Regulation of epithelial-mesenchymal transition and metastasis by TGF-β, P-bodies, and autophagy

Post-transcriptional regulation as a conserved driver of neural crest and cancer-cell migration

Cells have evolved mechanisms to migrate for diverse biological functions. A process frequently deployed during metazoan cell migration is the epithelial-mesenchymal transition (EMT). During EMT, adherent epithelial cells undergo coordinated cellular transitions to mesenchymalize and reduce their intercellular attachments. This is achieved via tightly regulated changes in gene expression, which modulates cell-cell and cell-matrix adhesion to allow movement. The acquisition of motility and invasive properties following EMT allows some mesenchymal cells to migrate through complex environments to form tissues during embryogenesis; however, these processes may also be leveraged by cancer cells, which often co-opt these endogenous programs to metastasize. Post-transcriptional regulation is now emerging as a major conserved mechanism by which cells modulate EMT and migration, which we discuss here in the context of vertebrate development and cancer.

YAP/TAZ enhances P-body formation to promote tumorigenesis

The role of processing bodies (P-bodies) in tumorigenesis and tumor progression is not well understood. Here, we showed that the oncogenes YAP/TAZ promote P-body formation in a series of cancer cell lines. Mechanistically, both transcriptional activation of the P-body-related genes SAMD4A, AJUBA, and WTIP and transcriptional suppression of the tumor suppressor gene PNRC1 are involved in enhancing the effects of YAP/TAZ on P-body formation in colorectal cancer (CRC) cells. By reexpression of PNRC1 or knockdown of P-body core genes (DDX6, DCP1A, and LSM14A), we determined that disruption of P-bodies attenuates cell proliferation, cell migration, and tumor growth induced by overexpression of YAP5SA in CRC. Analysis of a pancancer CRISPR screen database (DepMap) revealed co-dependencies between YAP/TEAD and the P-body core genes and correlations between the mRNA levels of SAMD4A, AJUBA, WTIP, PNRC1, and YAP target genes. Our study suggests that the P-body is a new downstream effector of YAP/TAZ, which implies that reexpression of PNRC1 or disruption of P-bodies is a potential therapeutic strategy for tumors with active YAP.

Energy stress promotes P-bodies formation via lysine-63-linked polyubiquitination of HAX1

Energy stress, characterized by the reduction of intracellular ATP, has been implicated in various diseases, including cancer. Here, we show that energy stress promotes the formation of P-bodies in a ubiquitin-dependent manner. Upon ATP depletion, the E3 ubiquitin ligase TRIM23 catalyzes lysine-63 (K63)-linked polyubiquitination of HCLS1-associated protein X-1 (HAX1). HAX1 ubiquitination triggers its liquid‒liquid phase separation (LLPS) and contributes to P-bodies assembly induced by energy stress. Ubiquitinated HAX1 also interacts with the essential P-body proteins, DDX6 and LSM14A, promoting their condensation. Moreover, we find that this TRIM23/HAX1 pathway is critical for the inhibition of global protein synthesis under energy stress conditions. Furthermore, high HAX1 ubiquitination, and increased cytoplasmic localization of TRIM23 along with elevated HAX1 levels, promotes colorectal cancer (CRC)-cell proliferation and correlates with poor prognosis in CRC patients. Our data not only elucidate a ubiquitination-dependent LLPS mechanism in RNP granules induced by energy stress but also propose a promising target for CRC therapy.

Pooled CRISPR Screening Identifies P-Bodies as Repressors of Cancer Epithelial-Mesenchymal Transition

Epithelial-mesenchymal transition (EMT) is a fundamental cellular process frequently hijacked by cancer cells to promote tumor progression, especially metastasis. EMT is orchestrated by a complex molecular network acting at different layers of gene regulation. In addition to transcriptional regulation, posttranscriptional mechanisms may also play a role in EMT. Here, we performed a pooled CRISPR screen analyzing the influence of 1,547 RNA-binding proteins on cell motility in colon cancer cells and identified multiple core components of P-bodies (PB) as negative modulators of cancer cell migration. Further experiments demonstrated that PB depletion by silencing DDX6 or EDC4 could activate hallmarks of EMT thereby enhancing cell migration in vitro as well as metastasis formation in vivo. Integrative multiomics analysis revealed that PBs could repress the translation of the EMT driver gene HMGA2, which contributed to PB-meditated regulation of EMT. This mechanism is conserved in other cancer types. Furthermore, endoplasmic reticulum stress was an intrinsic signal that induced PB disassembly and translational derepression of HMGA2. Taken together, this study has identified a function of PBs in the regulation of EMT in cancer.

SIGNIFICANCE

Systematic investigation of the influence of posttranscriptional regulation on cancer cell motility established a connection between P-body-mediated translational control and EMT, which could be therapeutically exploited to attenuate metastasis formation.

"Beyond transcription: How post-transcriptional mechanisms drive neural crest EMT"

The neural crest is a stem cell population that originates from the ectoderm during the initial steps of nervous system development. Neural crest cells delaminate from the neuroepithelium by undergoing a spatiotemporally regulated epithelial-mesenchymal transition (EMT) that proceeds in a coordinated wave head-to-tail to exit from the neural tube. While much is known about the transcriptional programs and membrane changes that promote EMT, there are additional levels of gene expression control that neural crest cells exert at the level of RNA to control EMT and migration. Yet, the role of post-transcriptional regulation, and how it drives and contributes to neural crest EMT, is not well understood. In this mini-review, we explore recent advances in our understanding of the role of post-transcriptional regulation during neural crest EMT.

Cancer-associated mesenchymal stem/stromal cells: role in progression and potential targets for therapeutic approaches

Malignancies contain a relatively small number of Mesenchymal stem/stromal cells (MSCs), constituting a crucial tumor microenvironment (TME) component. These cells comprise approximately 0.01-5% of the total TME cell population. MSC differentiation potential and their interaction with the tumor environment enable these cells to affect tumor cells' growth, immune evasion, metastasis, drug resistance, and angiogenesis. This type of MSC, known as cancer-associated mesenchymal stem/stromal cells (CA-MSCs (interacts with tumor/non-tumor cells in the TME and affects their function by producing cytokines, chemokines, and various growth factors to facilitate tumor cell migration, survival, proliferation, and tumor progression. Considering that the effect of different cells on each other in the TME is a multi-faceted relationship, it is essential to discover the role of these relationships for targeting in tumor therapy. Due to the immunomodulatory role and the tissue repair characteristic of MSCs, these cells can help tumor growth from different aspects. CA-MSCs indirectly suppress antitumor immune response through several mechanisms, including decreasing dendritic cells (DCs) antigen presentation potential, disrupting natural killer (NK) cell differentiation, inducing immunoinhibitory subsets like tumor-associated macrophages (TAMs) and Treg cells, and immune checkpoint expression to reduce effector T cell antitumor responses. Therefore, if these cells can be targeted for treatment so that their population decreases, we can hope for the treatment and improvement of the tumor conditions. Also, various studies show that CA-MSCs in the TME can affect other vital aspects of a tumor, including cell proliferation, drug resistance, angiogenesis, and tumor cell invasion and metastasis. In this review article, we will discuss in detail some of the mechanisms by which CA-MSCs suppress the innate and adaptive immune systems and other mechanisms related to tumor progression.

Relating the Biogenesis and Function of P Bodies in Drosophila to Human Disease

Drosophila has been a premier model organism for over a century and many discoveries in flies have furthered our understanding of human disease. Flies have been successfully applied to many aspects of health-based research spanning from behavioural addiction, to dysplasia, to RNA dysregulation and protein misfolding. Recently, Drosophila tissues have been used to study biomolecular condensates and their role in multicellular systems. Identified in a wide range of plant and animal species, biomolecular condensates are dynamic, non-membrane-bound sub-compartments that have been observed and characterised in the cytoplasm and nuclei of many cell types. Condensate biology has exciting research prospects because of their diverse roles within cells, links to disease, and potential for therapeutics. In this review, we will discuss processing bodies (P bodies), a conserved biomolecular condensate, with a particular interest in how Drosophila can be applied to advance our understanding of condensate biogenesis and their role in disease.

