Interfering cellular lactate homeostasis overcomes Taxol resistance of breast cancer cells through the microRNA-124-mediated lactate transporter (MCT1) inhibition

Lysine lactylation in the regulation of tumor biology

Lysine lactylation (Kla), a newly discovered post-translational modification (PTM) of lysine residues, is progressively revealing its crucial role in tumor biology. A growing body of evidence supports its capacity of transcriptional regulation through histone modification and modulation of non-histone protein function. It intricately participates in a myriad of events in the tumor microenvironment (TME) by orchestrating the transitions of immune states and augmenting tumor malignancy. Its preferential modification of metabolic proteins underscores its specific regulatory influence on metabolism. This review focuses on the effect and the probable mechanisms of Kla-mediated regulation of tumor metabolism, the upstream factors that determine Kla intensity, and its potential implications for the clinical diagnosis and treatment of tumors.

Extracellular vesicles as modulators of glioblastoma progression and tumor microenvironment

Glioblastoma is the most aggressive brain tumor with extremely poor prognosis in adults. Routine treatments include surgery, chemotherapy, and radiotherapy; however, these may lead to rapid relapse and development of therapy-resistant tumor. Glioblastoma cells are known to communicate with macrophages, microglia, endothelial cells, astrocytes, and immune cells in the tumor microenvironment (TME) to promote tumor preservation. It was recently demonstrated that Glioblastoma-derived extracellular vesicles (EVs) participate in bidirectional intercellular communication in the TME. Apart from promoting glioblastoma cell proliferation, migration, and angiogenesis, EVs and their cargos (primarily proteins and miRNAs) can act as biomarkers for tumor diagnosis and prognosis. Furthermore, they can be used as therapeutic tools. In this review, the mechanisms of Glioblastoma-EVs biogenesis and intercellular communication with TME have been summarized. Moreover, there is discussion surrounding EVs as novel diagnostic structures and therapeutic tools for glioblastoma. Finally, unclear questions that require future investigation have been reviewed.

SETDB1 Methylates MCT1 Promoting Tumor Progression by Enhancing the Lactate Shuttle

MCT1 is a critical protein found in monocarboxylate transporters that plays a significant role in regulating the lactate shuttle. However, the post-transcriptional modifications that regulate MCT1 are not clearly identified. In this study, it is reported that SETDB1 interacts with MCT1, leading to its stabilization. These findings reveal a novel post-translational modification of MCT1, in which SETDB1 methylation occurs at K473 in vitro and in vivo. This methylation inhibits the interaction between MCT1 and Tollip, which blocks Tollip-mediated autophagic degradation of MCT1. Furthermore, MCT1 K473 tri-methylation promotes tumor glycolysis and M2-like polarization of tumor-associated macrophages in colorectal cancer (CRC), which enhances the lactate shuttle. In clinical studies, MCT1 K473 tri-methylation is found to be upregulated and positively correlated with tumor progression and overall survival in CRC. This discovery suggests that SETDB1-mediated tri-methylation at K473 is a vital regulatory mechanism for lactate shuttle and tumor progression. Additionally, MCT1 K473 methylation may be a potential prognostic biomarker and promising therapeutic target for CRC.

MicroRNA (miR)-124: A Promising Therapeutic Gateway for Oncology

MicroRNA (miR) are a class of small non-coding RNA that are involved in post-transcriptional gene regulation. Altered expression of miR has been associated with several pathological conditions. MicroRNA-124 (miR-124) is an abundantly expressed miR in the brain as well as the thymus, lymph nodes, bone marrow, and peripheral blood mono-nuclear cells. It plays a key role in the regulation of the host immune system. Emerging studies show that dysregulated expression of miR-124 is a hallmark in several cancer types and it has been attributed to the progression of these malignancies. In this review, we present a comprehensive summary of the role of miR-124 as a promising therapeutic gateway in oncology.

