets for CSC radiosensitization will provide safer and more efficient combination strategies, which in turn will improve the live expectancy and curability of cancer patients.

Cytokines and Chemokines as Mediators of Prostate Cancer Metastasis

The consequences of prostate cancer metastasis remain severe, with huge impact on the mortality and overall quality of life of affected patients. Despite the convoluted interplay and cross talk between various cell types and secreted factors in the metastatic process, cytokine and chemokines, along with their receptors and signaling axis, constitute important factors that help drive the sequence of events that lead to metastasis of prostate cancer. These proteins are involved in extracellular matrix remodeling, epithelial-mesenchymal-transition, angiogenesis, tumor invasion, premetastatic niche creation, extravasation, re-establishment of tumor cells in secondary organs as well as the remodeling of the metastatic tumor microenvironment. This review presents an overview of the main cytokines/chemokines, including IL-6, CXCL12, TGFβ, CXCL8, VEGF, RANKL, CCL2, CX3CL1, IL-1, IL-7, CXCL1, and CXCL16, that exert modulatory roles in prostate cancer metastasis. We also provide extensive description of their aberrant expression patterns in both advanced disease states and metastatic sites, as well as their functional involvement in the various stages of the prostate cancer metastatic process.

Dichloroacetate prevents TGFβ-induced epithelial-mesenchymal transition of retinal pigment epithelial cells

Proliferative retinopathies are associated with formation of fibrous epiretinal membranes. At present, there is no pharmacological intervention for the treatment of retinopathies. Cytokines such as TGFβ are elevated in the vitreous humor of the patients with proliferative vitro-retinopathy, diabetic retinopathy and age-related macular degeneration. TGFβ isoforms lead to epithelial-mesenchymal transition (EMT) or trans-differentiation of the retinal pigment epithelial (RPE) cells. PI3K/Akt and MAPK/Erk pathways play important roles in the EMT of RPE cells. Therefore, inhibition of EMT by pharmacological agents is an important therapeutic strategy in retinopathy. Dichloroacetate (DCA) is shown to prevent proliferation and EMT of cancer cell lines but its effects are not explored on the prevention of EMT of RPE cells. In the present study, we have investigated the role of DCA in preventing TGFβ2 induced EMT of RPE cell line, ARPE-19. A wound-healing assay was utilized to detect the anti-EMT effect of DCA. The expressions of EMT and cell adhesion markers were carried out by immunofluorescence, western blotting, and quantitative real-time PCR. The expression of MAPK/Erk and PI3K/Akt pathway members was carried out using western blotting. We found that TGFβ2 exposure leads to an increase in the wound healing response, expression of EMT markers (Fibronectin, Collagen I, N-cadherin, MMP9, S100A4, α-SMA, Snai1, Slug) and a decrease in the expression of cell adhesion/epithelial markers (ZO-1, Connexin 43, E-cadherin). These changes were accompanied by the activation of PI3K/Akt and MAPK/Erk pathways. Simultaneous exposure of DCA along with TGFβ2 significantly inhibited wound healing response, expression of EMT markers and cell adhesion/epithelial markers. Furthermore, DCA and TGFβ2 effectively attenuated the activation of MAPK/Erk/JNK and PI3K/Akt/GSK3β pathways. Our results demonstrate that DCA has a strong anti-EMT effect on the ARPE-19 cells and hence can be utilized as a therapeutic agent in the prevention of proliferative retinopathies.

Relevance of immune cell and tumor microenvironment imaging in the new era of immunotherapy

Tumor-infiltrating immune cells play a key role against cancer. However, malignant cells are able to evade the immune response and establish a very complex balance in which different immune subtypes may drive tumor progression, metastatization and resistance to therapy. New immunotherapeutic approaches aim at restoring the natural balance and increase immune response against cancer by different mechanisms. The complexity of these interactions and the heterogeneity of immune cell subpopulations are a real challenge when trying to develop new immunotherapeutics and evaluate or predict their efficacy in vivo. To this purpose, molecular imaging can offer non-invasive diagnostic tools like radiopharmaceuticals, contrast agents or fluorescent dyes. These agents can be useful for preclinical and clinical purposes and can overcome [18F]FDG limitations in discriminating between true-progression and pseudo-progression. This review provides a comprehensive overview of immune cells involved in microenvironment, available immunotherapies and imaging agents to highlight the importance of new therapeutic biomarkers and their in vivo evaluation to improve the management of cancer patients.