Recent Advances in the Role of Autophagy in Endocrine-Dependent Tumors

Autophagy plays a complex role in several cancer types, including endocrine-dependent cancers, by fueling cellular metabolism and clearing damaged substrates. This conserved recycling process has a dual function across tumor types where it can be tumor suppressive at early stages but tumor promotional in established disease. This review highlights the controversial roles of autophagy in endocrine-dependent tumors regarding cancer initiation, tumorigenesis, metastasis, and treatment response. We summarize clinical trial results thus far and highlight the need for additional mechanistic, preclinical, and clinical studies in endocrine-dependent tumors, particularly in breast cancer and prostate cancer.

KRAS and NRAS Translation Is Increased upon MEK Inhibitors-Induced Processing Bodies Dissolution

Overactivation of the mitogen-activated protein kinase (MAPK) pathway is a critical driver of many human cancers. However, therapies directly targeting this pathway lead to cancer drug resistance. Resistance has been linked to compensatory RAS overexpression, but the mechanisms underlying this response remain unclear. Here, we find that MEK inhibitors (MEKi) are associated with an increased translation of the KRAS and NRAS oncogenes through a mechanism involving dissolution of processing body (P-body) biocondensates. This effect is seen across different cell types and is extremely dynamic since removal of MEKi and ERK reactivation result in reappearance of P-bodies and reduced RAS-dependent signaling. Moreover, we find that P-body scaffold protein levels negatively impact RAS expression. Overall, we describe a new feedback loop mechanism involving biocondensates such as P-bodies in the translational regulation of RAS proteins and MAPK signaling.

An update on post-transcriptional regulation of retrotransposons

Retrotransposons, including LINE-1, Alu, SVA, and endogenous retroviruses, are one of the major constituents of human genomic repetitive sequences. Through the process of retrotransposition, some of them occasionally insert into new genomic locations by a copy-paste mechanism involving RNA intermediates. Irrespective of de novo genomic insertions, retrotransposon expression can lead to DNA double-strand breaks and stimulate cellular innate immunity through endogenous patterns. As a result, retrotransposons are tightly regulated by multi-layered regulatory processes to prevent the dangerous effects of their expression. In recent years, significant progress was made in revealing how retrotransposon biology intertwines with general post-transcriptional RNA metabolism. Here, I summarize current knowledge on the involvement of post-transcriptional factors in the biology of retrotransposons, focusing on LINE-1. I emphasize general RNA metabolisms such as methylation of adenine (m⁶ A), RNA 3'-end polyadenylation and uridylation, RNA decay and translation regulation. I discuss the effects of retrotransposon RNP sequestration in cytoplasmic bodies and autophagy. Finally, I summarize how innate immunity restricts retrotransposons and how retrotransposons make use of cellular enzymes, including the DNA repair machinery, to complete their replication cycles.

Kaposi's sarcoma-associated herpesvirus (KSHV) utilizes the NDP52/CALCOCO2 selective autophagy receptor to disassemble processing bodies

Kaposi's sarcoma-associated herpesvirus (KSHV) causes the inflammatory and angiogenic endothelial cell neoplasm, Kaposi's sarcoma (KS). We previously demonstrated that the KSHV Kaposin B (KapB) protein promotes inflammation via the disassembly of cytoplasmic ribonucleoprotein granules called processing bodies (PBs). PBs modify gene expression by silencing or degrading labile messenger RNAs (mRNAs), including many transcripts that encode inflammatory or angiogenic proteins associated with KS disease. Although our work implicated PB disassembly as one of the causes of inflammation during KSHV infection, the precise mechanism used by KapB to elicit PB disassembly was unclear. Here we reveal a new connection between the degradative process of autophagy and PB disassembly. We show that both latent KSHV infection and KapB expression enhanced autophagic flux via phosphorylation of the autophagy regulatory protein, Beclin. KapB was necessary for this effect, as infection with a recombinant virus that does not express the KapB protein did not induce Beclin phosphorylation or autophagic flux. Moreover, we showed that PB disassembly mediated by KSHV or KapB, depended on autophagy genes and the selective autophagy receptor NDP52/CALCOCO2 and that the PB scaffolding protein, Pat1b, co-immunoprecipitated with NDP52. These studies reveal a new role for autophagy and the selective autophagy receptor NDP52 in promoting PB turnover and the concomitant synthesis of inflammatory molecules during KSHV infection.

TG2 as a novel breast cancer prognostic marker promotes cell proliferation and glycolysis by activating the MEK/ERK/LDH pathway

BACKGROUND

Breast cancer (BC) is the most common malignant tumor among women worldwide. Tissue transglutaminase 2 (TG2) has been reported as a major player across several types of cancer. However, the effects of TG2 in breast cancer are less known.

METHODS

The expression of TG2 in patients with BC was detected by immunochemistry staining and RT-qPCR. The correlation of TG2 expression and clinicopathological factors or overall survival (OS) was analyzed by Chi-square test, Kaplan-Meier, and Cox-regression analysis. The effects of TG2 on cell proliferation and glycolysis were investigated in vivo and in vitro by gain- and loss-of-function experiments.

RESULT

Both mRNA and protein levels of TG2 were overexpressed in BC tissues and cultured cells. Clinical stage (p = 0.011), molecular subtype (p<0.001) and survival status (p<0.001) were significantly correlated with TG2 expression. Specifically, TG2 expression was positively associated with the clinical stage (r = 0.193, p = 0.005) and OS (r = 0.230, p = 0.001), while negatively associated with molecular subtype (r = - 0.161, p = 0.020). Overexpressed TG2 was a prognostic factor of poor OS by Cox-regression analysis. Gain- and loss-of-function experiments indicated that cell proliferation and glycolysis were regulated by TG2 via the MEK/ERK/LDH pathway. TG2-induced activation of the MEK/ERK/LDH pathway and glycolysis were attenuated by MEK inhibitor U0126.

CONCLUSION

TG2 is overexpressed in BC, which can serve as an independent prognostic factor for OS. TG2 promotes tumor cell proliferation and increases glycolysis associated with the activation of the MEK/ERK/LHD pathway.

Pseudogenes and Liquid Phase Separation in Epigenetic Expression

Pseudogenes have been considered as non-functional genes. However, peptides and long non-coding RNAs produced by pseudogenes are expressed in different tumors. Moreover, the dysregulation of pseudogenes is associated with cancer, and their expressions are higher in tumors compared to normal tissues. Recent studies show that pseudogenes can influence the liquid phase condensates formation. Liquid phase separation involves regulating different epigenetic stages, including transcription, chromatin organization, 3D DNA structure, splicing, and post-transcription modifications like m⁶A. Several membrane-less organelles, formed through the liquid phase separate, are also involved in the epigenetic regulation, and their defects are associated with cancer development. However, the association between pseudogenes and liquid phase separation remains unrevealed. The current study sought to investigate the relationship between pseudogenes and liquid phase separation in cancer development, as well as their therapeutic implications.

Regulation of Cellular Ribonucleoprotein Granules: From Assembly to Degradation via Post-translational Modification

Cells possess membraneless ribonucleoprotein (RNP) granules, including stress granules, processing bodies, Cajal bodies, or paraspeckles, that play physiological or pathological roles. RNP granules contain RNA and numerous RNA-binding proteins, transiently formed through the liquid–liquid phase separation. The assembly or disassembly of numerous RNP granules is strongly controlled to maintain their homeostasis and perform their cellular functions properly. Normal RNA granules are reversibly assembled, whereas abnormal RNP granules accumulate and associate with various neurodegenerative diseases. This review summarizes current studies on the physiological or pathological roles of post-translational modifications of various cellular RNP granules and discusses the therapeutic methods in curing diseases related to abnormal RNP granules by autophagy.