Comprehensive analysis of pan-cancer reveals the potential of SLC16A1 as a prognostic and immunological biomarker

SLC16A1 plays an important role in the development of multiple cancer types. Pan-cancer analysis may have significant impacts on the exploration of the relationship between SLC16A1 gene expression, prognosis and the molecular mechanisms of tumorigenesis. In this study, through the analysis of TCGA and GEO datasets, we explored the expression level and survival prognosis of SLC16A1 in pan-cancer, and further explored the differences in SLC16A1 gene mutation, methylation, and phosphorylation between tumor and normal tissues. In addition, we focused on the biological function of this gene and the relationship between the prognosis and immune infiltration by immune infiltration analysis and enrichment analysis, in order to evaluate the diagnostic and prognostic significance of SLC16A1 in carcinomas. The study found that SLC16A1 was highly expressed in 14 kinds of tumors, and there were statistically significant differences in the prognosis of 9 tumors. The phosphorylation level of S467 increased in OV, RCC, and UCEC. There was a statistically negative correlation between the CD8+ T-cell infiltration level and the SLC16A1 expression in HNSC, LUSC, SARC, TGCT, and KIRC. The cancer-related fibroblasts were positively correlated with SLC16A1 expression in BLCA, BRCA, KIRC, KIRP, PAAD, PCPG, and THCA. The enrichment analysis indicated that the tumorigenesis mechanism of this gene was mainly related to "glycolysis and glucose metabolism synthesis." SLC16A1 was a promising prognostic and immunological biomarker in pan-cancer.

Identifying somatic changes in drug transporters using whole genome and transcriptome sequencing data of advanced tumors

Drug resistance is a perpetual problem in cancer therapy with many underlying mechanisms. Alterations in drug transport over the cancer cell membrane can severely alter intratumoral drug exposure, contributing to resistance. Here, we present the somatic mutational landscape of 48 ATP-binding cassette and 416 solute carrier transporter genes in a cohort (CPCT-02; NCT01855477) of 3290 patients with different types of advanced and metastasized cancer through analysis of whole genome and transcriptome sequencing. In order to identify potential stressor mechanisms, we stratified patients based on previous systemic therapies and subsequently investigated the enrichment of mutations and copy-number alterations of transporter genes. In tumors from patients pretreated with protein kinase inhibitors (PKIs), genes encoding for specific copper (SLC31A1 and SLC31A2, χ²-test adjusted p-values: 6.9e-09 and 2.5e-09) and nucleoside transporters (SLC28A2 and SLC28A3, χ²-test adjusted p-values: 3.5e-06 and 6.8e-07) were deleted significantly more frequently than in patients pretreated with chemotherapy. Moreover, we detected 16 transporters that were differentially expressed at RNA level between these treatment groups. These findings contradict mechanisms of selective pressure, as they would be expected to originate during treatment with chemotherapy rather than with PKIs. Hence, they might constitute primary drug resistance mechanisms and, therefore, warrant further study.

MicroRNA-dependent mechanisms of taxane resistance in breast cancer

Breast cancer (BC) has a leading position in the statistics of oncological morbidity and mortality among women. Taxan-based polychemotherapy regimens are an essential component of the complex therapy of the BC. However, currently used algorithms of taxan-based regimens application do not always provide with desire effect. It indicates the need to identify new prognostic markers and to develop new approaches to modify response of BC cells to standard therapeutic regimens. MicroRNAs, small RNA molecules regulating protein synthesis, are considered as promising markers and potential modulators of the BC cells sensitivity to taxanes.

The review includes a brief summary of the molecular mechanisms of action of the taxanes and the mechanism BC resistance to the process of microtubules depolymerization, provides with analysis of recent experimental and observational studies of the role of microRNAs in control of these mechanisms, and evaluates prospects for the development of new approaches to predict and to improve the cytostatic effects of taxanes through the analysis and modification of cellular microRNAs.