Permissive State of EMT: The Role of Immune Cell Compartment

The Epithelial to Mesenchymal Transition (EMT) type 3 is a reversible dynamic process recognized as a major determinant of the metastatic event, although many questions regarding its role throughout this process remain unanswered. The ability of cancer cells to migrate and colonize distant organs is a key aspect of tumor progression and evolution, requiring constant tumor cells and tumor microenvironment (TME) changes, as well as constant changes affecting the cross-talk between the two aforementioned compartments. Alterations affecting tumor cells, such as transcription factors, trans-membrane receptors, chromatin remodeling complexes and metabolic pathways, leading to the disappearance of the epithelial phenotype and concomitant gaining of the undifferentiated mesenchymal phenotype are undoubtedly major players of the EMT process. However, several lines of evidence point out toward a more critical role of TME composition in creating an “EMT-permissive state.” The “EMT-permissive state” consists in changes affecting physical and biochemical properties (i.e., stiffness and/or hypoxia) as well as changes of the TME cellular component (i.e., immune-cell, blood vessel, lymphatic vessels, fibroblasts, and fat cells) that favor and induce the epithelial mesenchymal transition. In this mini review, we will discuss the role of the tumor microenvironment cellular component that are involved in supporting the EMT, with particular emphasis on the immune-inflammatory cells component.

Resveratrol Suppresses Prostate Cancer Epithelial Cell Scatter/Invasion by Targeting Inhibition of Hepatocyte Growth Factor (HGF) Secretion by Prostate Stromal Cells and Upregulation of E-cadherin by Prostate Cancer Epithelial Cells

Cancer mortality is primarily attributed to metastasis and the resulting compromise of organs secondary to the initial tumor site. Metastasis is a multi-step process in which the tumor cells must first acquire a migratory phenotype and invade through the surrounding tissue for spread to distant organs in the body. The ability of malignant cells to migrate and breach surrounding tissue/matrix barriers is among the most daunting challenges to disease management for men in the United States diagnosed with prostate cancer (CaP), especially since, at diagnosis, a high proportion of patients already have occult or clinically-detectable metastasis. The interaction between hepatocyte growth factor (HGF) secreted by the stroma, with its receptor c-Met located in the epithelium, must occur for epithelial CaP cells to become migratory. We studied the effects of grape-derived phytochemical resveratrol on the transition of epithelial tumor cells from sedentary to a mobile, penetrant phenotype. A time lapse microscopy assay was used to monitor the acquisition of the migratory phenotype by resveratrol. The results show that resveratrol inhibits HGF-mediated interaction between the stroma and epithelium and suppresses epithelial CaP cell migration by attenuating the control of epithelial-to-mesenchymal transition (EMT).

Combined Snail and E-cadherin Predicts Overall Survival of Cervical Carcinoma Patients: Comparison Among Various Epithelial-Mesenchymal Transition Proteins

Background

Activation of Snail and synergistic loss of E-cadherin are hallmark features of the epithelial-mesenchymal transition (EMT), which contributes to the metastasis phenotype of epithelial cancer cells. However, the prognostic impact of Snail and of its combination with E-cadherin and with other EMT prognostic markers has not yet been systematically studied in cervical carcinoma. This study aimed to explore the prognostic value of combined Snail and E-cadherin in patients with cervical carcinoma and compared it to the prognostic value of other EMT prognostic markers.