Condensation properties of stress granules and processing bodies are compromised in Myotonic Dystrophy Type 1

RNA regulation in mammalian cells requires complex physical compartmentalisation, using structures thought to be formed by liquid-liquid phase separation. Disruption of these structures is implicated in numerous degenerative diseases. Myotonic dystrophy type 1 (DM1) is a multi-systemic trinucleotide repeat disorder resulting from an expansion of nucleotides CTG (CTGexp) in the DNA encoding DM1 protein kinase (DMPK). The cellular hallmark of DM1 is the formation of nuclear foci that contain expanded DMPK RNA (CUGexp) (with thymine instead of uracil). We report here the deregulation of stress granules (SGs) and processing bodies (P-bodies), two cytoplasmic structures key for mRNA regulation, in cell culture models of DM1. Alterations to the rates of formation and dispersal of SGs suggest an altered ability of cells to respond to stress associated with DM1, while changes to the structure and dynamics of SGs and P-bodies suggest that a widespread alteration to the biophysical properties of cellular structures is a consequence of the presence of CUGexp RNA.

Summary: Validation of an inducible model of myotonic dystrophy type 1 that shows altered cellular stress responses. These involve phase-separated cellular structures also implicated in other degenerative conditions.

The Bright and the Dark Side of TGF-β Signaling in Hepatocellular Carcinoma: Mechanisms, Dysregulation, and Therapeutic Implications

Simple Summary

Transforming growth factor β (TGF-β) signaling is a preeminent regulator of diverse cellular and physiological processes. Frequent dysregulation of TGF-β signaling has been implicated in cancer. In hepatocellular carcinoma (HCC), the most prevalent form of primary liver cancer, the autocrine and paracrine effects of TGF-β have paradoxical implications. While acting as a potent tumor suppressor pathway in the early stages of malignancy, TGF-β diverts to a promoter of tumor progression in the late stages, reflecting its bright and dark natures, respectively. Within this context, targeting TGF-β represents a promising therapeutic option for HCC treatment. We discuss here the molecular properties of TGF-β signaling in HCC, attempting to provide an overview of its effects on tumor cells and the stroma. We also seek to evaluate the dysregulation mechanisms that mediate the functional switch of TGF-β from a tumor suppressor to a pro-tumorigenic signal. Finally, we reconcile its biphasic nature with the therapeutic implications.

Abstract

Hepatocellular carcinoma (HCC) is associated with genetic and nongenetic aberrations that impact multiple genes and pathways, including the frequently dysregulated transforming growth factor β (TGF-β) signaling pathway. The regulatory cytokine TGF-β and its signaling effectors govern a broad spectrum of spatiotemporally regulated molecular and cellular responses, yet paradoxically have dual and opposing roles in HCC progression. In the early stages of tumorigenesis, TGF-β signaling enforces profound tumor-suppressive effects, primarily by inducing cell cycle arrest, cellular senescence, autophagy, and apoptosis. However, as the tumor advances in malignant progression, TGF-β functionally switches to a pro-tumorigenic signal, eliciting aggressive tumor traits, such as epithelial–mesenchymal transition, tumor microenvironment remodeling, and immune evasion of cancer cells. On this account, the inhibition of TGF-β signaling is recognized as a promising therapeutic strategy for advanced HCC. In this review, we evaluate the functions and mechanisms of TGF-β signaling and relate its complex and pleiotropic biology to HCC pathophysiology, attempting to provide a detailed perspective on the molecular determinants underlying its functional diversion. We also address the therapeutic implications of the dichotomous nature of TGF-β signaling and highlight the rationale for targeting this pathway for HCC treatment, alone or in combination with other agents.

Processing body (P-body) and its mediators in cancer

In recent years, processing bodies (P-bodies) formed by liquid-liquid phase separation, have attracted growing scientific attention due to their involvement in numerous cellular activities, including the regulation of mRNAs decay or storage. These cytoplasmic dynamic membraneless granules contain mRNA storage and decay components such as deadenylase and decapping factors. In addition, different mRNA metabolic regulators, including m⁶A readers and gene-mediated miRNA-silencing, are also associated with such P-bodies. Cancerous cells may profit from these mRNA decay shredders by up-regulating the expression level of oncogenes and down-regulating tumor suppressor genes. The main challenges of cancer treatment are drug resistance, metastasis, and cancer relapse likely associated with cancer stem cells, heterogeneity, and plasticity features of different tumors. The mRNA metabolic regulators based on P-bodies play a great role in cancer development and progression. The dysregulation of P-bodies mediators affects mRNA metabolism. However, less is known about the relationship between P-bodies mediators and cancerous behavior. The current review summarizes the recent studies on P-bodies mediators, their contribution to tumor development, and their potential in the clinical setting, particularly highlighting the P-bodies as potential drug-carriers such as exosomes to anticancer in the future.

The role of RNA processing and regulation in metastatic dormancy

Tumor dormancy is a major contributor to the lethality of metastatic disease, especially for cancer patients who develop metastases years-to-decades after initial diagnosis. Indeed, tumor cells can disseminate during early disease stages and persist in new microenvironments at distal sites for months, years, or even decades before initiating metastatic outgrowth. This delay between primary tumor remission and metastatic relapse is known as "dormancy," during which disseminated tumor cells (DTCs) acquire quiescent states in response to intrinsic (i.e., cellular) and extrinsic (i.e., microenvironmental) signals. Maintaining dormancy-associated phenotypes requires DTCs to activate transcriptional, translational, and post-translational mechanisms that engender cellular plasticity. RNA processing is emerging as an essential facet of cellular plasticity, particularly with respect to the initiation, maintenance, and reversal of dormancy-associated phenotypes. Moreover, dysregulated RNA processing, particularly that associated with alternative RNA splicing and expression of noncoding RNAs (ncRNAs), can occur in DTCs to mediate intrinsic and extrinsic metastatic dormancy. Here we review the pathophysiological impact of alternative RNA splicing and ncRNAs in promoting metastatic dormancy and disease recurrence in human cancers.

MicroRNA-196a promotes renal cancer cell migration and invasion by targeting BRAM1 to regulate SMAD and MAPK signaling pathways

Rationale: MicroRNAs (miRNAs) are endogenous ~22nt RNAs that play critical regulatory roles in various biological and pathological processes, including various cancers. Their function in renal cancer has not been fully elucidated. It has been reported that miR-196a can act as oncogenes or as tumor suppressors depending on their target genes. However, the molecular target for miR-196a and the underlying mechanism in miR-196a promoted cell migration and invasion in renal cancer is still not clear.

Methods: The expression, survival and correlation between miR-196a and BRAM1 were investigated using TCGA analysis and validated by RT-PCR and western blot. To visualize the effect of Bram1 on tumor metastasis in vivo, NOD-SCID gamma (NSG) mice were intravenously injected with RCC4 cells (10⁶ cells/mouse) or RCC4 overexpressing Bram1. In addition, cell proliferation assays, migration and invasion assays were performed to examine the role of miR-196a in renal cells in vitro. Furthermore, immunoprecipitation was done to explore the binding targets of Bram1.

Results: TCGA gene expression data from renal clear cell carcinoma patients showed a lower level of Bram1 expression in patients' specimens compared to adjacent normal tissues. Moreover, Kaplan‑Meier survival data clearly show that high expression of Bram1correlates to poor prognosis in renal carcinoma patients. Our mouse metastasis model confirmed that Bram1 overexpression resulted in an inhibition in tumor metastasis. Target-prediction analysis and dual-luciferase reporter assay demonstrated that Bram1 is a direct target of miR-196a in renal cells. Further, our in vitro functional assays revealed that miR-196a promotes renal cell proliferation, migration, and invasion. Rescue of Bram1 expression reversed miR-196a-induced cell migration. MiR-196a promotes renal cancer cell migration by directly targeting Bram1 and inhibits Smad1/5/8 phosphorylation and MAPK pathways through BMPR1A and EGFR.

Conclusions: Our findings thus provide a new mechanism on the oncogenic role of miR-196a and the tumor-suppressive role of Bram1 in renal cancer cells. Dysregulated miR-196a and Bram1 represent potential prognostic biomarkers and may have therapeutic applications in renal cancer.