Metabolic Pathways in Breast Cancer Reprograming: An Insight to Non-Coding RNAs

Cancer cells reprogram their metabolisms to achieve high energetic requirements and produce precursors that facilitate uncontrolled cell proliferation. Metabolic reprograming involves not only the dysregulation in glucose-metabolizing regulatory enzymes, but also the enzymes engaging in the lipid and amino acid metabolisms. Nevertheless, the underlying regulatory mechanisms of reprograming are not fully understood. Non-coding RNAs (ncRNAs) as functional RNA molecules cannot translate into proteins, but they do play a regulatory role in gene expression. Moreover, ncRNAs have been demonstrated to be implicated in the metabolic modulations in breast cancer (BC) by regulating the metabolic-related enzymes. Here, we will focus on the regulatory involvement of ncRNAs (microRNA, circular RNA and long ncRNA) in BC metabolism, including glucose, lipid and glutamine metabolism. Investigation of this aspect may not only alter the approaches of BC diagnosis and prognosis, but may also open a new avenue in using ncRNA-based therapeutics for BC treatment by targeting different metabolic pathways.

Relationship between metabolic reprogramming and drug resistance in breast cancer

Breast cancer is the leading cause of cancer death in women. At present, chemotherapy is the main method to treat breast cancer in addition to surgery and radiotherapy, but the process of chemotherapy is often accompanied by the development of drug resistance, which leads to a reduction in drug efficacy. Furthermore, mounting evidence indicates that drug resistance is caused by dysregulated cellular metabolism, and metabolic reprogramming, including enhanced glucose metabolism, fatty acid synthesis and glutamine metabolic rates, is one of the hallmarks of cancer. Changes in metabolism have been considered one of the most important causes of resistance to treatment, and knowledge of the mechanisms involved will help in identifying potential treatment deficiencies. To improve women’s survival outcomes, it is vital to elucidate the relationship between metabolic reprogramming and drug resistance in breast cancer. This review analyzes and investigates the reprogramming of metabolism and resistance to breast cancer therapy, and the results offer promise for novel targeted and cell-based therapies.

Multifunctional profiling of triple-negative breast cancer patient-derived tumoroids for disease modeling

3D cell models derived from patient tumors are highly translational tools that can recapitulate the complex genetic and molecular compositions of solid cancers and accelerate identification of drug targets and drug testing. However, the complexity of performing assays with such models remains a hurdle for their wider adoption. In the present study, we describe methods for processing and multi-functional profiling of tumoroid samples to test compound effects using a novel flowchip system in combination with high content imaging and metabolite analysis. Tumoroids were formed from primary cells isolated from a patient-derived tumor explant, TU-BcX-4IC, that represents metaplastic breast cancer with a triple-negative breast cancer subtype. Assays were performed in a microfluidics-based device (Pu⋅MA System) that allows automated exchange of media and treatments of tumoroids in a tissue culture incubator environment. Multi-functional assay profiling was performed on tumoroids treated with anti-cancer drugs. High-content imaging was used to evaluate drug effects on cell viability and expression of E-cadherin and CD44. Lactate secretion was used to measure tumoroid metabolism as a function of time and drug concentration. Observed responses included loss of cell viability, decrease in E-cadherin expression, and increase of lactate production. Importantly, the tumoroids were sensitive to romidepsin and trametinib, while showed significantly reduced sensitivity to paclitaxel and cytarabine, consistent with the primary tumor response. These methods for multi-parametric profiling of drug effects in patient-derived tumoroids provide an in depth understanding of drug sensitivity of individual tumor types, with important implications for the future development of personalized medicine.

Triple Isozyme Lactic Acid Dehydrogenase Inhibition in Fully Viable MDA-MB-231 Cells Induces Cytostatic Effects That Are Not Reversed by Exogenous Lactic Acid