Methods

We retrospectively identified every initial diagnosis of cervical carcinoma among 203 patients treated at our hospital in China from January 2008 to March 2013. We examined the prognostic significance of Snail and other EMT protein markers, such as E-cadherin, Slug, ZEB1, Twist, Vimentin, and Survivin, by univariate and multivariate survival analyses.

Results

Multivariate analyses showed that Snail and E-cadherin were significant biomarkers for overall survival (OS) in cervical carcinoma patients (HR, hazard ratio = 1.744, P = 0.036 and HR = 1.738, P = 0.047; respectively). Moreover, a combined index including Snail and E-cadherin showed enhanced prognostic value compared to that of Snail or E-cadherin alone. The present data demonstrate that Snail shows a negative correlation with E-cadherin (P < 0.001). High Snail expression and low E-cadherin expression were also more common in high tumor stages (P = 0.044 and P = 0.036; respectively), and lymph node metastasis (both P < 0.001). Moreover, Snail was a superior prognosis factor compared to Slug, ZEB1, Twist, Vimentin, and Survivin in cervical carcinoma.

Conclusion

Based on our results, Snail and E-cadherin may be considered as independent prognosis markers, and the combination of Snail and E-cadherin might improve the OS prediction accuracy for patients with cervical carcinoma.

Anticancer effect of Limonin against benzo(a)pyrene-induced lung carcinogenesis in Swiss albino mice and the inhibition of A549 cell proliferation through apoptotic pathway

The main purpose of the current study is to reveal the anticancer action of limonin against benzo(a)pyrene [B(a)P]-treated lung carcinogenesis in Swiss albino mice and A549 lung cancer cells. B(a)P was orally supplemented (50 mg/kg body weight) twice a week for four weeks induction of lung cancer in mice. The lung weight, body weight, incidence of tumor, lipid peroxidation, carcinoembryonic antigen (CEA), enzymatic and nonenzymatic antioxidants (superoxide dismutase, GPx, glutathione, glutathione reductase, catalase, and glutathione S-transferase), serum marker enzymes (aryl hydroxylase, lactate dehydrogenase, 5'-nucleotidases, and γ-glutamyl transpeptidase), and inflammatory mediators (interleukin-1β, interleukin-6, and tumor necrosis factor-α) were estimated. Moreover, a histopathological study of lung tissues was supported by the biochemical analysis. Furthermore, the anticancer activity of limonin on A549 cells was measured by cell viability, production of reactive oxygen species (ROS), apoptotic morphological changes by AO/EtBr staining. Additionally, the status of apoptosis protein (caspase-9 and -3) expressions was analyzed by the colorimetric analysis. B(a)P-induced mice showed increased lipid peroxidation, CEA, serum marker enzymes and inflammatory cytokines levels with simultaneously decreased in the nonenzymatic and enzymatic antioxidants levels. Limonin supplements significantly reverted back to all these changes in this manner, showing the efficiency of anticancer effect. Furthermore, our in vitro study also supported the anticancer effect of the treatment of limonin-enhanced apoptosis by loss of cell viability, improved ROS production, apoptotic morphological changes, and apoptosis protein expression were analyzed. Overall, these results suggest the anticancer potential of limonin against B(a)P-induced lung cancer in Swiss albino mice and A549 lung cancer cells.

Autophagy and Its Relationship to Epithelial to Mesenchymal Transition: When Autophagy Inhibition for Cancer Therapy Turns Counterproductive

The manipulation of autophagy for cancer therapy has gained recent interest in clinical settings. Although inhibition of autophagy is currently being used in clinical trials for the treatment of several malignancies, autophagy has been shown to have diverse implications for normal cell homeostasis, cancer cell survival, and signaling to cells in the tumor microenvironment. Among these implications and of relevance for cancer therapy, the autophagic process is known to be involved in the regulation of protein secretion, in tumor cell immunogenicity, and in the regulation of epithelial-to-mesenchymal transition (EMT), a critical step in the process of cancer cell invasion. In this work, we have reviewed recent evidence linking autophagy to the regulation of EMT in cancer and normal epithelial cells, and have discussed important implications for the manipulation of autophagy during cancer therapy.

