Tumor microenvironment complexity: emerging roles in cancer therapy

Aptamer-conjugated nano-liposome for immunogenic chemotherapy with reversal of immunosuppression

Cancer cells have various immune evasion mechanisms that resist the immune cells by reprogramming the tumor microenvironment (TME), such as programmed death-ligand 1 (PD-L1) and indoleamine 2,3-dioxygenase-1 (IDO1) overexpression. One of the approaches to restore antitumor immune response by T-cells is through induction of immunogenic cell death (ICD). Thus, drug carrier containing IDO1 siRNA and ICD inducer would be effective anticancer regimen to modulate the immunosuppressive TME by reversing the IDO1-mediated immunosuppression in a synergistic combination with ICD induction. However, numerous nanocarrier platforms for co-delivery of multiple drugs mostly depend on the enhanced permeation and retention (EPR), which is insufficient to achieve selectivity in tumor sites harboring various types of cells. We designed a targeted drug delivery system using nano-sized liposomes functionalized with anti-CD44 and anti-PD-L1 DNA aptamers, which target breast cancer cells and inhibit PD-1/PD-L1 interaction between cancer cells and T-cells. To reverse immunosuppressive TME and reactivate immune response, cancer-targeting nano-liposomes were prepared to contain immunogenic cell death inducer (Doxorubicin, DOX) and IDO1 siRNA, namely Aptm[DOX/IDO1]. The Aptm[DOX/IDO1] specifically delivered the loaded DOX and IDO1 siRNA into target breast cancer cells through aptamer-mediated endocytosis. Cancer-targeted DOX/IDO1 siRNA delivery enhanced ICD and suppressed IDO1 expression with significantly high toxicity in cancer cells. We demonstrated that Aptm[DOX/IDO1] could achieve synergistic antitumor effects by facilitating ICD response and simultaneous reversal of the immunosuppressive TME with IDO1 knockdown in the subcutaneous breast cancer model mice, thus reducing tumor size. These antitumor effects were exerted with intratumoral infiltration of CD8⁺ cytotoxic T lymphocyte as well as attenuation of regulatory T-cell recruitment in the tumor sites. We further proved that our Aptm[DOX/IDO1] strategy significantly reduced tumor metastasis in tumor-xenograft mice through a synergistic combination of cancer cell-targeted ICD induction and reversal of the IDO1-mediated immunosuppressive TME. Our nanocarrier platform based on cationic liposomes containing DOX and IDO1 siRNA, which are conjugated with two DNA aptamers targeting the cancer cell surface, accomplished synergistic chemoimmunotherapy through tumor-specific immune modulation into immune-favorable TME in vivo.

Utility and Drawbacks of Chimeric Antigen Receptor T Cell (CAR-T) Therapy in Lung Cancer

The present treatments for lung cancer include surgical resection, radiation, chemotherapy, targeted therapy, and immunotherapy. Despite advances in therapies, the prognosis of lung cancer has not been substantially improved in recent years. Chimeric antigen receptor (CAR)-T cell immunotherapy has attracted growing interest in the treatment of various malignancies. Despite CAR-T cell therapy emerging as a novel potential therapeutic option with promising results in refractory and relapsed leukemia, many challenges limit its therapeutic efficacy in solid tumors including lung cancer. In this landscape, studies have identified several obstacles to the effective use of CAR-T cell therapy including antigen heterogeneity, the immunosuppressive tumor microenvironment, and tumor penetration by CAR-T cells. Here, we review CAR-T cell design; present the results of CAR-T cell therapies in preclinical and clinical studies in lung cancer; describe existing challenges and toxicities; and discuss strategies to improve therapeutic efficacy of CAR-T cells.

Facile Synthesis of Fe3O4@Au/PPy-DOX Nanoplatform with Enhanced Glutathione Depletion and Controllable Drug Delivery for Enhanced Cancer Therapeutic Efficacy

The complex physiological environment and inherent self-healing function of tumors make it difficult to eliminate malignant tumors by single therapy. In order to enhance the efficacy of antitumor therapy, it is significant and challenging to realize multi-mode combination therapy by utilizing/improving the adverse factors of the tumor microenvironment (TME). In this study, a novel Fe₃O₄@Au/PPy nanoplatform loaded with a chemotherapy drug (DOX) and responsive to TME, near-infrared (NIR) laser and magnetic field was designed for the combination enhancement of eliminating the tumor. The Fe²⁺ released at the low pH in TME can react with endogenous H₂O₂ to induce toxic hydroxyl radicals (·OH) for chemodynamic therapy (CDT). At the same time, the generated Fe³⁺ could deplete overexpressed glutathione (GSH) at the tumor site to prevent reactive oxygen species (ROS) from being restored while producing Fe²⁺ for CDT. The designed Fe₃O₄@Au/PPy nanoplatform had high photothermal (PT) conversion efficiency and photodynamic therapy (PDT) performance under NIR light excitation, which can promote CDT efficiency and produce more toxic ROS. To maximize the cancer-killing efficiency, the nanoplatform can be successfully loaded with the chemotherapeutic drug DOX, which can be efficiently released under NIR excitation and induction of slight acidity at the tumor site. In addition, the nanoplatform also possessed high saturation magnetization (20 emu/g), indicating a potential magnetic targeting function. In vivo and in vitro results identified that the Fe₃O₄@Au/PPy-DOX nanoplatform had good biocompatibility and magnetic-targeted synergetic CDT/PDT/PTT/chemotherapy antitumor effects, which were much better than those of the corresponding mono/bi/tri-therapies. This work provides a new approach for designing intelligent TME-mediated nanoplatforms for synergistically enhancing tumor therapy.

A targeted nanomodulator capable of manipulating tumor microenvironment against metastasis

Recently, lactate has been considered as an alternative direct energy substance to glucose for tumor proliferation and metastasis. Meanwhile, mitochondria, as important energy-supplying organelles, are also closely related to tumor progression. Consequently, a new research direction for lactate comprises lactate deprivation coupled with mitochondria-targeted phototherapy to achieve a safer and more effective strategy against tumor metastasis. Herein, linoleic acid-conjugated hyaluronic acid (HL), disulfide bond-rich nanovehicle (mesoporous silica, MOS), mitochondria-targeted IR780 (M780) and lactate oxidase (LOD) are rationally designed as a specific-targeting metabolism nanomodulator (HL/MOS@M780&LOD NPs), fulfilling the task of simultaneous depriving cells of lactate and damaging mitochondria to prevent tumor metastasis. Interestingly, M780-mediated photodynamic therapy (PDT) and LOD-mediated starvation therapy can effectively exacerbate the hypoxia state of tumor cells, thereby increasing the free iron levels to activate ferroptosis. On one hand, pyruvic acid and H₂O₂ generated by LOD-mediated lactate metabolism can provide powerful conditions for iron-catalyzed ferroptosis. On the other, the depleted GSH and increased reactive oxygen species (ROS) can oxidize linoleic acid into lipid peroxides (LPO) to further augment ferroptosis. The designed nanomodulator therefore shows great promise for fighting tumor metastasis by manipulating energy metabolism and the hypoxia microenvironment.

FAM198B promotes colorectal cancer progression by regulating the polarization of tumor-associated macrophages via the SMAD2 signaling pathway

Colorectal cancer (CRC) is one of the most common malignant tumors. Tumor-associated macrophages (TAMs) promote the progression of CRC, but the mechanism is not completely clear. The present study aimed to reveal the expression and function of FAM198B in TAMs, and the role of FAM198B in mediating macrophage polarization in CRC. The role of FAM198B in macrophage activity, cell cycle, and angiogenesis was evaluated by CCK-8 assay, flow cytometry, and vasculogenic mimicry assay. The effects of FAM198B on macrophage polarization were determined by flow cytometry. The function of FAM198B-mediated macrophage polarization on CRC progression was evaluated by transwell assays. Bioinformatic analyses and rescue assays were performed to identify biological functions and signaling pathways involved in FAM198B regulation of macrophage polarization. Increased FAM198B expression in TAMs is negatively associated with poor CRC prognosis. Functional assays showed that FAM198B promotes M2 macrophage polarization, which leads to CRC cell proliferation, migration, and invasion. Mechanistically, FAM198B regulates the M2 polarization of macrophages by targeting SMAD2, identifying the SMAD2 pathway as a mechanism by which FAM198B promotes CRC progression through regulating macrophage polarization. These findings provide a possible molecular mechanism for FAM198B in TAMs in CRC and suggest that FAM198B may be a novel therapeutic target in CRC.