A number of aggressive human malignant tumors are characterized by an intensified glycolytic rate, over-expression of lactic acid dehydrogenase A (LDHA), and subsequent lactate accumulation, all of which contribute toward an acidic peri-cellular immunosuppressive tumor microenvironment (TME). While recent focus has been directed at how to inhibit LDHA, it is now becoming clear that multiple isozymes of LDH must be simultaneously inhibited in order to fully suppress lactic acid and halt glycolysis. In this work we explore the biochemical and genomic consequences of an applied triple LDH isozyme inhibitor (A, B, and C) (GNE-140) in MDA-MB-231 triple-negative breast cancer cells (TNBC) cells. The findings confirm that GNE-140 does in fact, fully block the production of lactic acid, which also results in a block of glucose utilization and severe impedance of the glycolytic pathway. Without a fully functional glycolytic pathway, breast cancer cells continue to thrive, sustain viability, produce ample energy, and maintain mitochondrial potential (ΔΨ_M). The only observable negative consequence of GNE-140 in this work, was the attenuation of cell division, evident in both 2D and 3D cultures and occurring in fully viable cells. Of important note, the cytostatic effects were not reversed by the addition of exogenous (+) lactic acid. While the effects of GNE-140 on the whole transcriptome were mild (12 up-regulated differential expressed genes (DEGs); 77 down-regulated DEGs) out of the 48,226 evaluated, the down-regulated DEGS collectively centered around a loss of genes related to mitosis, cell cycle, GO/G1–G1/S transition, and DNA replication. These data were also observed with digital florescence cytometry and flow cytometry, both corroborating a G0/G1 phase blockage. In conclusion, the findings in this work suggest there is an unknown element linking LDH enzyme activity to cell cycle progression, and this factor is completely independent of lactic acid. The data also establish that complete inhibition of LDH in cancer cells is not a detriment to cell viability or basic production of energy.

Contribution of miRNAs in the Pathogenesis of Breast Cancer

Breast cancer is the most frequently diagnosed cancer among females. Gene expression profiling methods have shown the deregulation of several genes in breast cancer samples and have confirmed the heterogeneous nature of breast cancer at the genomic level. microRNAs (miRNAs) are among the recently appreciated contributors in breast carcinogenic processes. These small-sized transcripts have been shown to partake in breast carcinogenesis through modulation of apoptosis, autophagy, and epithelial-mesenchymal transition. Moreover, they can confer resistance to chemotherapy. Based on the contribution of miRNAs in almost all fundamental aspects of breast carcinogenesis, therapeutic intervention with their expression might affect the course of this disorder. Moreover, the presence of miRNAs in the peripheral blood of patients potentiates these transcripts as tools for non-invasive diagnosis of breast cancer.

The Mechanism of Warburg Effect-Induced Chemoresistance in Cancer

Although chemotherapy can improve the overall survival and prognosis of cancer patients, chemoresistance remains an obstacle due to the diversity, heterogeneity, and adaptability to environmental alters in clinic. To determine more possibilities for cancer therapy, recent studies have begun to explore changes in the metabolism, especially glycolysis. The Warburg effect is a hallmark of cancer that refers to the preference of cancer cells to metabolize glucose anaerobically rather than aerobically, even under normoxia, which contributes to chemoresistance. However, the association between glycolysis and chemoresistance and molecular mechanisms of glycolysis-induced chemoresistance remains unclear. This review describes the mechanism of glycolysis-induced chemoresistance from the aspects of glycolysis process, signaling pathways, tumor microenvironment, and their interactions. The understanding of how glycolysis induces chemoresistance may provide new molecular targets and concepts for cancer therapy.

Microglia-Derived Small Extracellular Vesicles Reduce Glioma Growth by Modifying Tumor Cell Metabolism and Enhancing Glutamate Clearance through miR-124

Brain homeostasis needs continuous exchange of intercellular information among neurons, glial cells, and immune cells, namely microglial cells. Extracellular vesicles (EVs) are active players of this process. All the cells of the body, including the brain, release at least two subtypes of EVs, the medium/large EVs (m/lEVs) and small EVs (sEVs). sEVs released by microglia play an important role in brain patrolling in physio-pathological processes. One of the most common and malignant forms of brain cancer is glioblastoma. Altered intercellular communications constitute a base for the onset and the development of the disease. In this work, we used microglia-derived sEVs to assay their effects in vitro on murine glioma cells and in vivo in a glioma model on C57BL6/N mice. Our findings indicated that sEVs carry messages to cancer cells that modify glioma cell metabolism, reducing lactate, nitric oxide (NO), and glutamate (Glu) release. sEVs affect Glu homeostasis, increasing the expression of Glu transporter Glt-1 on astrocytes. We demonstrated that these effects are mediated by miR-124 contained in microglia-released sEVs. The in vivo benefit of microglia-derived sEVs results in a significantly reduced tumor mass and an increased survival of glioma-bearing mice, depending on miR-124.

lncRNA PVT1 promotes cetuximab resistance of head and neck squamous cell carcinoma cells by inhibiting miR-124-3p

BACKGROUND

Cetuximab has been widely used in the clinical treatment of head and neck squamous cell carcinoma (HNSCC). However, whether long non-coding RNA plasmacytoma variant translocation 1 (lncRNA PVT1) is correlated with cetuximab resistance remains unclear.