Viral Manipulation of a Mechanoresponsive Signaling Axis Disassembles Processing Bodies

Processing bodies (PBs) are ribonucleoprotein granules important for cytokine mRNA decay that are targeted for disassembly by many viruses. Kaposi's sarcoma-associated herpesvirus is the etiological agent of the inflammatory endothelial cancer, Kaposi's sarcoma, and a PB-regulating virus. The virus encodes kaposin B (KapB), which induces actin stress fibers (SFs) and cell spindling as well as PB disassembly. We now show that KapB-mediated PB disassembly requires actin rearrangements, RhoA effectors, and the mechanoresponsive transcription activator, YAP. Moreover, ectopic expression of active YAP or exposure of ECs to mechanical forces caused PB disassembly in the absence of KapB. We propose that the viral protein KapB activates a mechanoresponsive signaling axis and links changes in cell shape and cytoskeletal structures to enhanced inflammatory molecule expression using PB disassembly. Our work implies that cytoskeletal changes in other pathologies may similarly impact the inflammatory environment.

Enhancement of gemcitabine efficacy by K73-03 via epigenetically regulation of miR-421/SPINK1 in gemcitabine resistant pancreatic cancer cells

BACKGROUND

Gemcitabine (GCB) is a first-line chemotherapeutic drug for pancreatic cancer (PCa). However, the resistance begins developing within weeks of chemotherapy. SPINK1 overexpression enhances resistance to chemotherapy. In a recent study, our laboratory established that the oleanolic acid (OA) derivative, K73-03, had a strong inhibitory effect on a SPINK1 overexpressed PCa cells.

PURPOSE

In our current study, we studied the enhancement of GCB inhibitory effect by K73-03, a new novel OA derivative, alone or in combination with GCB on the GCB-resistant PCa cells by mitochondrial damage through regulation of the miR-421/SPINK1.

METHODS

We detected the binding between miR-421 and SPINK1-3'-UTR in GCB-resistant PCa cells using Luciferase reporter assays. Cells viability, apoptosis, migration, and mitochondrial damage were investigated.

RESULTS

The results demonstrated that the combination of K73-03 and GCB suppressed the growth of AsPC-1 and MIA PaCa-2 cells synergistically, with or without GCB resistance. Mechanistic findings showed that a combination of K73-03 and GCB silences SPINK1 epigenetically by miR-421 up-regulating, which leads to mitochondrial damage and inducing apoptosis in GCB-resistant PCa cells.

CONCLUSION

We found an interesting finding that the 73-03 in combination with GCB can improve GCB efficacy and decrease PCa resistance, which induced apoptosis and mitochondrial damage through epigenetic inhibition of SPINK1 transcription by miR-421 up-regulation. This was the first study that used OA derivatives on GCB-resistant PCa cells, so this combined strategy warrants further investigation.

Circulating MiR-1290 as a potential diagnostic and disease monitoring biomarker of human gastrointestinal tumors

Background

Gastrointestinal tumors are a leading cause of mortality worldwide. As shown in our previous study, miR-1290 is overexpressed in colorectal cancer (CRC) and promotes tumor progression. We therefore aimed to explore the potential of circulating miR-1290 as a biomarker for gastrointestinal cancer.

Methods

A serum miRNA sequencing analysis was performed. Then, circulating miRNA detection technologies were established. The expression of miR-1290 was analyzed in gastrointestinal tumor cell lines and culture supernatants. Expression levels of circulating miR-1290 in clinical samples were examined. Associations between miR-1290 expression and clinicopathologic characteristics were analyzed. Xenograft models were generated to assess the fluctuation in serum miR-1290 levels during disease progression.

Results

Through miRNA sequencing, we identified that miR-1290 was overexpressed in serum samples from patients with CRC. We confirmed that human gastrointestinal tumor cells express and secrete miR-1290. The circulating miR-1290 levels was up-regulated in patients with pancreatic cancer (PC) (p < 0.01), CRC (p < 0.05), and gastric cancer (GC) (p < 0.01). High miR-1290 expression levels were associated with tumor size, lymphatic invasion, vascular invasion, distant metastasis, tumor differentiation and AJCC stage in patients with PC and CRC. The area under the curve (AUC) was 0.8857 in patients with PC, with 60.9% sensitivity and 90.0% specificity. The AUC was 0.7852 in patients with CRC, with 42.0% sensitivity and 90.0% specificity. In patients with GC, the AUC was 0.6576, with 26.0% sensitivity and 90.0% specificity. The in vivo model verified that the circulating miR-1290 level was significantly increased after tumor formation and decreased after drug treatment.

Conclusions

Our findings indicate that circulating miR-1290 is a potential biomarker for gastrointestinal cancer diagnosis and monitoring.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08729-0.

Caffeic acid and its derivatives as potential modulators of oncogenic molecular pathways: New hope in the fight against cancer

As a phenolic acid compound, caffeic acid (CA) can be isolated from different sources such as tea, wine and coffee. Caffeic acid phenethyl ester (CAPE) is naturally occurring derivative of CA isolated from propolis. This medicinal plant is well-known due to its significant therapeutic impact including its effectiveness as hepatoprotective, neuroprotective and anti-diabetic agent. Among them, anti-tumor activity of CA has attracted much attention, and this potential has been confirmed both in vitro and in vivo. CA can induce apoptosis in cancer cells via enhancing ROS levels and impairing mitochondrial function. Molecular pathways such as PI3K/Akt and AMPK with role in cancer progression, are affected by CA and its derivatives in cancer therapy. CA is advantageous in reducing aggressive behavior of tumors via suppressing metastasis by inhibiting epithelial-to-mesenchymal transition mechanism. Noteworthy, CA and CAPE can promote response of cancer cells to chemotherapy, and sensitize them to chemotherapy-mediated cell death. In order to improve capacity of CA and CAPE in cancer suppression, it has been co-administered with other anti-tumor compounds such as gallic acid and p-coumaric acid. Due to its poor bioavailability, nanocarriers have been developed for enhancing its ability in cancer suppression. These issues have been discussed in the present review with a focus on molecular pathways to pave the way for rapid translation of CA for clinical use.

Cancer cell adaptability: turning ribonucleoprotein granules into targets

Stress granules (SGs) and processing bodies (P-bodies) are membraneless cytoplasmic condensates of ribonucleoproteins (RNPs). They both regulate RNA fate under physiological and pathological conditions, and are thereby involved in the regulation and maintenance of cellular integrity. During tumorigenesis, cancer cells use these granules to thrive, to adapt to the harsh conditions of the tumor microenvironment (TME), and to protect themselves from anticancer treatments. This ability to provide multiple outcomes not only makes RNP granules promising targets for cancer therapy but also emphasizes the need for more knowledge about the biology of these granules to achieve clinical use. In this review we focus on the role of RNP granules in cancer, and on how their composition and regulation might be used to elaborate therapeutic strategies.

miR-934 promotes breast cancer metastasis by regulation of PTEN and epithelial-mesenchymal transition

Breast cancer (BC) is the most commonly diagnosed malignancy and the leading cause of cancer-related mortality among females. Over 90 % of the cases of death in BC patients are attributed to tumor cell metastasis. Therefore, it is urgently needed to investigate the molecular mechanisms of BC metastasis. The expression of miRNA in BC was evaluated by qRT-PCR and bioinformatics analysis. Clone formation, EdU assays, and subcutaneous xenograft model were used to test the growth of BC cells. Wound healing, transwell assays, and lung-metastasis model were used to explore the effect of miR-934 knockdown on cell metastasis. The miR-934 targets in BC were identified through bioinformatics analysis and luciferase reporter assays. The expression of protein was tested by western blot. The binding of mRNA and RNA-binding-protein was verified using RIP assays. miR-934 expression was significantly elevated in BC tissues, especially in those with lymph node metastasis and associated with poor patient prognosis. Experiments in vitro and in vivo showed that that upregulated miR-934 was not necessarily required for the growth of BC cells. However, miR-934 knockdown significantly inhibited the migration and invasion abilities of BC cells. Moreover, PTEN as identified as the direct target of miR-934 in BC, and miR-934 could promote BC cell metastasis by regulation of PTEN and epithelial-mesenchymal transition (EMT). Our results suggested that targeting miR-934 may be a practical treatment for BC cell metastasis.