Epigenetic Underpinnings of Inflammation: A Key to Unlock the Tumor Microenvironment in Glioblastoma

Glioblastoma (GBM) is the most common malignant brain tumor in adults, and immunotherapies and genetic therapies for GBM have evolved dramatically over the past decade, but GBM therapy is still facing a dilemma due to the high recurrence rate. The inflammatory microenvironment is a general signature of tumors that accelerates epigenetic changes in GBM and helps tumors avoid immunological surveillance. GBM tumor cells and glioma-associated microglia/macrophages are the primary contributors to the inflammatory condition, meanwhile the modification of epigenetic events including DNA methylation, non-coding RNAs, and histone methylation and deacetylases involved in this pathological process of GBM, finally result in exacerbating the proliferation, invasion, and migration of GBM. On the other hand, histone deacetylase inhibitors, DNA methyltransferases inhibitors, and RNA interference could reverse the inflammatory landscapes and inhibit GBM growth and invasion. Here, we systematically review the inflammatory-associated epigenetic changes and regulations in the microenvironment of GBM, aiming to provide a comprehensive epigenetic profile underlying the recognition of inflammation in GBM.

Acquired αSMA Expression in Pericytes Coincides with Aberrant Vascular Structure and Function in Pancreatic Ductal Adenocarcinoma

The subpopulations of tumor pericytes undergo pathological phenotype switching, affecting their normal function in upholding structural stability and cross-communication with other cells. In the case of pancreatic ductal adenocarcinoma (PDAC), a significant portion of blood vessels are covered by an α-smooth muscle actin (αSMA)-expressing pericyte, which is normally absent from capillary pericytes. The Desmin^lowαSMA^high phenotype was significantly correlated with intratumoral hypoxia and vascular leakiness. Using an in vitro co-culture system, we demonstrated that cancer cell-derived exosomes could induce ectopic αSMA expression in pericytes. Exosome-treated αSMA⁺ pericytes presented altered pericyte markers and an acquired immune-modulatory feature. αSMA⁺ pericytes were also linked to morphological and biomechanical changes in the pericyte. The PDAC exosome was sufficient to induce αSMA expression by normal pericytes of the healthy pancreas in vivo, and the vessels with αSMA⁺ pericytes were leaky. This study demonstrated that tumor pericyte heterogeneity could be dictated by cancer cells, and a subpopulation of these pericytes confers a pathological feature.

Antibody-drug conjugates: beyond current approvals and potential future strategies

The recent approvals for antibody-drug conjugates (ADCs) in multiple malignancies in recent years have fuelled the ongoing development of this class of drugs. These novel agents combine the benefits of high specific targeting of oncogenic cell surface antigens with the additional cell kill from high potency cytotoxic payloads, thus achieving wider therapeutic windows. This review will summarise the clinical activity of ADCs in tumour types not covered elsewhere in this issue, such as gastrointestinal (GI) and genitourinary (GU) cancers and glioblastoma (GBM). In addition to the ongoing clinical testing of existing ADCs, there is substantial preclinical and early phase testing of newer ADCs or ADC incorporating strategies. This review will provide selected insights into such future development, focusing on the development of novel ADCs against new antigen targets in the tumour microenvironment (TME) and combination of ADCs with immuno-oncology (IO) agents.

Tumor microenvironment-regulated nanoplatforms for the inhibition of tumor growth and metastasis in chemo-immunotherapy

Chemotherapy is one of the major clinical anticancer therapies. However, its efficiency is limited by many factors, including the complex tumor microenvironment (TME). Herein, manganese-doped mesoporous silica nanoparticles (MM NPs) were constructed and applied to regulate the TME and enhance the efficiency of the combination of chemotherapy and immunotherapy (chemo-immunotherapy). Notably, the combination of MM NPs, doxorubicin hydrochloride, and immune checkpoint inhibitors enhanced the synergistic efficiency of chemo-immunotherapy in a bilateral animal model, which simultaneously inhibited the growth of primary tumors and distant untreated tumors. Moreover, Mn-doping endowed MSNs with six new regulatory functions for the TME by inducing glutathione depletion, ROS generation, oxygenation, cell-killing effect, immune activation, and degradation promotion. These results demonstrated that MM NPs with TME regulatory functions can potentially improve the efficiency of chemo-immunotherapy.

Prognostic Pathways Guide Drug Indications in Pan-Cancers

Pathway-level analysis is a powerful approach enabling the interpretation of post-genomic data at a higher level than that of individual molecules. Molecular-targeted therapy focusing on cascade signaling pathways has become a new paradigm in anticancer therapy, instead of a single protein. However, the approaches to narrowing down the long list of biological pathways are limited. Here, we proposed a strategy for in silico Drug Prescription on biological pathways across pan-Cancers (CDP), by connecting drugs to candidate pathways. Applying on a list of 120 traditional Chinese medicines (TCM), we especially identified the “TCM–pathways–cancers” triplet and constructed it into a heterogeneous network across pan-cancers. Applying them into TCMs, the computational prescribing methods deepened the understanding of the efficacy of TCM at the molecular level. Further applying them into Western medicines, CDP could promote drug reposition avoiding time-consuming developments of new drugs.

Understanding autophagy role in cancer stem cell development

Cancer stem cells (CSCs) are a small subpopulation of immature cells located in the tumor mass. These cells are responsible for tumor development, proliferation, resistance and spreading. CSCs are characterized by three unique features: the ability to self-renew, differentiation and tumor formation. CSCs are similar to stem cells, but they differ in the malignant phenotype. CSCs become immortal and survive harsh environmental conditions such as hypoxia, starvation and oxidative stress. However, this harsh tumor microenvironment induces the activation of autophagy, which further increases the CSCs stemness profile, and all these features further increase tumorigenicity and metastasis capacity. Autophagy is induced by the extracellular and cellular microenvironment. Hypoxia is one of the most common factors that highly increases the activity of autophagy in CSCs. Therefore, hypoxia-induced autophagy and CSCs proliferation should be elucidated in order to find a novel cure to defeat cancer cells (CSCs and non-CSCs). The remaining challenges to close the gap between the laboratory bench and the development of therapies, to use autophagy against CSCs in patients, could be addressed by adopting a 3D platform to better-mimic the natural environment in which these cells reside. Ultimately allowing to obtain the blueprints for bioprocess scaling up and to develop the production pipeline for safe and cost-effective autophagy-based novel biologics.

An emerging role of radiation‑induced exosomes in hepatocellular carcinoma progression and radioresistance (Review)

The incidence rates of hepatocellular carcinoma (HCC) worldwide are increasing, and the role of radiotherapy is currently under discussion. Radioresistance is one of the most important challenges in the therapy of HCC compared with other local advanced, recurrent and metastatic cancers. The mechanisms of radioresistance are complex and remain to be fully understood; however, extracellular vesicles have been investigated in recent studies. Exosomes, which are 40- to 150-nm extracellular vesicles released by cancer cells, contain multiple pathogenic components, including proteins, nucleic acids and lipids, and play critical functions in cancer progression. Emerging data indicate a diagnosis potential for exosomes in HCC, since radiation-derived exosomes promote radioresistance. Radiation-based therapy alters the contents and components of exosomes, suggesting that exosomes and their components may serve as prognostic and predictive biomarkers to monitor radiation response. Therefore, understanding the roles and mechanisms of exosomes in HCC progression and radiation response during HCC therapy may increase our knowledge concerning the roles of exosomes in radioresistance, and may lead to novel approaches for HCC prognosis and treatment. The current review summarizes recent studies on exosome involvement in HCC and the molecular changes in exosome components during HCC progression. It also discusses the functions of exosomes in HCC therapy, and highlights the importance of exosomes in HCC progression and resistance for the development of novel therapies.