METHODS

Western blot and qRT-PCR were performed to quantify the levels of genes and proteins, respectively. Cell functions were measured using Cell Counting Kit-8 (CCK-8), Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and flow cytometry assays. The methylation level was tested using methylation-specific PCR (MSP).

RESULTS

PVT1 was upregulated and positively correlated with the poor prognosis of HNSCC. PVT1 overexpression markedly promoted the survival and weakened the cetuximab sensitivity of HNSCC cells, while miR-124-3p overexpression showed opposite effects. Mechanistically, the silence of PVT1 indirectly promoted miR-124-3p expression by reducing its promoter methylation. Importantly, miR-124-3p overexpression impeded the regulatory roles of PVT1 overexpression.

CONCLUSION

PVT1 decreased the sensitivity of HNSCC cells to cetuximab by enhancing methylation-mediated inhibition of miR-124-3p, which might provide a new insight for the cetuximab chemoresistance of HNSCC.

Overexpression of Cell-Surface Marker SLC16A1 Shortened Survival in Human High-Grade Gliomas

Solute carrier family 16 member 1 (SLC16A1) is a crucial transcription factor in modifying cancer progression and metastasis. However, its character in defining the clinical prognosis of human gliomas has not been illuminated. In our analysis from PREdiction of Clinical Outcomes from Genomic Profiles (PRECOG), The Cancer Genome Atlas (TCGA), and Chinese Glioma Genome Atlas (CGGA), we found that SLC16A1 mRNA expression level was significantly increased in high-grade gliomas in contrast to low-grade gliomas and non-tumor controls (P < 0.05). Kaplan-Meier analysis of four independent cohort studies from the Gene Expression Omnibus (GEO) profile, TCGA, and CGGA which consistently presented patients with high SLC16A1 mRNA expression displayed poor overall survival in high-grade glioma patients (P < 0.05 by log-rank test). Based on the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING), the protein-protein interaction analysis of SLC16A1-regulated oncogenesis showed SLC16A1 as a potential hub protein. Immunohistochemical staining exhibited that SLC16A1 protein overexpressed in high-grade gliomas compared with low-grade clinical glioma samples. All these findings suggest that SLC16A1 expression has a positive correlation with WHO pathological grading and poor survival. SLC16A1 might be a potential biomarker of prognosis in human gliomas.

A paclitaxel and microRNA-124 coloaded stepped cleavable nanosystem against triple negative breast cancer

Background

Triple negative breast cancer (TNBC) is one of the most biologically aggressive breast cancers and lacks effective treatment options, resulting in a poor prognosis. Therefore, studies aiming to explore new therapeutic strategies for advanced TNBC are urgently needed. According to recent studies, microRNA-124 (miR124) not only inhibits tumour growth but also increases the sensitivity of TNBC to paclitaxel (PTX), suggesting that a platform combining PTX and miR124 may be an advanced solution for TNBC.

Results

Herein, we constructed a stepped cleavable calcium phosphate composite lipid nanosystem (CaP/LNS) to codeliver PTX and miR124 (PTX/miR124-NP). PTX/miR124-NP exhibited superior tumor microenvironment responsive ability, in which the surface PEG layer was shed in the mildly acidic environment of tumor tissues and exposed oligomeric hyaluronic acid (o-HA) facilitated the cellular uptake of CaP/LNS by targeting the CD44 receptor on the surface of tumor cells. Inside tumour cells, o-HA detached from CaP/LNS due to the reduction of disulfide bonds by glutathione (GSH) and inhibited tumour metastasis. Then, PTX and miR124 were sequentially released from CaP/LNS and exerted synergistic antitumour effects by reversing the Epithelial-Mesenchymal Transition (EMT) process in MDA-MB-231 cells. Moreover, PTX/miR124-NP showed significant antitumour efficiency and excellent safety in mice bearing MDA-MB-231 tumours.