Active autophagy in cancer-associated fibroblasts: Recent advances in understanding the novel mechanism of tumor progression and therapeutic response

Autophagy is primarily a homeostatic and catabolic process that is increasingly being recognized to have a pivotal role in the initiation and maintenance of cancer cells, as well as in the emergence of therapeutic resistance. Moreover, in the tumor microenvironment (TME) autophagy plays a crucial and sometimes dichotomous role in tumor progression. Recent studies show that during the early stages of tumor initiation, autophagy suppresses tumorigenesis. However, in the advanced stage of tumorigenesis, autophagy promotes cancer progression by protecting cancer cells against stressful conditions and therapeutic assault. Specifically, in cancer-associated fibroblasts (CAFs), autophagy promotes tumorigenesis not only by providing nutrients to the cancerous cells but also by inducing epithelial to mesenchymal transition, angiogenesis, stemness, and metastatic dissemination of the cancer cells, whereas in the immune cells, autophagy induces the tumor-localized immune response. In the TME, CAFs play a crucial role in cancer cell metabolism, immunoreaction, and growth. Therefore, targeting autophagy in CAFs by several pharmacological inducers like rapamycin or the inhibitor such as chloroquine has gained importance in preclinical and clinical trials. In the present review, we summarized the basic mechanism of autophagy in CAFs along with its role in driving tumorigenic progression through several emerging as well as classical hallmarks of cancer. We also addressed various autophagy inducers as well as inhibitors of autophagy for more efficient cancer management. Eventually, we prioritized some of the outstanding issues that must be addressed with utmost priority in the future to elucidate the role of autophagy in CAFs on tumor progression and therapeutic intervention.

Cisplatin-induced ototoxicity: Updates on molecular mechanisms and otoprotective strategies

Cisplatin is a highly effective antitumor drug generally used in the treatment of solid malignant tumors. However, cisplatin causes severe side effects such as bone marrow depression, nephrotoxicity, and ototoxicity, thus limiting its clinical application. The incidence of ototoxicity induced by cisplatin ranges from 20% to 70%, and it usually manifests as a progressive, bilateral and irreversible hearing loss. Although the etiology of cisplatin-induced ototoxicity remains unclear, an increasing body of evidence suggests that the ototoxicity of cisplatin is mainly related to the production of reactive oxygen species and activation of apoptotic pathway in cochlear tissues. Many drugs have been well proved to protect cisplatin-induced hearing loss in vitro and in vivo. However, the anti-tumor effect of cisplatin is also weakened by systemic administration of those drugs for hearing protection, especially antioxidants. Therefore, establishing a local administration strategy contributes to the otoprotection without affecting the effect of cisplatin. This review introduces the pathology of ototoxicity caused by cisplatin, and focuses on recent developments in the mechanisms and protective strategies of cisplatin-induced ototoxicity.

Exploring the mechanism of Radix Rhei Et Rhizome intervention in intracerebral hemorrhage based on systematic pharmacology and proteomics strategy

OBJECTIVE

To explore the mechanism of Radix Rhei Et Rhizome (Dahuang, DH) intervention in intracerebral hemorrhage (ICH) based on systematic pharmacology and proteomics strategy.

METHODS

The systematic pharmacological strategies were utilized to find the bioactive compounds of Radix Rhei Et Rhizome, predict its potential targets, and collect ICH's disease genes; then, the Cytoscape 3.7.1 software was applied for network construction and network topology analysis. After that, in-depth analysis of the proteomics data of Radix Rhei Et Rhizome intervention in ICH was performed to complement and validate the results of systematic pharmacological predictions.

RESULTS

A total of three major networks were constructed in the present study: (1) compound-compound target network of Radix Rhei Et Rhizome, (2) DH-ICH PPI network, (3) proteomics proteins' PPI network. These three major networks have been analyzed by network topology, and several small networks derived (such as signaling pathway networks). The enrichment analysis showed that Radix Rhei Et Rhizome can intervene in several biological process (such as inflammation, smooth muscle proliferation, platelet activation, blood pressure regulation, angiogenesis, hypoxia, and inflammatory response of leukocytes), signaling pathway (such as FoxO signaling pathway, complement and coagulation cascades, cGMP-PKG signaling pathway, and Rap1 signaling pathway), and reactome pathway (such as signaling by interleukins, interleukin-4 and interleukin-13 signaling, nuclear receptor transcription pathway, and platelet activation).

CONCLUSION

Radix Rhei Et Rhizome may intervene in ICH-related biological process, signaling pathway, and reactome pathway found in this research so as to achieve the effect of treating ICH related injuries.

Inhibition of the Growth of Breast Cancer-Associated Brain Tumors by the Osteocyte-Derived Conditioned Medium

The brain is a common site of metastasis from advanced breast cancer but few effective treatments are available. We examined a therapeutic option with a conditioned medium (CM), focusing on the role of Lrp5 and β-catenin in Wnt signaling, and IL1ra in osteocytes. Osteocytes presented the innate anti-tumor effect and the overexpression of the above genes strengthened their action. In a mouse model, the injection of their CM inhibited mammary tumors and tumor-driven osteolysis. Importantly, Lrp5- and/or IL1ra-overexpressing osteocytes or the local administration of β-catenin-overexpressing CM markedly inhibited brain tumors. In the transport analysis, tumor-suppressing factors in CM were shown to diffuse through the skull. Mechanistically, the CM with overexpression of the above genes downregulated oncogenic genes such as MMP9, Runx2, TGFβ, and Snail in breast cancer cells. Also, the CM with β-catenin overexpression downregulated CXCL1 and CXCL5 and upregulated tumor suppressors such as LIMA1, DSP, p53, and TRAIL in breast cancer cells. Notably, whole-genome proteomics revealed that histone H4 was enriched in CM and acted as an atypical tumor suppressor. Lrp5-overexpressing MSCs were also shown to act as anti-tumor agents. Collectively, this study demonstrated the therapeutic role of engineered CM in brain tumors and the tumor-suppressing action of extracellular histone H4. The result sheds light on the potential CM-based therapy for breast cancer-associated brain metastases in a minimally invasive manner.

Axl and Mertk Receptors Cooperate to Promote Breast Cancer Progression by Combined Oncogenic Signaling and Evasion of Host Antitumor Immunity

Despite the promising clinical benefit of targeted and immune checkpoint blocking therapeutics, current strategies have limited success in breast cancer, indicating that additional inhibitory pathways are required to complement existing therapeutics. TAM receptors (Tyro-3, Axl, and Mertk) are often correlated with poor prognosis because of their capacities to sustain an immunosuppressive environment. Here, we ablate Axl on tumor cells using CRISPR/Cas9 gene editing, and by targeting Mertk in the tumor microenvironment (TME), we observed distinct functions of TAM as oncogenic kinases, as well as inhibitory immune receptors. Depletion of Axl suppressed cell intrinsic oncogenic properties, decreased tumor growth, reduced the incidence of lung metastasis and increased overall survival of mice when injected into mammary fat pad of syngeneic mice, and demonstrated synergy when combined with anti-PD-1 therapy. Blockade of Mertk function on macrophages decreased efferocytosis, altered the cytokine milieu, and resulted in suppressed macrophage gene expression patterns. Mertk-knockout mice or treatment with anti-Mertk-neutralizing mAb also altered the cellular immune profile, resulting in a more inflamed tumor environment with enhanced T-cell infiltration into tumors and T-cell-mediated cytotoxicity. The antitumor activity from Mertk inhibition was abrogated by depletion of cytotoxic CD8α T cells by using anti-CD8α mAb or by transplantation of tumor cells into B6.CB17-Prkdc SCID mice. Our data indicate that targeting Axl expressed on tumor cells and Mertk in the TME is predicted to have a combinatorial benefit to enhance current immunotherapies and that Axl and Mertk have distinct functional activities that impair host antitumor response. SIGNIFICANCE: This study demonstrates how TAM receptors act both as oncogenic tyrosine kinases and as receptors that mediate immune evasion in cancer progression.