Anticancer nanomedicines harnessing tumor microenvironmental components

INTRODUCTION

Small-molecular drugs are extensively used in cancer therapy, while they have issues of nonspecific distribution and consequent side effects. Nanomedicines that incorporate chemotherapeutic drugs have been developed to enhance the therapeutic efficacy of these drugs and reduce their side effects. One of the promising strategies is to prepare nanomedicines by harnessing the unique tumor microenvironment (TME).

AREAS COVERED

The TME contains numerous cell types that specifically express specific antibodies on the surface including tumor vascular endothelial cells, tumor-associated adipocytes, tumor-associated fibroblasts, tumor-associated immune cells and cancer stem cells. The physicochemical environment is characterized with a low pH, hypoxia, and a high redox potential resulting from tumor-specific metabolism. The intelligent nanomedicines can be categorized into two groups: the first group which is rapidly responsive to extracellular chemical/biological factors in the TME and the second one which actively and/or specifically targets cellular components in the TME.

EXPERT OPINION

In this paper, we review recent progress of nanomedicines by harnessing the TME and illustrate the principles and advantages of different strategies for designing nanomedicines, which are of great significance for exploring novel nanomedicines or translating current nanomedicines into clinical practice. We will discuss the challenges and prospects of preparing nanomedicines to utilize or alter the TME for achieving effective, safe anticancer treatment.

Defining Diffuse Large B-Cell Lymphoma Immunotypes by CD8+ T Cells and Natural Killer Cells

Background

There is a poor prognosis for diffuse large B-cell lymphoma (DLBCL), one of the most common types of non-Hodgkin lymphoma (NHL). Through gene expression profiles, this study intends to reveal potential subtypes among patients with DLBCL by evaluating their prognostic impact on immune cells.

Methods

Immune subtypes were developed based on CD8+ T cells and natural killer cells calculated from gene expression profiles. The comparison of prognoses and enriched pathways was made between immune subtypes. Following this validation step, samples from the independent data set were analyzed to determine the correlation between immune subtype and prognosis and immune checkpoint blockade (ICB) response. To provide a model to predict the DLBCL immune subtypes, machine learning methods were used. The virtual screening and molecular docking were adopted to identify small molecules to target the immune subtype biomarkers.

Results

A training data set containing 432 DLBCL samples from five data sets and a testing dataset containing 420 DLBCL samples from GSE10846 were used to develop and validate immune subtypes. There were two novel immune subtypes identified in this study: an inflamed subtype (IS) and a noninflamed subtype (NIS). When compared with NIS, IS was associated with higher levels of immune cells and a better prognosis for immunotherapy. Based on the random forest algorithm, a robust machine learning model has been established by 12 hub genes, and the area under the curve (AUC) value is 0.948. Three small molecules were selected to target NIS biomarkers, including VGF, RAD54L, and FKBP8.

Conclusion

This study assessed immune cells as prognostic factors in DLBCL, constructed an immune subtype that could be used to identify patients who would benefit from ICB, and constructed a model to predict the immune subtype.

Cancer-associated fibroblast exosomes promote chemoresistance to cisplatin in hepatocellular carcinoma through circZFR targeting signal transducers and activators of transcription (STAT3)/ nuclear factor -kappa B (NF-κB) pathway

Chemoresistance in hepatocellular carcinoma (HCC) has been found to be influenced by exosomal transport of circRNAs. However, the role of circZFR in HCC chemoresistance still remains unclear. In the present study, circZFR was highly expressed in cisplatin (DDP)-resistant HCC cell lines and could regulate DDP resistance of the HCC cells. Also, circZFR was highly expressed in cancer-associated fibroblast (CAFs) and the exosome of CAFs. In addition, supplementation of CAFs in culture medium could promote DDP resistance of HCC cells. In vivo tumor xenograft experiments showed that knockdown of circZFR inhibited tumor growth and weakened DDP resistance, while CAFs-derived exosomes incubation increased the expression of circZFR, inhibited the STAT3/NF-κB pathway, promoted tumor growth, and enhanced DDP resistance. In general, CAFs-derived exosomes deliver circZFR to HCC cells, inhibit the STAT3/NF-κB pathway, and promote HCC development and chemoresistance. The results provided a new sight for the prevention and treatment of chemoresistance in HCC.

CX3CR1 Acts as a Protective Biomarker in the Tumor Microenvironment of Colorectal Cancer

The tumor microenvironment (TME) plays an important role in the pathogenesis of many cancers. We aimed to screen the TME-related hub genes of colorectal adenoma (CRAD) and identify possible prognostic biomarkers. The gene expression profiles and clinical data of 464 CRAD patients in The Cancer Genome Atlas (TCGA) database were downloaded. The Estimation of STromal and Immune cells in MAlignant Tumours using Expression data (ESTIMATE) algorithm was performed to calculate the ImmuneScore, StromalScore, and EstimateScore. Thereafter, differentially expressed genes (DEGs) were screened. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and protein–protein interaction (PPI) analysis were performed to explore the roles of DEGs. Furthermore, univariate and multivariate Cox analyses were accomplished to identify independent prognostic factors of CRAD. CX3CR1 was selected as a hub gene, and the expression was confirmed in colorectal cancer (CRC) patients and cell lines. The correlations between CX3CR1 and tumor-infiltrating immune cells were estimated by Tumor IMmune Estimation Resource database (TIMER) and CIBERSORT analysis. Besides, we investigated the effects of coculture with THP-1-derived macrophages with HCT8 cells with low CX3CR1 expression on immune marker expression, cell viability, and migration. There were significant differences in the ImmuneScore and EstimateScore among different stages. Patients with low scores presented significantly lower lifetimes than those in the high-score group. Moreover, we recognized 1,578 intersection genes in ImmuneScore and StromalScore, and these genes were mainly enriched in numerous immune-related biological processes. CX3CR1 was found to be associated with immune cell infiltration levels, immune marker expression, and macrophage polarization. Simultaneous silencing of CX3CR1 and coculture with THP-1 cells further regulated macrophage polarization and promoted the cell proliferation and migration of CRC cells. CX3CR1 was decreased in CRAD tissues and cell lines and was related to T and N stages, tumor differentiation, and prognosis. Our results suggest that CX3CR1 contributes to the recruitment and regulation of immune-infiltrating cells and macrophage polarization in CRC and TAM-induced CRC progression. CX3CR1 may act as a prognostic biomarker in CRC.

MnO2 Coated Nanotheranostic LDH for Synergistic Cascade Chemo/Chemodynamic Cancer Therapy under the Guidance of MRI-Targeted Diagnosis

Integrating magnetic resonance imaging (MRI)-targeted diagnosis with synergistic cascade treatments, such as chemo/chemodynamic therapy (CT/CDT), is highly desired to promote the antitumor performance; However, the rational design of such “all-in-one”...

Multifunctional nanoprobes combined with radiotherapy and hypoxia-activated therapy synergistically improve antitumor efficacy

The developed nanoprobes show a high level of biocompatibility, efficient radiosensitisation and anti-tumour efficacy at the cellular and tissue level.