Conclusion

Based on these results, the codelivery of PTX and miR124 by the CaP/LNS nanosystem might be a promising therapeutic strategy for TNBC.

A Compressive Review about Taxol®: History and Future Challenges

Taxol^®, which is also known as paclitaxel, is a chemotherapeutic agent widely used to treat different cancers. Since the discovery of its antitumoral activity, Taxol^® has been used to treat over one million patients, making it one of the most widely employed antitumoral drugs. Taxol^® was the first microtubule targeting agent described in the literature, with its main mechanism of action consisting of the disruption of microtubule dynamics, thus inducing mitotic arrest and cell death. However, secondary mechanisms for achieving apoptosis have also been demonstrated. Despite its wide use, Taxol^® has certain disadvantages. The main challenges facing Taxol^® are the need to find an environmentally sustainable production method based on the use of microorganisms, increase its bioavailability without exerting adverse effects on the health of patients and minimize the resistance presented by a high percentage of cells treated with paclitaxel. This review details, in a succinct manner, the main aspects of this important drug, from its discovery to the present day. We highlight the main challenges that must be faced in the coming years, in order to increase the effectiveness of Taxol^® as an anticancer agent.

Predicting and Overcoming Taxane Chemoresistance

Taxanes are microtubule-targeting drugs used as cytotoxic chemotherapy to treat most solid tumors. The development of resistance to taxanes is a major cause of therapeutic failure and overcoming chemoresistance remains an important challenge to improve patient's outcome. Extensive efforts have been made recently to identify predictive biomarkers to select populations of patients who will benefit from taxane-based chemotherapy and avoid inefficient treatment of patients with innate resistance. This, together with the discovery of new mechanisms of resistance that include metabolic reprogramming and dialogue between tumor and its microenvironment, pave the way to a new era of personalized medicine. In this review, we recapitulate recent insights into taxane resistance and present promising emerging strategies to overcome chemoresistance in the future.

Paclitaxel exposure downregulates miR-522 expression and its downregulation induces paclitaxel resistance in ovarian cancer cells

Paclitaxel resistance is a critical challenge in ovarian cancer treatment. This study aimed to identify microRNAs (miRNAs) that modulate paclitaxel resistance for use as potential therapeutic targets in such settings. Paclitaxel-resistant cell lines were established using two ovarian cancer cell lines: SKOV3ip1 and HeyA8. The evaluation of miRNA polymerase chain reaction (PCR) arrays indicated that the expression of miR-522-3p was downregulated in paclitaxel-resistant cells. The restoration of miR-522-3p sensitized the resistant cells to paclitaxel, and its downregulation desensitized the parental cells. Using PCR arrays, we focused on E2F2, with the luciferase reporter assay revealing that it was a direct target for miR-522-3p. The paclitaxel-resistant cells showed stronger E2F2 expression than the parental cells, while E2F2 inhibition sensitized the resistant cells to paclitaxel. Forced E2F2 expression in the parental cells led to the acquisition of paclitaxel resistance, while miR-522-3p inhibited E2F2 expression and was associated with retinoblastoma protein phosphorylation attenuation, which resulted in G0/G1 arrest. The effects of miR-522-3p and E2F2 in ovarian cancer were examined using public databases, revealing that low miR-522-3p expression and high E2F2 expression were associated with significantly poorer overall survival. In conclusion, miR-522-3p attenuated the degree of paclitaxel resistance in vitro through the downregulation of E2F2; miR-522-3p supplementation may be a therapeutic target for paclitaxel-resistant ovarian cancer.

AKT2 drives cancer progression and is negatively modulated by miR-124 in human lung adenocarcinoma

BACKGROUND

AKT2 is highly expressed in many human cancers, including non-small cell lung cancer (NSCLC). Accumulating evidence has also revealed that AKT2 can promote NSCLC cell proliferation and metastasis. However, the involved mechanism remains unclear. Herein, our study mainly explored the function of AKT2 during cancer progression and uncovered a new post-transcriptional mechanism of AKT2 expression in lung adenocarcinoma (LUAD).