An overview of the potential anticancer properties of cardamonin

Cancer is one of the leading causes of mortality, contributing to 9.6 million deaths globally in 2018 alone. Although several cancer treatments exist, they are often associated with severe side effects and high toxicities, leaving room for significant advancements to be made in the field. In recent years, several phytochemicals from plants and natural bioresources have been extracted and tested against various human malignancies using both in vitro and in vivo preclinical model systems. Cardamonin, a chalcone extracted from the Alpinia species, is an example of a natural therapeutic agent that has anti-cancer and anti-inflammatory effects against human cancer cell lines, including breast, lung, colon, and gastric, in both in vitro culture systems as well as xenograft mouse models. Earlier, cardamonin was used as a natural medicine against stomach related issues, diarrhea, insulin resistance, nephroprotection against cisplatin treatment, vasorelaxant and antinociceptive. The compound is well-known to inhibit proliferation, migration, invasion, and induce apoptosis, through the involvement of Wnt/β-catenin, NF-κB, and PI3K/Akt pathways. The good biosafety and pharmacokinetic profiling of cardamonin satisfy it as an attractive molecule for the development of an anticancer agent. The present review has summarized the chemo-preventive ability of cardamonin as an anticancer agent against numerous human malignancies.

Vascular-targeted micelles as a specific MRI contrast agent for molecular imaging of fibrin clots and cancer cells

Molecular medical imaging is intended to increase the accuracy of diagnosis, particularly in cardiovascular and cancer-related diseases, where early detection could significantly increase the treatment success rate. In this study, we present mixed micelles formed from four building blocks as a magnetic resonance imaging targeted contrast agent for the detection of atheroma and cancer cells. The building blocks are a gadolinium-loaded DOTA ring responsible for contrast enhancement, a fibrin-specific CREKA pentapeptide responsible for targeting, a fluorescent dye and DSPE-PEG₂₀₀₀. The micelles were fully characterized in terms of their size, zeta potential, stability, relaxivity and toxicity. Target binding assays performed on fibrin clots were quantified by fluorescence and image signal intensities and proved the binding power. An additional internalization assay showed that the micelles were also designed to specifically enter into cancer cells. Overall, these multimodal mixed micelles represent a potential formulation for MRI molecular imaging of atheroma and cancer cells.

The pleiotropic role of transcription factor STAT3 in oncogenesis and its targeting through natural products for cancer prevention and therapy

Signal transducer and activator of transcription 3 (STAT3) is one of the crucial transcription factors, responsible for regulating cellular proliferation, cellular differentiation, migration, programmed cell death, inflammatory response, angiogenesis, and immune activation. In this review, we have discussed the classical regulation of STAT3 via diverse growth factors, cytokines, G-protein-coupled receptors, as well as toll-like receptors. We have also highlighted the potential role of noncoding RNAs in regulating STAT3 signaling. However, the deregulation of STAT3 signaling has been found to be associated with the initiation and progression of both solid and hematological malignancies. Additionally, hyperactivation of STAT3 signaling can maintain the cancer stem cell phenotype by modulating the tumor microenvironment, cellular metabolism, and immune responses to favor drug resistance and metastasis. Finally, we have also discussed several plausible ways to target oncogenic STAT3 signaling using various small molecules derived from natural products.

Long non-coding RNAs: Emerging regulators for chemo/immunotherapy resistance in cancer stem cells

Cancer stem cells (CSCs) are a small subpopulation of tumor cells critical for tumor development. Their unique abilities, such as self-renewal, have resulted in tumor resistance to various cancer treatments, including traditional chemotherapy and latest immunotherapy. CSCs-targeting therapy is a promising treatment to overcome the therapeutic resistances to different tumors. However, despite their significance, the regulatory mechanism generating therapy-resistant CSCs is still obscure. Long non-coding RNAs (lncRNAs) are key regulators in various biological processes, including cell proliferation, apoptosis, migration, and invasion. Recent studies have revealed that lncRNAs play an important role in the therapeutic resistance of CSCs. Here we summarize the latest studies on the regulatory role of lncRNAs in sustaining the stemness of CSCs, and discuss the associated mechanisms behind these behavior changes in CSCs-related chemo- and immune-resistance. Future research implications are also discussed, shedding light on the potential CSCs-targeted strategies to break through the resistance of current therapies.

The dichotomous role of TGF-β in controlling liver cancer cell survival and proliferation

Hepatocellular carcinoma (HCC) is the major form of primary liver cancer and one of the most prevalent and life-threatening malignancies globally. One of the hallmarks in HCC is the sustained cell survival and proliferative signals, which are determined by the balance between oncogenes and tumor suppressors. Transforming growth factor beta (TGF-β) is an effective growth inhibitor of epithelial cells including hepatocytes, through induction of cell cycle arrest, apoptosis, cellular senescence, or autophagy. The antitumorigenic effects of TGF-β are bypassed during liver tumorigenesis via multiple mechanisms. Furthermore, along with malignant progression, TGF-β switches to promote cancer cell survival and proliferation. This dichotomous nature of TGF-β is one of the barriers to therapeutic targeting in liver cancer. Thereafter, understanding the underlying molecular mechanisms is a prerequisite for discovering novel antitumor drugs that may specifically disable the growth-promoting branch of TGF-β signaling or restore its tumor-suppressive arm. This review summarizes how TGF-β inhibits or promotes liver cancer cell survival and proliferation, highlighting the functional switch mechanisms during the process.

Mesenchymal stromal cells reprogram monocytes and macrophages with processing bodies

Mesenchymal stromal cells (MSCs) are widely used in clinical trials because of their ability to modulate inflammation. The success of MSCs has been variable over 25 years, most likely due to an incomplete understanding of their mechanism. After MSCs are injected, they traffic to the lungs and other tissues where they are rapidly cleared. Despite being cleared, MSCs suppress the inflammatory response in the long term. Using human cord tissue-derived MSCs (hCT-MSCs), we demonstrated that hCT-MSCs directly interact and reprogram monocytes and macrophages. After engaging hCT-MSCs, monocytes and macrophages engulfed cytoplasmic components of live hCT-MSCs, then downregulated gene programs for antigen presentation and costimulation, and functionally suppressed the activation of helper T cells. We determined that low-density lipoprotein receptor-related proteins on monocytes and macrophages mediated the engulfment of hCT-MSCs. Since a large amount of cellular information can be packaged in cytoplasmic RNA processing bodies (p-bodies), we generated p-body deficient hCT-MSCs and confirmed that they failed to reprogram monocytes and macrophages in vitro and in vivo. hCT-MSCs suppressed an inflammatory response caused by a nasal lipopolysaccharide challenge. Although both control and p-body deficient hCT-MSCs were engulfed by infiltrating lung monocytes and macrophages, p-body deficient hCT-MSCs failed to suppress inflammation and downregulate MHC-II. Overall, we identified a novel mechanism by which hCT-MSCs indirectly suppressed a T-cell response by directly interacting and reprogramming monocytes and macrophages via p-bodies. The results of this study suggest a novel mechanism for how MSCs can reprogram the inflammatory response and have long-term effects to suppress inflammation.

Potential of guggulsterone, a farnesoid X receptor antagonist, in the prevention and treatment of cancer

Cancer is one of the most dreadful diseases in the world with a mortality of 9.6 million annually. Despite the advances in diagnosis and treatment during the last couple of decades, it still remains a serious concern due to the limitations associated with currently available cancer management strategies. Therefore, alternative strategies are highly required to overcome these glitches. The importance of medicinal plants as primary healthcare has been well-known from time immemorial against various human diseases, including cancer. Commiphora wightii that belongs to Burseraceae family is one such plant which has been used to cure various ailments in traditional systems of medicine. This plant has diverse pharmacological properties such as antioxidant, antibacterial, antimutagenic, and antitumor which mostly owes to the presence of its active compound guggulsterone (GS) that exists in the form of Z- and E-isomers. Mounting evidence suggests that this compound has promising anticancer activities and was shown to suppress several cancer signaling pathways such as NF-κB/ERK/MAPK/AKT/STAT and modulate the expression of numerous signaling molecules such as the farnesoid X receptor, cyclin D1, survivin, caspases, HIF-1α, MMP-9, EMT proteins, tumor suppressor proteins, angiogenic proteins, and apoptotic proteins. The current review is an attempt to summarize the biological activities and diverse anticancer activities (both in vitro and in vivo) of the compound GS and its derivatives, along with its associated mechanism against various cancers.