Construction of a Fibroblast-Associated Tumor Spheroid Model Based on a Collagen Drop Array Chip

Spheroid, a 3D aggregate of tumor cells in a spherical shape, has overcome the limitations of conventional 3D cell models to accurately mimic the in-vivo environment of a human body. The spheroids are cultured with other primary cells and embedded in collagen drops using hang drop plates and low-attachment well plates to construct a spheroid–hydrogel model that better mimics the cell–cell and cell–extracellular matrix (ECM) interactions. However, the conventional methods of culturing and embedding spheroids into ECM have several shortcomings. The procedure of transferring a single spheroid at a time by manual pipetting results in well-to-well variation and even loss or damage of the spheroid. Based on the previously introduced droplet contact-based spheroid transfer technique, we present a poly(dimethylsiloxane) and resin-based drop array chip and a pillar array chip with alignment stoppers, which enhances the alignment between the chips for uniform placement of spheroids. This method allows the facile and stable transfer of the spheroid array and even eliminates the need for a stereomicroscope while handling the cell models. The novel platform demonstrates a homogeneous and time-efficient construction and diverse analysis of an array of fibroblast-associated glioblastoma multiforme spheroids that are embedded in collagen.

Biodegradable Hollow Polydopamine@manganese Dioxide as an Oxygen Self-Supplied Nanoplatform for Boosting Chemo-photodynamic Cancer Therapy

Photodynamic therapy (PDT) has attracted extensive attention in the clinical treatment of malignant tumor. However, the acidic and hypoxic conditions of the tumor microenvironment (TME) limit the further application of PDT in the clinic. Herein, we fabricate a new nanoplatform─HPDA@MnO₂@Ce6/DOX@PEG-RGD (HPMRCD)─by means of coating hollow polydopamine nanoparticles (HPDA) with manganese dioxide (MnO₂), which is modified by cyclic RGD functionalized poly(ethylene glycol) (PEG) and further co-loaded with a photosensitizer, Chlorin e6 (Ce6), and a chemotherapy drug, doxorubicin (DOX). This nanoplatform could be enriched in tumor tissues, then instantly dissociated under an acidic and H₂O₂-rich TME. The dual-responsive release of Mn²⁺ ions and oxygen (O₂) can relieve tumor hypoxia, which can be used as a magnetic resonance contrast agent and the latter can enhance the PDT effect. Furthermore, the degradation of HPMRCD leads to an efficient loaded therapeutic molecule release, thus yielding a potential therapy to enhance tumor suppression by adopting the combined chemo-photodynamic therapy.

Dual-Depletion of Intratumoral Lactate and ATP with Radicals Generation for Cascade Metabolic-Chemodynamic Therapy

Increasing evidence has demonstrated that lactate and adenosine triphosphate (ATP) both play important roles in regulating abnormal metabolism in the tumor microenvironment. Herein, an O2 self-supplying catalytic nanoagent, based on tannic acid (TA)-Fe(III) coordination complexes-coated perfluorooctyl bromide (PFOB) nanodroplets with lactate oxidases (LOX) loading (PFOB@TA-Fe(III)-LOX, PTFL), is designed for cascade metabolic-chemodynamic therapy (CDT) by dual-depletion of lactate and ATP with hydroxyl • OH radicals generation. Benefiting from the catalytic property of loaded LOX and O2 self-supplying of PFOB nanodroplets, PTFL nanoparticles (NPs) efficiently deplete tumoral lactate for down-regulation of vascular endothelial growth factor expression and supplement the insufficient endogenous H2 O2 . Simultaneously, TA-Fe(III) complexes release Fe(III) ions and TA in response to intracellular up-regulated ATP in tumor cells followed by TA-mediated Fe(III)/Fe(II) conversion, leading to the depletion of energy source ATP and the generation of cytotoxic • OH radicals from H2 O2 . Moreover, TA-Fe(III) complexes provide photoacoustic contrast as imaging guidance to enhance therapeutic accuracy. As a result, PTFL NPs efficiently accumulate in tumors for suppression of tumor growth and show evidence of anti-angiogenesis and anti-metastasis effects. This multifunctional nanoagent may provide new insight for targeting abnormal tumor metabolism with the combination of CDT to achieve a synergistic therapeutic effect.

Transformable vesicles for cancer immunotherapy

Immunotherapy that utilizes the human immune system to fight cancer represents a revolutionary method for cancer treatment. Immunotherapeutic agents that trigger the immune response should be carefully delivered to the desired site to maximize immunotherapy effectiveness and minimize side effects. Vesicles offer the possibility of encapsulating both hydrophilic and hydrophobic drugs and thus serve as a promising delivery tool. As multiple irreconcilable requirements exist at different transport stages, developing vesicles transformable in response to given stimuli is of great significance. In this review, we first introduced various vesicle types used for immunotherapy. Furthermore, the typical stimuli that trigger vesicle transformation and the usually generated transformation styles were described. Focusing on three aspects of antigen-presenting cell (APC)/T cell activation, tumor microenvironment (TME) amelioration, and immunogenic cell death (ICD)-induced immunotherapy, we reviewed recently reported transformable vesicles for tumor treatment. Finally, we put forward possible directions for future research and clinical translation.

Novel Insights into the Prognosis and Immunological Value of the SLC35A (Solute Carrier 35A) Family Genes in Human Breast Cancer

According to statistics 2020, female breast cancer (BRCA) became the most commonly diagnosed malignancy worldwide. Prognosis of BRCA patients is still poor, especially in population with advanced or metastatic. Particular functions of each members of the solute carrier 35A (SLC35A) gene family in human BRCA are still unknown regardless of awareness that they play critical roles in tumorigenesis and progression. Using integrated bioinformatics analyses to identify therapeutic targets for specific cancers based on transcriptomics, proteomics, and high-throughput sequencing, we obtained new information and a better understanding of potential underlying molecular mechanisms. Leveraging BRCA dataset that belongs to The Cancer Genome Atlas (TCGA), which were employed to clarify SLC35A gene expression levels. Then we used a bioinformatics approach to investigate biological processes connected to SLC35A family genes in BRCA development. Beside that, the Kaplan-Meier estimator was leveraged to explore predictive values of SLC35A family genes in BCRA patients. Among individuals of this family gene, expression levels of SLC35A2 were substantially related to poor prognostic values, result from a hazard ratio of 1.3 (with 95 percent confidence interval (95% CI: 1.18-1.44), the p for trend (ptrend) is 3.1 × 10-7). Furthermore, a functional enrichment analysis showed that SLC35A2 was correlated with hypoxia-inducible factor 1A (HIF1A), heat shock protein (HSP), E2 transcription factor (E2F), DNA damage, and cell cycle-related signaling. Infiltration levels observed in specific types of immune cell, especially the cluster of differentiation found on macrophages and neutrophils, were positively linked with SLC35A2 expression in multiple BRCA subclasses (luminal A, luminal B, basal, and human epidermal growth factor receptor 2). Collectively, SLC35A2 expression was associated with a lower recurrence-free survival rate, suggesting that it could be used as a biomarker in treating BRCA.

Plasma-Derived Extracellular Vesicles Reveal Galectin-3 Binding Protein as Potential Biomarker for Early Detection of Glioma

Gliomas are the most common type of the malignant brain tumor, which arise from glial cells. They make up about 40% of all primary brain tumors and around 70% of all primary malignant brain tumors. They can occur anywhere in the central nervous system (CNS) and have a poor prognosis. The average survival of glioma patients is approximately 6-15 months with poor aspects of life. In this edge, identification of proteins secreted by cancer cells is of special interest because it may provide a better understanding of tumor progression and provide early diagnosis of the diseases. Extracellular vesicles (EVs) were isolated from pooled plasma of healthy controls (n=03) and patients with different grades of glioma (Grade I or II or III, n=03 each). Nanoparticle tracking analysis, western blot, and flow cytometry were performed to determine the size, morphology, the concentration of glioma-derived vesicles and EV marker, CD63. Further, iTRAQ-based LC-MS/MS analysis of EV protein was performed to determine the differential protein abundance in extracellular vesicles across different glioma grades. We further verified galectin-3 binding protein (LGALS3BP) by ELISA in individual blood plasma and plasma-derived vesicles from control and glioma patients (n=40 each). Analysis by Max Quant identified 123 proteins from the pooled patient exosomes, out of which 34, 21, and 14 proteins were found to be differentially abundant by more than 1.3-fold in the different grades of glioma grade I, pilocytic astrocytoma; grade II, diffuse astrocytoma; grade III, anaplastic astrocytoma, respectively, in comparison with the control samples. A total of seven proteins-namely, CRP, SAA2, SERPINA3, SAA1, C4A, LV211, and KV112-showed differential abundance in all the three grades. LGALS3BP was seen to be upregulated across the different grades, and ELISA analysis from individual blood plasma and plasma-derived extracellular vesicles confirmed the increased expression of LGALS3BP in glioma patients (p<0.001). The present study provides LGALS3BP as a potential biomarker for early detection of glioma and improve survival outcome of the patient. The present study further provides the information of progression and monitoring the tumor grades (grade 1, grade II, grade III).