METHODS

Quantitative real-time (qRT-PCR), western blot and immunohistochemistry (IHC) assays were performed to detect the expression of AKT2 and other proteins. Cell counting kit-8 (CCK-8), colony formation and EdU assays were performed to assess cell proliferation. Flow cytometry analysis was used to detect changes in the cell cycle and apoptosis. Transwell assays were used to evaluate cell migration and invasion. Additionally, a luciferase reporter assay and western blotting were employed to assess miR-124 targeting of AKT2. Xenograft mouse model was used to observe the role of miR-124/AKT2 axis on the occurrence and development of LUAD.

RESULTS

We showed that AKT2 was highly expressed in NSCLC tissues and closely related to the poor prognosis of LUAD patients. Moreover, AKT2 affected LUAD cell proliferation, migration and invasion by regulating the cell cycle and promoting the occurrence of epithelial-mesenchymal transition (EMT) and the expression of matrix metalloproteinases (MMPs). In addition, we demonstrated that miR-124 overexpression downregulated AKT2 expression by binding to the 3'-untranslated region (3'- UTR) of AKT2 and thus inhibited the occurrence and development of LUAD in vivo and in vitro.

CONCLUSIONS

Our results suggest that miR-124 overexpression can negatively regulate AKT2 and thus inhibit the progression of LUAD. Therefore, the miR-124/AKT2 axis may serve as a potential target for novel therapies for LUAD.

Low Expression of miR-20a-5p Predicts Benefit to Bevacizumab in Metastatic Breast Cancer Patients Treated within the TANIA Phase III Trial

Background: In metastatic breast cancer (MBC) patients, no biomarker predicting benefit to a bevacizumab-containing therapy has been established yet. MicroRNAs (miRNAs) are involved in angiogenesis and treatment resistance and therefore could be of predictive value. Methods: Profiling of 754 miRNAs was performed in tumor samples of 58 MBC patients treated with a bevacizumab-containing first-line regimen (learning set). Based on progression-free survival (PFS), patients were divided into responders (R) and non-responders (NR). Differentially expressed miRNAs between R and NR were analyzed in a cohort of 57 patients treated with first-line chemotherapy without bevacizumab (control set), to exclude miRNAs providing prognostic information. MiRNA candidates significantly associated with PFS in multivariate analysis were further validated in tumor samples of 203 patients treated within the phase III trial TANIA randomizing between chemotherapy either alone or with bevacizumab after progression on first-line bevacizumab. Results: Low expression of miR-20a-5p (multivariate p = 0.035) and miR-21-5p (multivariate p = 0.004) were significantly associated with longer PFS in the learning set, but not in the control set. In samples from the TANIA trial, low expression of miR-20a-5p was also significantly associated with longer PFS (hazard ration (HR) 0.60; 95%-CI 0.37–0.89; p = 0.012) and longer overall survival (OS; HR 0.54; 95%-CI 0.32–0.83; p = 0.007) in the bevacizumab arm but not in the chemotherapy-only arm (PFS: HR 0.73, p = 0.119; OS: HR 1.01; p = 0.964). For miR-21-5p no significant association with PFS or OS in both treatment arms was observed. Conclusion: MiR-20a-5p expression in breast cancer tissue was predictive for a greater benefit from bevacizumab-containing therapy in two independent cohorts.