Dynamically decreased miR-671-5p expression is associated with oncogenic transformation and radiochemoresistance in breast cancer

BACKGROUND

Understanding the molecular alterations associated with breast cancer (BC) progression may lead to more effective strategies for both prevention and management. The current model of BC progression suggests a linear, multistep process from normal epithelial to atypical ductal hyperplasia (ADH), to ductal carcinoma in situ (DCIS), and then invasive ductal carcinoma (IDC). Up to 20% ADH and 40% DCIS lesions progress to invasive BC if left untreated. Deciphering the molecular mechanisms during BC progression is therefore crucial to prevent over- or under-treatment. Our previous work demonstrated that miR-671-5p serves as a tumor suppressor by targeting Forkhead box protein M1 (FOXM1)-mediated epithelial-to-mesenchymal transition (EMT) in BC. Here, we aim to explore the role of miR-671-5p in the progression of BC oncogenic transformation and treatment.

METHODS

The 21T series cell lines, which were originally derived from the same patient with metastatic BC, including normal epithelia (H16N2), ADH (21PT), primary DCIS (21NT), and cells derived from pleural effusion of lung metastasis (21MT), and human BC specimens were used. Microdissection, miRNA transfection, dual-luciferase, radio- and chemosensitivity, and host-cell reactivation (HCR) assays were performed.

RESULTS

Expression of miR-671-5p displays a gradual dynamic decrease from ADH, to DCIS, and to IDC. Interestingly, the decreased expression of miR-671-5p detected in ADH coexisted with advanced lesions, such as DCIS and/or IDC (cADH), but not in simple ADH (sADH). Ectopic transfection of miR-671-5p significantly inhibited cell proliferation in 21NT (DCIS) and 21MT (IDC), but not in H16N2 (normal) and 21PT (ADH) cell lines. At the same time, the effect exhibited in time- and dose-dependent manner. Interestingly, miR-671-5p significantly suppressed invasion in 21PT, 21NT, and 21MT cell lines. Furthermore, miR-671-5p suppressed FOXM1-mediated EMT in all 21T cell lines. In addition, miR-671-5p sensitizes these cell lines to UV and chemotherapeutic exposure by reducing the DNA repair capability.

CONCLUSIONS

miR-671-5p displays a dynamic decrease expression during the oncogenic transition of BC by suppressing FOXM1-mediated EMT and DNA repair. Therefore, miR-671-5p may serve as a novel biomarker for early BC detection as well as a therapeutic target for BC management.

Polyphenols: Immunomodulatory and Therapeutic Implication in Colorectal Cancer

Polyphenolic compounds, widely present in fruits, vegetables, and cereals, have potential benefits for human health and are protective agents against the development of chronic/degenerative diseases including cancer. More recently these bioactive molecules have been gaining great interest as anti-inflammatory and immunomodulatory agents, mainly in neoplasia where the pro-inflammatory context might promote carcinogenesis. Colorectal cancer (CRC) is considered a major public healthy issue, a leading cause of cancer mortality and morbidity worldwide. Epidemiological, pre-clinical and clinical investigations have consistently highlighted important relationships between large bowel inflammation, gut microbiota (GM), and colon carcinogenesis. Many experimental studies and clinical evidence suggest that polyphenols have a relevant role in CRC chemoprevention, exhibit cytotoxic capability vs. CRC cells and induce increased sensitization to chemo/radiotherapies. These effects are most likely related to the immunomodulatory properties of polyphenols able to modulate cytokine and chemokine production and activation of immune cells. In this review we summarize recent advancements on immunomodulatory activities of polyphenols and their ability to counteract the inflammatory tumor microenvironment. We focus on potential role of natural polyphenols in increasing the cell sensitivity to colon cancer therapies, highlighting the polyphenol-based combined treatments as innovative immunomodulatory strategies to inhibit the growth of CRC.