Associations of TIMP-3 Genetic Polymorphisms with EGFR Statuses and Cancer Clinicopathologic Development in Lung Adenocarcinoma Patients

Lung adenocarcinoma (LADC) is a major subtype of lung cancer, particularly among populations of East Asia. The epidermal growth factor receptor (EGFR) is the most frequently mutated oncogene promoting LADC progression and can serve as a therapeutic target in LADC. The tissue inhibitor of metalloproteinases (TIMP)-3 is a major regulator of extracellular matrix turnover via targeting of matrix metalloproteinases (MMPs), and thus, plays a critical role in tumor development and progression. The purpose of this study was to investigate potential associations among TIMP-3 genetic polymorphisms, EGFR statuses, and cancer clinicopathologic development in patients with LADC. In this study, 277 LADC patients with different EGFR statuses were recruited to dissect the allelic discrimination of TIMP-3 -1296 T>C (rs9619311), TIMP3 249T>C (rs9862), and TIMP3 261C>T (rs11547635) polymorphisms using a TaqMan allelic discrimination assay. Our data showed that compared to those LADC patients with wild-type CC homozygotes of TIMP-3 rs9862, patients harboring TT homozygotes of rs9862 were at a higher risk of developing mutant EGFR (adjusted odds ratio (AOR) = 2.530; 95% confidence interval (CI): 1.230–5.205; p = 0.012), particularly the EGFR L858R point mutation (AOR = 2.975; 95% CI: 1.182–7.488; p = 0.021). Moreover, we observed that TIMP-3 TT homozygotes of rs9862 were correlated with the incidence of EGFR mutations in patients with a smoking habit (p = 0.045). Within male patients harboring a mutant EGFR, TIMP-3 rs9862 T (CT+TT) allele carriers were at higher risk of developing an advanced stage (p = 0.025) and lymph node metastasis (p = 0.043). Further analyses of clinical datasets revealed correlations of TIMP-3 expression with a favorable prognosis in patients with LADC. In conclusion, the data suggest that TIMP-3 rs9862 polymorphisms may contribute to identify subgroups of lung cancer patients at high risk for tumor progression, among carriers of LADC-bearing mutant EGFR.

Circular RNA hsa_circ_0000282 contributes to osteosarcoma cell proliferation by regulating miR-192/XIAP axis

Background

Circular RNAs (circRNAs) have emerged as a novel category of non-coding RNA, which exhibit a pivotal effect on regulating gene expression and biological functions, yet how circRNAs function in osteosarcoma (OSA) still demands further investigation. This study aimed at probing into the function of hsa_circ_0000282 in OSA.

Methods

The expressions of circ_0000282 and miR-192 in OSA tissues and cell lines were examined by quantitative real-time polymerase chain reaction (qRT-PCR), and the correlation between the expression level of circ_0000282 and clinicopathological features of OSA patients was analyzed. The expressions of X-linked inhibitor of apoptosis protein (XIAP), B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein (Bax) in OSA cells were assayed by Western blot. The proliferation and apoptosis of OSA cells were examined by CCK-8, BrdU and flow cytometry, respectively. Bioinformatics analysis, dual-luciferase reporter gene assay and RIP experiments were employed to predict and validate the targeting relationships between circ_0000282 and miR-192, and between miR-192 and XIAP, respectively.

Results

Circ_0000282 was highly expressed in OSA tissues and cell lines, which represented positive correlation with Enneking stage of OSA patients and negative correlation with tumor differentiation degree. In vitro experiments confirmed that overexpression of circ_0000282 markedly facilitated OSA cell proliferation and repressed cancer cell apoptosis in comparison to control group. Besides, knockdown of circ_0000282 repressed OSA cell proliferation and promoted apoptosis. Additionally, the binding relationships between circ_0000282 and miR-192, and between miR-192 and XIAP were validated. Circ_0000282 indirectly up-regulated XIAP expression by adsorbing miR-192, thereby playing a role in promoting cancer in OSA.

Conclusion

Circ_0000282 was a novel oncogenic circRNA in OSA. Circ_0000282/miR-192/XIAP axis regulated OSA cell proliferation apoptosis with competitive endogenous RNA mechanism.

MicroRNA-15b in extracellular vesicles from arsenite-treated macrophages promotes the progression of hepatocellular carcinomas by blocking the LATS1-mediated Hippo pathway

Arsenic, a human carcinogen, causes various human cancers, including those of the skin, lung, and liver. Hepatocellular carcinomas (HCCs), which have high mortality, are common malignancies worldwide. Tumor-associated macrophages (TAMs), which are considered to be similar to M2-polarized macrophages, promote tumor invasion and progression. Small non-coding RNAs (miRNAs) regulate expression of genes involved in progression of various malignancies. Extracellular vesicles (EVs), as mediators of cell communication, pass specific miRNAs directly from TAMs to tumor cells, promoting tumor pathogenesis and metastasis. In HCCs, large tumor suppressor kinase 1 (LATS1), functions as a tumor suppressor. However, the molecular mechanism by which miRNA modulates LATS1 expression in HCCs remains unclear. The results show that exposure to arsenite, increased miR-15b levels and induced M2 polarization of THP-1 cells. Elevated levels of miR-15b were transferred from arsenite-treated-THP-1 (As-THP-1) cells to HCC cells via miR-15b in EVs inhibited activation of the Hippo pathway by targeting LATS1, and was involved in promoting the proliferation, migration, and invasion of HCC cells. In conclusion, miR-15b in EVs from As-THP-1 cells is transferred to HCC cells, in which it targets and downregulates LATS1 expression and promotes the proliferation, migration, and invasion of HCC cells.

Progression-Free Survival and Overall Survival of CDK 4/6 Inhibitors Plus Endocrine Therapy in Metastatic Breast Cancer: A Systematic Review and Meta-Analysis

The introduction of CDK4/6 inhibitors in combination with endocrine therapy (ET) represents the most relevant advance in the management of hormone receptor (HR) positive, HER2-negative metastatic breast cancer over the last few years. This meta-analysis of randomized controlled trials (RCTs) is aimed to better characterize the efficacy of CDK4/6 inhibitors in some relevant subgroups and to test heterogeneity between different compounds with a particular focus on their ability to improve overall survival (OS). Pooled estimates of hazard ratios (HRs) were computed for progression-free survival (PFS), OS, and objective response rate (ORR) analysis in predefined subgroups to better understand treatment effect concerning specific patients’ characteristics. To estimate the absolute benefit in terms of PFS, pooled survival curves were generated by pooling the data of all trials. A total of eight RCTs were included. Adding a CDK4/6 inhibitor to ET is beneficial in terms of PFS, irrespective of the presence or not of visceral metastases, the number of metastatic sites, and the length of the treatment-free interval (TFI). The addition of CDK4/6 inhibitors produces a significant OS improvement, both in aromatase inhibitor (AI)-sensitive (HR 0.75, 95% CI) and AI-resistant patients (HR 0.77, 95% CI [0.67–0.89]). Pooled data from each single drug show that palbociclib remains the only class member not showing a statistically significant HR for OS (HR 0.83, 95% CI [0.68–1.02]).

Possible applications of salvianolic acid B against different cancers

Cancer is the second death causing disease worldwide after cardiovascular abnormalities. The difficulty in treating tumor cells with more precise targeted interventions and recurrence of cancer after treatment may pose great difficulty in developing sustainable therapeutic regimens. These limitations have prompted the need to explore several compounds with ability to cease tumor growth while at the same time induce apoptosis of tumor cells. Several studies have emphasized the use of natural compounds as antitumor agents due to their high efficacy against cancer cells and low toxicity in normal cells. Salvianolic acid B (SAB), a naturally occurring phenolic compound extracted from the radix of Chinese herb Salvia miltiorrhiza can induce apoptosis in different types of tumor cells. It can be used to treat cardiovascular and neurodegenerative disorders, hepatic fibrosis, and cancers. Several studies have shown that SAB can mitigate tumorigenesis by modulating MAPK, PI3K/AKT, and NF-ĸB signaling pathways. It also sensitizes the tumor cells to different anti-cancer agents by reversing the multi-drug resistance mechanisms found in tumor cells. This review summarizes the studies showing antitumor potential of SAB in different types of cancer cell lines, animal models and highlights the possible mechanisms through which SAB can induce apoptosis, inhibit growth and metastasis in tumor cells. Moreover, the possible role of nano-technological approaches to induce targeted delivery of SAB to eradicate tumor cells has been also discussed.