Proteomic Analysis Identifies FNDC1, A1BG, and Antigen Processing Proteins Associated with Tumor Heterogeneity and Malignancy in a Canine Model of Breast Cancer

New insights into the underlying biological processes of breast cancer are needed for the development of improved markers and treatments. The complex nature of mammary cancer in dogs makes it a great model to study cancer biology since they present a high degree of tumor heterogeneity. In search of disease-state biomarkers candidates, we applied proteomic mass spectrometry imaging in order to simultaneously detect histopathological and molecular alterations whilst preserving morphological integrity, comparing peptide expression between intratumor populations in distinct levels of differentiation. Peptides assigned to FNDC1, A1BG, and double-matching keratins 18 and 19 presented a higher intensity in poorly differentiated regions. In contrast, we observed a lower intensity of peptides matching calnexin, PDIA3, and HSPA5 in poorly differentiated cells, which enriched for protein folding in the endoplasmic reticulum and antigen processing, assembly, and loading of class I MHC. Over-representation of collagen metabolism, coagulation cascade, extracellular matrix components, cadherin-binding and cell adhesion pathways also distinguished cell populations. Finally, an independent validation showed FNDC1, A1BG, PDIA3, HSPA5, and calnexin as significant prognostic markers for human breast cancer patients. Thus, through a spatially correlated characterization of spontaneous carcinomas, we described key proteins which can be further validated as potential prognostic biomarkers.

Comprehensive analysis of immune related lncRNAs in the tumor microenvironment of stage II-III colorectal cancer

Background

Long non-coding RNAs (lncRNAs) associated with immunological function have increasingly been found to act as effective prognostic biomarkers of the overall survival (OS) of colorectal cancer (CRC) patients. We sought to identify a signature of immune-related lncRNAs that offered value as a tool for the prospective prognostic evaluation of patients with stage II-III CRC.

Methods

The clinical and gene expression data of CRC patients in The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases was obtained and separated into a training cohort composed of 202 samples, a test cohort of 124 samples from the GSE72970 dataset, and a validation cohort of 91 samples from the GSE143985 dataset.

Results

We firstly evaluated intratumoral immune cell infiltration by conducting a Single-sample gene set enrichment analyses (ssGSEA) analysis to separate patient tumors into those with low immune cell infiltration and those with high immune cell infiltration. We then compared lncRNA and mRNA expression profiles between these two tumor types, leading us to focus on eight lncRNAs identified within the resultant mRNA-lncRNA co-expression network. Multivariate Cox regression models were then utilized to detect an immune-associated lncRNA signature that offered value for prognostic model construction. Functional analyses revealed this lncRNA signature to be associated with key immunological pathways including the JAK-STAT signaling, T cell receptor signaling, and Rap1 signaling pathways.

Conclusions

Together, our results suggest that our immune-related 4 lncRNA signature can reliably predict stage II-III CRC patient prognosis, thereby guiding efforts to better understand this disease and to effectively treat it.

The role of Globo H and SSEA-4 in the development and progression of cancer, and their potential as therapeutic targets

Glycans, chains of sugar molecules found conjugated to cell proteins and lipids, contribute to their growth, movement and differentiation. Aberrant glycosylation is a hallmark of several medical conditions including tumorigenesis. Glycosphingolipids (GSLs), consisting of glycans conjugated to a lipid (ceramide) core, are found in the lipid bilayer of eukaryotic cell membranes. GSLs, play an active role in cell processes. Several GSLs are expressed by human embryonic stem cells and have been found to be overexpressed in several types of cancer. In this review, we discuss the data, hypotheses and perspectives related to the GSLs Globo H and SSEA-4.

A Different Facet of p53 Function: Regulation of Immunity and Inflammation During Tumor Development

As a key transcription factor, the evolutionarily conserved tumor suppressor p53 (encoded by TP53) plays a central role in response to various cellular stresses. A variety of biological processes are regulated by p53 such as cell cycle arrest, apoptosis, senescence and metabolism. Besides these well-known roles of p53, accumulating evidence show that p53 also regulates innate immune and adaptive immune responses. p53 influences the innate immune system by secreted factors that modulate macrophage function to suppress tumourigenesis. Dysfunction of p53 in cancer affects the activity and recruitment of T and myeloid cells, resulting in immune evasion. p53 can also activate key regulators in immune signaling pathways which support or impede tumor development. Hence, it seems that the tumor suppressor p53 exerts its tumor suppressive effect to a considerable extent by modulating the immune response. In this review, we concisely discuss the emerging connections between p53 and immune responses, and their impact on tumor progression. Understanding the role of p53 in regulation of immunity will help to developing more effective anti-tumor immunotherapies for patients with TP53 mutation or depletion.

A Multifunctional Polymeric Micelle for Targeted Delivery of Paclitaxel by the Inhibition of the P-Glycoprotein Transporters

P-glycoprotein (P-gP) efflux-mediated multidrug resistance is a fundamental aspect of chemotherapeutic failure in oncology. The current study aims to deliver paclitaxel (PTX) specifically at the target site with improved in vivo efficacy of poorly permeable PTX against solid tumors. Multifunctional polymeric micelles as targeted delivery have been devised for loading and release of PTX. Mucoadhesion, permeation enhancement, oral pharmacokinetics, biodistribution, and toxicological studies were carried out to fully elucidate the therapeutic outcomes of the polymeric micelles. Ex vivo permeation studies indicated a 7.89-fold enhancement in the permeation of PTX with mucopermeating papain functionalized thiolated redox micelles (PT-R-Ms) compared to the pure PTX. Moreover, PT-R-Ms exhibited a higher percentage of apoptotic cells (42.9 ± 0.07%) compared to pure PTX. Biodistribution studies revealed that fluorotagged PT-RMs accumulated in excised tumors and organs. The higher fluorescence intensity indicated the mucopermeation of micelles across the intestine. The orally administered PT-R-Ms efficiently overcome intestinal barriers and inhibit the P-gP efflux pump, resulting in increased bioavailability of PTX (up to 8-fold) in comparison to pure PTX. The enhanced anti-tumor efficacy and reduced toxic effects are key aspects of efficient cancer therapy. This study demonstrates that the use of mucopermeating PT-R-Ms is an encouraging approach to overwhelm the permeation barrier in cancer treatment.

Sex-Based Differences in the Tumor Microenvironment

Cancers are heterogeneous multifactorial diseases consisting of a major public health issue worldwide. Sex disparities are evidenced in cancer incidence, mortality, expression of prognosis factor, response to treatment, and survival. For both sexes, an interplay of intrinsic and environmental factors influences cancer cells and tumor microenvironment (TME) components. The TME cumulates both supportive and communicative functions, contributing to cancer development, progression, and metastasis dissemination. The frontline topics of this chapter are focused on the contribution of sex, via steroid hormones, such as estrogens and androgens, on the following components of the TME: cancer-associated fibroblasts (CAFs), extracellular matrix (ECM), blood and lymphatic endothelial cells, and immunity/inflammatory system.