Monocarboxylate Transporter 1 (MCT1) in Liver Pathology

Membrane monocarboxylate transporter 1 (SLC16A1/MCT1) plays an important role in hepatocyte homeostasis, as well as drug handling. However, there is no available information about the impact of liver pathology on the transporter levels and function. The study was aimed to quantify SLC16A1 mRNA (qRT-PCR) and MCT1 protein abundance (liquid chromatography–tandem mass spectrometry (LC¬¬–MS/MS)) in the livers of patients diagnosed, according to the standard clinical criteria, with hepatitis C, primary biliary cirrhosis, primary sclerosing hepatitis, alcoholic liver disease (ALD), and autoimmune hepatitis. The stage of liver dysfunction was classified according to Child–Pugh score. Downregulation of SLC16A1/MCT1 levels was observed in all liver pathology states, significantly for ALD. The progression of liver dysfunction, from Child–Pugh class A to C, involved the gradual decline in SLC16A1 mRNA and MCT1 protein abundance, reaching a clinically significant decrease in class C livers. Reduced levels of MCT1 were associated with significant intracellular lactate accumulation. The MCT1 transcript and protein did not demonstrate significant correlations regardless of the liver pathology analyzed, as well as the disease stage, suggesting posttranscriptional regulation, and several microRNAs were found as potential regulators of MCT1 abundance. MCT1 membrane immunolocalization without cytoplasmic retention was observed in all studied liver pathologies. Overall, the study demonstrates that SLC16A1/MCT1 is involved in liver pathology, especially in ALD.

Targeting Cancer Metabolism to Resensitize Chemotherapy: Potential Development of Cancer Chemosensitizers from Traditional Chinese Medicines

Cancer is a common and complex disease with high incidence and mortality rates, which causes a severe public health problem worldwide. As one of the standard therapeutic approaches for cancer therapy, the prognosis and outcome of chemotherapy are still far from satisfactory due to the severe side effects and increasingly acquired resistance. The development of novel and effective treatment strategies to overcome chemoresistance is urgent for cancer therapy. Metabolic reprogramming is one of the hallmarks of cancer. Cancer cells could rewire metabolic pathways to facilitate tumorigenesis, tumor progression, and metastasis, as well as chemoresistance. The metabolic reprogramming may serve as a promising therapeutic strategy and rekindle the research enthusiasm for overcoming chemoresistance. This review focuses on emerging mechanisms underlying rewired metabolic pathways for cancer chemoresistance in terms of glucose and energy, lipid, amino acid, and nucleotide metabolisms, as well as other related metabolisms. In particular, we highlight the potential of traditional Chinese medicine as a chemosensitizer for cancer chemotherapy from the metabolic perspective. The perspectives of metabolic targeting to chemoresistance are also discussed. In conclusion, the elucidation of the underlying metabolic reprogramming mechanisms by which cancer cells develop chemoresistance and traditional Chinese medicines resensitize chemotherapy would provide us a new insight into developing promising therapeutics and scientific evidence for clinical use of traditional Chinese medicine as a chemosensitizer for cancer therapy.

Nanotechnology, in silico and endocrine-based strategy for delivering paclitaxel and miRNA: Prospects for the therapeutic management of breast cancer

Breast cancer is one of the most prevalent and reoccurring cancers and the second most common reason of death in women. Despite advancements in therapeutic strategies for breast cancer, early tumor recurrence and metastasis in patients indicate resistance to chemotherapeutic medicines, such as paclitaxel due to the abnormal expression of ER and EGF2 in breast cancer cells. Therefore, the development of alternatives to paclitaxel is urgently needed to overcome challenges involving drug resistance. An increasing number of studies has revealed miRNAs as novel natural alternative substances that play a crucial role in regulating several physiological processes and have a close, adverse association with several diseases, including breast cancer. Due to the therapeutic potential of miRNA and paclitaxel in cancer research, the current review focuses on the differential roles of various miRNAs in breast cancer development and treatment. miRNA delivery to a specific target site, the development of paclitaxel and miRNA formulations, and nanotechnological strategies for the delivery of nanopaclitaxel in the management of breast cancer are discussed. These strategies involve improving the cellular uptake and bioavailability and reducing the toxicity of free paclitaxel to achieve accumulation tumor site. Furthermore, a molecular docking study was performed to ascertain the enhanced anticancer activity of the nanoformulation of ANG1005 and Abraxane. An in silico analysis revealed that ANG1005 and Abraxane nanoformulations have superior and significantly enhanced interactions with the proteins α-tubulin and Bcl-2. Therefore, ANG1005 and Abraxane may be more suitable in the therapeutic management of breast cancer than the existing free paclitaxel. miRNAs can revert abnormal gene expression to normalcy; since miRNAs serve as tumor suppressors. Therefore, restoration of particular miRNAs levels as a replacement therapy may be an effective endocrine potential strategy for treating ER positive/ negative breast cancers.