Combined LIM kinase 1 and p21-Activated kinase 4 inhibitor treatment exhibits potent preclinical antitumor efficacy in breast cancer

LIM kinase 1 (LIMK1) and p21-activated kinase 4 (PAK4) are often over-expressed in breast tumors, which causes aggressive cancer phenotypes and unfavorable clinical outcomes. In addition to the well-defined role in regulating cell division, proliferation and invasion, the two kinases promote activation of the MAPK pathway and cause endocrine resistance through phosphorylating estrogen receptor alpha (ERα). PAK4 specifically phosphorylates LIMK1 and its functional partners, indicating possible value of suppressing both kinases in cancers that over-express PAK4 and/or LIMK1. Here, for the first time, we assessed the impact of combining LIMK1 inhibitor LIMKi 3 and PAK4 inhibitor PF-3758309 in preclinical breast cancer models. LIMK1 and PAK4 pharmacological inhibition synergistically reduced the survival of various cancer cell lines, exhibiting specific efficacy in luminal and HER2-enriched models, and suppressed development and ERα-driven signals in a BT474 xenograft model. In silico analysis demonstrated the cell lines with reliance on LIMK1 were the most prone to be susceptible to PAK4 inhibition. Double LIMK1 and PAK4 targeting therapy can be a successful therapeutic strategy for breast cancer, with a unique efficiency in the subtypes of luminal and HER2-enriched tumors.

miR-421 up-regulation by the oleanolic acid derivative K73-03 regulates epigenetically SPINK1 transcription in pancreatic cancer cells leading to metabolic changes and enhanced apoptosis

SPINK1 overexpression promotes cancer cell aggressiveness and confers chemo-resistance to multiple drugs in pancreatic cancer. Oleanolic acid (OA) derivatives possess active effects against different cancers. Here we report the effect of K73-03, a new novel OA derivative, against pancreatic cancer through mitochondrial dysfunction via miR-421/SPINK1 regulation. We examined the binding ability of miR-421 with SPINK1-3'UTR Luciferase reporter assays. Moreover, miR-421/SPINK1 expressions in pancreatic cancer, with or without K73-03 treatment, were evaluated. Cells viability, migration, autophagy, mitochondrial function and apoptosis were examined with or without K73-03 treatment. We established that the K73-03 effect on the miR-421 that plays a crucial role in the regulation of SPINK1 in pancreatic cancer. Our findings indicated that K73-03 inhibited the mitochondrial function that led to inducing autophagy and apoptosis through epigenetic SPINK1 down-regulation via miR-421 up-regulation in pancreatic cancer. Furthermore, the inhibition of miR-421 expression in pancreatic cancer cells abolished the efficacy of K73-03 against SPINK1 oncogenic properties. We found an interesting finding that the interaction between miR-421 and SPINK1 is related to mitochondrial function through the effect of K73-03. Further, SPINK1 appear to be the molecular targets of K73-03 especially more than gemcitabine.

Comparative Analysis of Blood and Bone Marrow for the Detection of Circulating and Disseminated Tumor Cells and Their Prognostic and Predictive Value in Esophageal Cancer Patients

Hematogenic tumor cell spread is a key event in metastasis. However, the clinical significance of circulating tumor cells (CTC) in the blood and disseminated tumor cells (DTC) in bone marrow is still not fully understood. Here, the presence of DTC and CTC in esophageal cancer (EC) patients and its correlation with clinical parameters was investigated to evaluate the CTC/DTC prognostic value in EC. This study included 77 EC patients with complete surgical tumor resection. CTC and DTC were analyzed in blood and bone marrow using nested CK20 reverse transcription-nested polymerase chain reaction (RT-PCR) and findings were correlated with clinical data. Twenty-seven of 76 patients (36.5%) showed CK20 positivity in the blood, 19 of 61 patients (31.1%) in bone marrow, and 40 (51.9%) of 77 patients were positive in either blood or bone marrow or both. In multivariate analyses, only the DTC status emerged as independent predictor of overall and tumor specific survival. Our study revealed that, while the presence of CTC in blood is not associated with a worse prognosis, DTC detection in the bone marrow is a highly specific and independent prognostic marker in EC patients. Larger cohort studies could unravel how this finding can be translated into improved therapy management in EC.

Multidirectional Strategies for Targeted Delivery of Oncolytic Viruses by Tumor Infiltrating Immune Cells

Oncolytic virus (OV) immunotherapy has demonstrated to be a promising approach in cancer treatment due to tumor-specific oncolysis. However, their clinical use so far has been largely limited due to the lack of suitable delivery strategies with high efficacy. Direct 'intratumoral' injection is the way to cross the hurdles of systemic toxicity, while providing local effects. Progress in this field has enabled the development of alternative way using 'systemic' oncolytic virotherapy for producing better results. One major potential roadblock to systemic OV delivery is the low virus persistence in the face of hostile immune system. The delivery challenge is even greater when attempting to target the oncolytic viruses into the entire tumor mass, where not all tumor cells are equally exposed to exactly the same microenvironment. The microenvironment of many tumors is known to be massively infiltrated with various types of leucocytes in both primary and metastatic sites. Interestingly, this intratumoral immune cell heterogeneity exhibits a degree of organized distribution inside the tumor bed as evidenced, for example, by the hypoxic tumor microenviroment where predominantly recruits tumor-associated macrophages. Although in vivo OV delivery seems complicated and challenging, recent results are encouraging for decreasing the limitations of systemically administered oncolytic viruses and an improved efficiency of oncolytic viral therapy in targeting cancerous tissues in vitro. Here, we review the latest developments of carrier cell-based oncolytic virus delivery using tumor-infiltrating immune cells with a focus on the main features of each cellular vehicle.

Cancer and SOX proteins: New insight into their role in ovarian cancer progression/inhibition

Transcription factors are potential targets in disease therapy, particularly in cancer. This is due to the fact that transcription factors regulate a variety of cellular events, and their modulation has opened a new window in cancer therapy. Sex-determining region Y (SRY)-related high-mobility group (HMG) box (SOX) proteins are potential transcription factors that are involved in developmental processes such as embryogenesis. It has been reported that abnormal expression of SOX proteins is associated with development of different cancers, particularly ovarian cancer (OC). In the present review, our aim is to provide a mechanistic review of involvement of SOX members in OC. SOX members may suppress and/or promote aggressiveness and proliferation of OC cells. Clinical studies have also confirmed the potential of transcription factors as diagnostic and prognostic factors in OC. Notably, studies have demonstrated the relationship between SOX members and other molecular pathways such as ST6Ga1-I, PI3K, ERK and so on, leading to more complexity. Furthermore, SOX members can be affected by upstream mediators such as microRNAs, long non-coding RNAs, and so on. It is worth mentioning that the expression of each member of SOX proteins is corelated with different stages of OC. Furthermore, their expression determines the response of OC cells to chemotherapy. These topics are discussed in this review to shed some light on role of SOX transcription factors in OC.

Targeting gut barrier dysfunction with phytotherapies: Effective strategy against chronic diseases

The intestinal epithelial layer serves as a physical and functional barrier between the microbe-rich lumen and immunologically active submucosa; it prevents systemic translocation of microbial pyrogenic products (e.g. endotoxin) that elicits immune activation upon translocation to the systemic circulation. Loss of barrier function has been associated with chronic 'low-grade' systemic inflammation which underlies pathogenesis of numerous no-communicable chronic inflammatory disease. Thus, targeting gut barrier dysfunction is an effective strategy for the prevention and/or treatment of chronic disease. This review intends to emphasize on the beneficial effects of herbal formulations, phytochemicals and traditional phytomedicines in attenuating intestinal barrier dysfunction. It also aims to provide a comprehensive understanding of intestinal-level events leading to a 'leaky-gut' and systemic complications mediated by endotoxemia. Additionally, a variety of detectable markers and diagnostic criteria utilized to evaluate barrier improving capacities of experimental therapeutics has been discussed. Collectively, this review provides rationale for targeting gut barrier dysfunction by phytotherapies for treating chronic diseases that are associated with endotoxemia-induced systemic inflammation.