Small Extracellular Vesicles: Functions and Potential Clinical Applications as Cancer Biomarkers

Cancer, as the second leading cause of death worldwide, is a major public health concern that imposes a heavy social and economic burden. Effective approaches for either diagnosis or therapy of most cancers are still lacking. Dynamic monitoring and personalized therapy are the main directions for cancer research. Cancer-derived extracellular vesicles (EVs) are potential disease biomarkers. Cancer EVs, including small EVs (sEVs), contain unique biomolecules (protein, nucleic acid, and lipids) at various stages of carcinogenesis. In this review, we discuss the biogenesis of sEVs, and their functions in cancer, revealing the potential applications of sEVs as cancer biomarkers.

L-EGCG-Mn nanoparticles as a pH-sensitive MRI contrast agent

This study aimed to synthesize and characterize L-epigallocatechin gallate (EGCG) complexed Mn²⁺ nanoparticle (L-EGCG-Mn), a proof-of-concept pH-sensitive manganese core nanoparticle (NP), and compare its magnetic resonance (MR) properties with those of Gd-DTPA, both in vitro and in vivo. Reverse microemulsion was used to obtain the L-EGCG-Mn NPs. The physicochemical properties of L-EGCG-Mn were characterized using dynamic light scattering, transmission electron microscopy, and near-infrared fluorescence small animal live imaging. The in vitro relaxivity of L-EGCG-Mn incubated with different pH buffer solutions (pH = 7.4, 6.8, 5.5) was evaluated. The T1-weighted MR imaging (MRI) properties were evaluated in vitro using hypoxic H22 cells as well as in H22 tumor-bearing mice. Cytotoxicity tests and histological analysis were performed to evaluate the safety of L-EGCG-Mn. L-EGCG-Mn showed good biocompatibility, stability, pH sensitivity, and tumor-targeting ability. Moreover, when the pH was decreased from 7.4 to 5.5, the r ₁ relaxivity of L-EGCG-Mn was shown to gradually increase from 1.79 to 6.43 mM^-1·s^-1. Furthermore, after incubation with L-EGCG-Mn for 4 h, the T1 relaxation time of hypoxic H22 cells was significantly lower than that of normoxic H22 cells (1788 ± 89 vs. 1982 ± 68 ms, p=.041). The in vivo analysis showed that after injection, L-EGCG-Mn exhibited a higher MRI signal compared to Gd-DTPA in H22 tumor-bearing mice (p < .05). Furthermore, L-EGCG-Mn was found to have a good safety profile via cytotoxicity tests and histological analysis. L-EGCG-Mn has a good safety profile and pH sensitivity and may thus serve as a potential MRI contrast agent.

Single-Cell Analysis Reveals Spatial Heterogeneity of Immune Cells in Lung Adenocarcinoma

The impacts of the tumor microenvironment (TME) on tumor evolvability remain unclear. A challenge for nearly all cancer types is spatial heterogeneity, providing substrates for the emergence and evolvability of drug resistance and leading to unfavorable prognosis. Understanding TME heterogeneity among different tumor sites would provide deeper insights into personalized therapy. We found 9,992 cell profiles of the TME in human lung adenocarcinoma (LUAD) samples at a single-cell resolution. By comparing different tumor sites, we discovered high TME heterogeneity. Single-sample gene set enrichment analysis (ssGSEA) was utilized to explore functional differences between cell subpopulations and between the core, middle and edge of tumors. We identified 8 main cell types and 27 cell subtypes of T cells, B cells, fibroblasts and myeloid cells. We revealed CD4+ naive T cells in the tumor core that express high levels of immune checkpoint molecules and have a higher activity of immune-exhaustion signaling. CD8+ T cell subpopulations in the tumor core correlate with the upregulated activity of transforming growth factor-β (TGF-β) and fibroblast growth factor receptor (FGFR) signaling and downregulated T cell activity. B cell subtypes in the tumor core downregulate cytokine production. In this study, we revealed that there was immunological heterogeneity in the TME of patients with LUAD that have different ratios of immune cells and stromal cells, different functions, and various degrees of activation of immune-related pathways in different tumor parts. Therefore, clarifying the spatial heterogeneity of the tumor in the immune microenvironment can help clinicians design personalized treatments.

Tumor-on-a-chip: from bioinspired design to biomedical application

Cancer is one of the leading causes of human death, despite enormous efforts to explore cancer biology and develop anticancer therapies. The main challenges in cancer research are establishing an efficient tumor microenvironment in vitro and exploring efficient means for screening anticancer drugs to reveal the nature of cancer and develop treatments. The tumor microenvironment possesses human-specific biophysical and biochemical factors that are difficult to recapitulate in conventional in vitro planar cell models and in vivo animal models. Therefore, model limitations have hindered the translation of basic research findings to clinical applications. In this review, we introduce the recent progress in tumor-on-a-chip devices for cancer biology research, medicine assessment, and biomedical applications in detail. The emerging tumor-on-a-chip platforms integrating 3D cell culture, microfluidic technology, and tissue engineering have successfully mimicked the pivotal structural and functional characteristics of the in vivo tumor microenvironment. The recent advances in tumor-on-a-chip platforms for cancer biology studies and biomedical applications are detailed and analyzed in this review. This review should be valuable for further understanding the mechanisms of the tumor evolution process, screening anticancer drugs, and developing cancer therapies, and it addresses the challenges and potential opportunities in predicting drug screening and cancer treatment.

A Tumor Progression Related 7-Gene Signature Indicates Prognosis and Tumor Immune Characteristics of Gastric Cancer

BACKGROUND

Gastric cancer is a common gastrointestinal malignancy. Since it is often diagnosed in the advanced stage, its mortality rate is high. Traditional therapies (such as continuous chemotherapy) are not satisfactory for advanced gastric cancer, but immunotherapy has shown great therapeutic potential. Gastric cancer has high molecular and phenotypic heterogeneity. New strategies for accurate prognostic evaluation and patient selection for immunotherapy are urgently needed.

METHODS

Weighted gene coexpression network analysis (WGCNA) was used to identify hub genes related to gastric cancer progression. Based on the hub genes, the samples were divided into two subtypes by consensus clustering analysis. After obtaining the differentially expressed genes between the subtypes, a gastric cancer risk model was constructed through univariate Cox regression, least absolute shrinkage and selection operator (LASSO) regression and multivariate Cox regression analysis. The differences in prognosis, clinical features, tumor microenvironment (TME) components and immune characteristics were compared between subtypes and risk groups, and the connectivity map (CMap) database was applied to identify potential treatments for high-risk patients.

RESULTS

WGCNA and screening revealed nine hub genes closely related to gastric cancer progression. Unsupervised clustering according to hub gene expression grouped gastric cancer patients into two subtypes related to disease progression, and these patients showed significant differences in prognoses, TME immune and stromal scores, and suppressive immune checkpoint expression. Based on the different expression patterns between the subtypes, we constructed a gastric cancer risk model and divided patients into a high-risk group and a low-risk group based on the risk score. High-risk patients had a poorer prognosis, higher TME immune/stromal scores, higher inhibitory immune checkpoint expression, and more immune characteristics suitable for immunotherapy. Multivariate Cox regression analysis including the age, stage and risk score indicated that the risk score can be used as an independent prognostic factor for gastric cancer. On the basis of the risk score, we constructed a nomogram that relatively accurately predicts gastric cancer patient prognoses and screened potential drugs for high-risk patients.

CONCLUSIONS

Our results suggest that the 7-gene signature related to tumor progression could predict the clinical prognosis and tumor immune characteristics of gastric cancer.