Challenges and Opportunities from Basic Cancer Biology for Nanomedicine for Targeted Drug Delivery

Background:

Effective cancer therapy is still a great challenge for modern medical research due to the complex underlying mechanisms of tumorigenesis and tumor metastasis, and the limitations commonly associated with currently used cancer therapeutic options. Nanotechnology has been implemented in cancer therapeutics with immense potential for improving cancer treatment.

Objective:

Through information about the recent advances regarding cancer hallmarks, we could comprehensively understand the pharmacological effects and explore the mechanisms of the interaction between the nanomaterials, which could provide opportunities to develop mechanism-based nanomedicine to treat human cancers.

Methods:

We collected related information and data from articles.

Results:

In this review, we discussed the characteristics of cancer including tumor angiogenesis, abnormalities in tumor blood vessels, uncontrolled cell proliferation markers, multidrug resistance, tumor metastasis, cancer cell metabolism, and tumor immune system that provide opportunities and challenges for nanomedicine to be directed to specific cancer cells and portray the progress that has been accomplished in application of nanotechnology for cancer treatment.

Conclusion:

The information presented in this review can provide useful references for further studies on developing effective nanomedicine for the treatment of cancer.

Exploring lncRNA-Mediated Regulatory Networks in Endometrial Cancer Cells and the Tumor Microenvironment: Advances and Challenges

Recent studies have revealed both the promise and challenges of targeting long non-coding RNAs (lncRNAs) to diagnose and treat endometrial cancer (EC). LncRNAs are upregulated or downregulated in ECs compared to normal tissues and their dysregulation has been linked to tumor grade, FIGO stage, the depth of myometrial invasion, lymph node metastasis and patient survival. Tumor suppressive lncRNAs (GAS5, MEG3, FER1L4 and LINC00672) and oncogenic lncRNAs (CCAT2, BANCR, NEAT1, MALAT1, H19 and Linc-RoR) have been identified as upstream modulators or downstream effectors of major signaling pathways influencing EC metastasis, including the PTEN/PI3K/AKT/mTOR, RAS/RAF/MEK/ERK, WNT/β-catenin and p53 signaling pathways. TUG1 and TDRG1 stimulate the VEGF-A pathway. PCGEM1 is implicated in activating the JAK/STAT3 pathway. Here, we present an overview of the expression pattern, prognostic value, biological function of lncRNAs in EC cells and their roles within the tumor microenvironment, focusing on the influence of lncRNAs on established EC-relevant pathways. We also describe the emerging classification of EC subtypes based on their lncRNA signature and discuss the clinical implications of lncRNAs as valuable biomarkers for EC diagnosis and potential targets for EC treatment.

Dietary phytochemicals in the regulation of epithelial to mesenchymal transition and associated enzymes: A promising anticancer therapeutic approach

Epithelial to mesenchymal transition (EMT) is a biological phenomenon that plays a primordial role for initiation of metastasis. It renders cancer cells with increased self-renewal and tumor-initiating capabilities and exacerbated resistance to apoptosis and chemotherapy. Hence, regulation of EMT stands out to be an important strategy in controlling the behavior of malignant cells. Despite the enormous amount of preclinical data on the implication of EMT in cancer progression, there is still lack of routine clinical translation at therapeutic levels. The need of EMT-modulating drugs with high efficacy and low cytotoxicity has led to studies involving the evaluation of the efficacy of a plethora of various classes of phytochemicals present in dietary sources of fruits and vegetables. This review summarizes the role of these different classes of phytochemicals, their natural/synthetic analogs, and their nano-formulations in regulation of EMT in various preclinical models through attenuation of primary signaling pathways. Numerous proteins, transcription factors and enzymes targeted by various classes of phytochemicals in repression of EMT has been presented in this review. Additionally, we have critically analyzed the existing literature and provided views on new direction for accelerating the discovery of novel drug candidates which could be cautiously administered without concomitant effects.