Role of Exosomal Non-coding RNAs in Gastric Cancer: Biological Functions and Potential Clinical Applications

Gastric cancer (GC) is one of the most common fatal cancers worldwide. The communication between GC and other cells in the GC microenvironment directly affects GC progression. Recently, exosomes have been revealed as new players in intercellular communication. They play an important role in human health and diseases, including cancer, owing to their ability to carry various bioactive molecules, including non-coding RNAs (ncRNAs). NcRNAs, including micro RNAs, long non-coding RNAs, and circular RNAs, play a significant role in various pathophysiological processes, especially cancer. Increasing evidence has shown that exosomal ncRNAs are involved in the regulation of tumor proliferation, invasion, metastasis, angiogenesis, immune regulation, and treatment resistance in GC. In addition, exosomal ncRNAs have promising potential as diagnostic and prognostic markers for GC. Considering the biocompatibility of exosomes, they can also be used as biological carriers for targeted therapy. This review summarizes the current research progress on exosomal ncRNAs in gastric cancer, focusing on their biological role in GC and their potential as new biomarkers for GC and therapeutics. Our review provides insight into the mechanisms involved in GC progression, which may provide a new point cut for the discovery of new diagnostic markers and therapeutic strategies.

Smart Cargo Delivery System based on Mesoporous Nanoparticles for Bone Disease Diagnosis and Treatment

Bone diseases constitute a major issue for modern societies as a consequence of progressive aging. Advantages such as open mesoporous channel, high specific surface area, ease of surface modification, and multifunctional integration are the driving forces for the application of mesoporous nanoparticles (MNs) in bone disease diagnosis and treatment. To achieve better therapeutic effects, it is necessary to understand the properties of MNs and cargo delivery mechanisms, which are the foundation and key in the design of MNs. The main types and characteristics of MNs for bone regeneration, such as mesoporous silica (mSiO2 ), mesoporous hydroxyapatite (mHAP), mesoporous calcium phosphates (mCaPs) are introduced. Additionally, the relationship between the cargo release mechanisms and bone regeneration of MNs-based nanocarriers is elucidated in detail. Particularly, MNs-based smart cargo transport strategies such as sustained cargo release, stimuli-responsive (e.g., pH, photo, ultrasound, and multi-stimuli) controllable delivery, and specific bone-targeted therapy for bone disease diagnosis and treatment are analyzed and discussed in depth. Lastly, the conclusions and outlook about the design and development of MNs-based cargo delivery systems in diagnosis and treatment for bone tissue engineering are provided to inspire new ideas and attract researchers' attention from multidisciplinary areas spanning chemistry, materials science, and biomedicine.

Stimulus-responsive liposomes for biomedical applications

Liposomes are amphipathic lipidic supramolecular aggregates that are able to encapsulate and carry molecules of both hydrophilic and hydrophobic nature. They have been widely used as in vivo drug delivery systems for some time because they offer features such as synthetic flexibility, biodegradability, biocompatibility, low immunogenicity, and negligible toxicity. In recent years, the chemical modification of liposomes has paved the way to the development of smart liposome-based drug delivery systems, which are characterized by even more tunable and disease-directed features. In this review, we highlight the different types of chemical modification introduced to date, with a particular focus on internal stimuli-responsive liposomes and prodrug activation.

Functions and Targets of miR-335 in Cancer

MicroRNAs (miRNAs) are small non-coding RNAs (18~25 nt in length) that act as master regulators of eukaryotic gene expression. They might play an oncogenic or tumor-suppressive role in multiple cancers. In recent decades, several studies have focused on the functions and mechanisms of miR-335 in cancer. The expression level of miR-335 in tissues and cells varies with cancer types, and miR-335 has been proposed as a potential biomarker for the prognosis of cancer. Besides, miR-335 may serve as an oncogene or tumor suppressor via regulating different targets or pathways in tumor initiation, development, and metastasis. Furthermore, miR-335 also influences tumor microenvironment and drug sensitivity. MiR-335 is regulated by various factors such as lncRNAs and microRNAs. In this review, we reveal the functions and targets of miR-335 in various cancers and its potential application as a possible biomarker in prognostic judgment and treatment of malignant tumors.

Identification of the hub genes and prognostic indicators of gastric cancer and correlation of indicators with tumor-infiltrating immune cell levels

Aims: To identify the hub genes and prognostic indicators of gastric cancer (GC) and determine the correlation between prognostic indicators and the tumor-infiltrating immune cell levels so as to provide useful information for future GC diagnosis and treatment. Methods: The Cancer Genome Atlas (TCGA) stomach adenocarcinoma dataset and two microarray datasets were used to screen the overlapping differentially expressed genes (DEGs) between normal gastric and GC tissue samples. Hub genes were screened via protein-protein interaction networks and module analysis of the overlapping DEGs. Their expression was validated at the cell level and tissue level using the ONCOMINE database. The prognostic indicators of overall survival (OS) and disease-free survival was identified by Cox proportional hazards regression analysis based on tumor grade and cancer stage. The expression of hub genes was validated at the cell level. The correlation of prognostic indicators with the tumor-infiltrating immune cell levels was analyzed using Tumor IMmune Estimation Resource. Results: Ten hub genes, namely CDC6, CDC20, BUB1B, TOP2A, CDK1, AURKA, CCNA2, CCNB1, MAD2L1, and KIF11, were screened and their upregulation in the GC tissue was verified. Three prognostic factors, namely LUM, VCAN, and EFNA4, were identified; their expression was higher in GC cells than in normal cells. LUM, VCAN, and EFNA4 were correlated with tumor-infiltrating immune cell levels in GC. Significance: The identified hub genes and prognostic indicators of GC could be useful indicators for future GC diagnosis and treatment.

Cross talk between autophagy and oncogenic signaling pathways and implications for cancer therapy

Autophagy is a highly conserved metabolic process involved in the degradation of intracellular components including proteins and organelles. Consequently, it plays a critical role in recycling metabolic energy for the maintenance of cellular homeostasis in response to various stressors. In cancer, autophagy either suppresses or promotes cancer progression depending on the stage and cancer type. Epithelial-mesenchymal transition (EMT) and cancer metastasis are directly mediated by oncogenic signal proteins including SNAI1, SLUG, ZEB1/2, and NOTCH1, which are functionally correlated with autophagy. In this report, we discuss the crosstalk between oncogenic signaling pathways and autophagy followed by possible strategies for cancer treatment via regulation of autophagy. Although autophagy affects EMT and cancer metastasis, the overall signaling pathways connecting cancer progression and autophagy are still illusive. In general, autophagy plays a critical role in cancer cell survival by providing a minimum level of energy via self-digestion. Thus, cancer cells face nutrient limitations and challenges under stress during EMT and metastasis. Conversely, autophagy acts as a potential cancer suppressor by degrading oncogenic proteins, which are essential for cancer progression, and by removing damaged components such as mitochondria to enhance genomic stability. Therefore, autophagy activators or inhibitors represent possible cancer therapeutics. We further discuss the regulation of autophagy-dependent degradation of oncogenic proteins and its functional correlation with oncogenic signaling pathways, with potential applications in cancer therapy.

Microfluidic Reconstitution of Tumor Microenvironment for Nanomedical Applications

Nanoparticles have an extensive range of diagnostic and therapeutic applications in cancer treatment. However, their current clinical translation is slow, mainly due to the failure to develop preclinical evaluation techniques that can draw similar conclusions to clinical outcomes by adequately mimicking nanoparticle behavior in complicated tumor microenvironments (TMEs). Microfluidic methods offer significant advantages over conventional in vitro methods to resolve these challenges by recapitulating physiological cues of the TME such as the extracellular matrix, shear stress, interstitial flow, soluble factors, oxygen, and nutrient gradients. The methods are capable of de-coupling microenvironmental features, spatiotemporal controlling of experimental sequences, and high throughput readouts in situ. This progress report highlights the recent achievements of microfluidic models to reconstitute the physiological microenvironment, especially for nanomedical tools for cancer treatment.

A 9-kDa matricellular SPARC fragment released by cathepsin D exhibits pro-tumor activity in the triple-negative breast cancer microenvironment

Rationale: Alternative therapeutic strategies based on tumor-specific molecular targets are urgently needed for triple-negative breast cancer (TNBC). The protease cathepsin D (cath-D) is a marker of poor prognosis in TNBC and a tumor-specific extracellular target for antibody-based therapy. The identification of cath-D substrates is crucial for the mechanistic understanding of its role in the TNBC microenvironment and future therapeutic developments.

Methods: The cath-D substrate repertoire was investigated by N-Terminal Amine Isotopic Labeling of Substrates (TAILS)-based degradome analysis in a co-culture assay of TNBC cells and breast fibroblasts. Substrates were validated by amino-terminal oriented mass spectrometry of substrates (ATOMS). Cath-D and SPARC expression in TNBC was examined using an online transcriptomic survival analysis, tissue micro-arrays, TNBC cell lines, patient-derived xenografts (PDX), human TNBC samples, and mammary tumors from MMTV-PyMT Ctsd^-/-knock-out mice. The biological role of SPARC and its fragments in TNBC were studied using immunohistochemistry and immunofluorescence analysis, gene expression knockdown, co-culture assays, western blot analysis, RT-quantitative PCR, adhesion assays, Transwell motility, trans-endothelial migration and invasion assays.

Results: TAILS analysis showed that the matricellular protein SPARC is a substrate of extracellular cath-D. In vitro, cath-D induced limited proteolysis of SPARC C-terminal extracellular Ca²⁺ binding domain at acidic pH, leading to the production of SPARC fragments (34-, 27-, 16-, 9-, and 6-kDa). Similarly, cath-D secreted by TNBC cells cleaved fibroblast- and cancer cell-derived SPARC at the tumor pericellular acidic pH. SPARC cleavage also occurred in TNBC tumors. Among these fragments, only the 9-kDa SPARC fragment inhibited TNBC cell adhesion and spreading on fibronectin, and stimulated their migration, endothelial transmigration, and invasion.

Conclusions: Our study establishes a novel crosstalk between proteases and matricellular proteins in the tumor microenvironment through limited SPARC proteolysis, revealing a novel targetable 9-kDa bioactive SPARC fragment for new TNBC treatments. Our study will pave the way for the development of strategies for targeting bioactive fragments from matricellular proteins in TNBC.

Hybrid nanoparticle composites applied to photodynamic therapy: strategies and applications

Photodynamic therapy (PDT), as a robust strategy, has long been applied to cancer treatment owing to the meaningful breakthroughs and unique advantages, including ignorable invasiveness and spatio-temporal selectivity. Numerous PDT agents, especially hybrid nanoparticle composite (hybrid)-based sensitizers consisting of an organic polymer and inorganic nanoparticles (NPs), feature the synergetic pros of the components, which have unlocked the additional potentials of PDT. Although reviews relating to the applications of hybrids to PDT have been previously reported, most of them only focus on the designs of smart hybrids integrating multimodal imaging-guided multiple treatment modalities. Traditional PDT treatment has several limitations, such as inadequate PDT agents accumulating in cancer tissues, inferior PDT effect due to the devastating cancer hypoxia environment, relevant systemic toxicity in non-intelligent stimulation response treatment systems, and serious dependence of PDT on external light sources. Many strategies have been developed for overcoming these limitations, including improvement of cancer-homing ability by introducing active targeting groups, remodeling of the cancer hypoxia environment through oxygen regulators, intratumor release of ROS through activatable molecules, and replacement of laser light by X-rays or self-luminescence. This review aims to summarize the most recent advances in designing hybrids for improving the therapeutic efficacy of PDT.

Poly(Ethylene Glycol)-Poly(l-Alanine)/Hyaluronic Acid Complex as a 3D Platform for Understanding Cancer Cell Migration in the Tumor Microenvironment

Cancer progression and migration in the tumor microenvironment are related to cell types and three-dimensional (3D) matrices. Therefore, developing biomimetic tumor models, including co-culture systems and a tunable 3D matrix, could play an essential role in understanding the cancer environment. Here, multicellular spheroids using human adipose-derived mesenchymal stem cells (hADSCs) and breast cancer cells (MDA-MB-231) within the 3D matrix were used as a tumor microenvironment (TME) mimicking platform. The amphiphilic peptide block copolymer and hyaluronic acid (HA) formed a self-assembled structure, which provides a biocompatible 3D environment for the cells. Multicellular spheroids were formed on the optimized plate and were observed as cell migration from a spheroid within a 3D matrix, such as the invasive and metastatic cancer of TME. This study suggests a new 3D platform using polymer complexes and the importance of tumor complexities, including various cell types and microenvironments.

Establishment and characterization of HXWMF-1: the first mouse fibroblastic tumor cell line derived from leukemia-associated fibroblasts

Background

Chemo-resistance is still a major obstacle in leukemia treatment. Accumulating evidence indicates that cancer-associated fibroblasts (CAFs), the most abundant stromal cells in tumor microenvironment (TME), play a crucial role in cancer progression and response to chemotherapy. To Figure out the role of leukemia-associated fibroblasts (LAFs) in relapsed/refractory leukemia, we constructed the first leukemia-associated fibroblastic tumor cell line, HXWMF-1.

Methods

A cell culture technique was used to establish the leukemia-associated fibroblastic tumor cell line. Molecular and cellular biological techniques including flow cytometry, MTT assay, western blotting, and short tandem repeat (STR) analysis were used to characterize the cell line. Nude mice were used for xenograft studies.

Results

We established a LAFs derived tumor cell line HXWMF-1, originated from the subcutaneous xenografts of HXEX-ALL1, a cell line originated from a patient with acute lymphoblastic leukemia (ALL) at the second relapse. The HXWMF-1 cell line was authenticated as a tumor cell line and being derived from CAFs based on morphologic, immunophenotypic, cytogenetic and STR analyses and tumorigenicity test in nude mice. To clarify the reliability of the method, we got the LAFs derived tumor cells from three different tumor mass of HXEX-ALL1 xenografts.

Conclusions

To our knowledge, HXWMF-1 is the first fibroblastic tumor cell line derived from LAFs or CAFs. In addition, the cell line provided firm evidence for that leukemia cells may induce LAFs/CAFs malignant transformation, which may help to develop brand new theory and therapeutic strategies for patients with relapsed /refractory ALL.

Autophagy in Viral Development and Progression of Cancer

Autophagy is a complex degradative process by which eukaryotic cells capture cytoplasmic components for subsequent degradation through lysosomal hydrolases. Although this catabolic process can be triggered by a great variety of stimuli, action in cells varies according to cellular context. Autophagy has been previously linked to disease development modulation, including cancer. Autophagy helps suppress cancer cell advancement in tumor transformation early stages, while promoting proliferation and metastasis in advanced settings. Oncoviruses are a particular type of virus that directly contribute to cell transformation and tumor development. Extensive molecular studies have revealed complex ways in which autophagy can suppress or improve oncovirus fitness while still regulating viral replication and determining host cell fate. This review includes recent advances in autophagic cellular function and emphasizes its antagonistic role in cancer cells.

Autophagy in Viral Development and Progression of Cancer

Autophagy is a complex degradative process by which eukaryotic cells capture cytoplasmic components for subsequent degradation through lysosomal hydrolases. Although this catabolic process can be triggered by a great variety of stimuli, action in cells varies according to cellular context. Autophagy has been previously linked to disease development modulation, including cancer. Autophagy helps suppress cancer cell advancement in tumor transformation early stages, while promoting proliferation and metastasis in advanced settings. Oncoviruses are a particular type of virus that directly contribute to cell transformation and tumor development. Extensive molecular studies have revealed complex ways in which autophagy can suppress or improve oncovirus fitness while still regulating viral replication and determining host cell fate. This review includes recent advances in autophagic cellular function and emphasizes its antagonistic role in cancer cells.