MTFR2-dependent mitochondrial fission promotes HCC progression

Identification of molecular subtypes and a prognostic risk model based on mitochondrial dynamic related genes in clear cell renal cell carcinoma

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) represents the most prevalent histological subtype and primary contributor to unfavorable prognosis in renal cancer. While mitochondrial dynamics serve as a critical quality control mechanism linked to tumor malignancy, their clinical significance and specific mechanisms in ccRCC remain poorly understood.

METHODS

Consnsuclusterplus was used to consensus clustering and molecular subtype screening, Kaplan-Meier analysis was used to analyze survival in different subtypes. PINK1 expression was detected by westernblot, and CCK8 is used to detect cell activity. Immunofluorescence staining of LC3 for evaluating mitochondrial autophagy levels.

RESULTS

In this study, we classified 534 ccRCC samples, identified from the UCSC XENA database, into A and B clusters based on 42 mitochondrial dynamic related genes. Cluster A demonstrated superior survival outcomes compared to cluster B. Subsequent analysis revealed significant inter-cluster differences in gene expression profiles, mutational spectra, and immune infiltration patterns. We established a mitochondrial dynamics-related prognostic model incorporating PINK1, NIPSNAP1, and MTFR2, with mitophagy-associated genes represented by PINK1 showing particular prognostic significance in ccRCC. Gene Ontology (GO) analysis indicated significant enrichment of mitophagy pathways in cluster A. Functional investigations demonstrated that PINK1-overexpressing cells exhibited increased sensitivity to sunitinib (lower IC50 values), whereas PINK1 knockdown conferred therapeutic resistance. Western blot and immunofluorescence analyses confirmed elevated mitophagy levels in PINK1-overexpressing cells under sunitinib treatment, contrasting with diminished mitophagy in PINK1-deficient cells.

CONCLUSIONS

Our findings advance the understanding of mitochondrial dynamics in ccRCC progression, demonstrating that PINK1-mediated enhancement of mitophagy critically potentiates the anti-tumor effects of sunitinib in ccRCC.

Predictive biomarkers in the era of immunotherapy for gastric cancer: current achievements and future perspectives

Gastric cancer (GC) is one of the primary contributors to cancer-related mortality on a global scale. It holds a position within the top five most prevalent malignancies both in terms of occurrence and fatality rates. Immunotherapy, as a breakthrough cancer treatment, brings new hope for GC patients. Various biomarkers, such as the expression of programmed death ligand-1 (PD-L1), the microsatellite instability (MSI) status, tumor mutational burden (TMB), and Epstein-Barr virus (EBV) infection, demonstrate potential to predict the effectiveness of immunotherapy in treating GC. Nevertheless, each biomarker has its own limitations, which leads to a significant portion of patients continue to be unresponsive to immunotherapy. With the understanding of the tumor immune microenvironment (TIME), genome sequencing technology, and recent advances in molecular biology, new molecular markers, such as POLE/POLD1mutations, circulating tumor DNA, intestinal flora, lymphocyte activation gene 3 (LAG-3), and lipid metabolism have emerged. This review aims to consolidate clinical evidence to offer a thorough comprehension of the existing and emerging biomarkers. We discuss the mechanisms, prospects of application, and limitations of each biomarker. We anticipate that this review will open avenues for fresh perspectives in the investigation of GC immunotherapy biomarkers and promote the precise choice of treatment modalities for gastric cancer patients, thereby advancing precision immuno-oncology endeavors.

MTFR1 phosphorylation-activated adaptive mitochondrial fusion is essential for colon cancer cell survival during glucose deprivation

BACKGROUND

Mitochondrial dynamics are essential for maintaining cellular function under metabolic stress. However, their role in colon cancer's response to glucose deprivation remains poorly understood.

METHODS

The role of the mitochondrial protein MTFR1 in colon cancer proliferation was evaluated using CCK-8 and colony formation assays. Mass spectrometry identified MTFR1-interacting proteins and phosphorylation sites. Mitochondrial morphology was examined with Mitotracker staining, and mitochondrial function was evaluated using MitoSOX, JC-1 staining, and the Seahorse cell mitochondrial stress test.

RESULTS

We observed that MTFR1 is highly expressed in colon cancer cells and interacts with NEK1 under glucose deprivation. This interaction induces phosphorylation of MTFR1 at serine 119, which promotes mitochondrial fusion and supports mitochondrial function. Consequently, enhanced oxidative phosphorylation improves cellular tolerance to glucose deprivation.

CONCLUSIONS

Our findings highlight the importance of MTFR1 in modulating mitochondrial dynamics and its potential impact on colon cancer cell survival under metabolic stress. These results suggest that MTFR1 serine 119 could be a key regulator of colon cancer cell metabolism and a potential therapeutic target for enhancing cancer cell response to metabolic challenges.

Comprehensive analysis of bioinformatics identification TST, SQOR and NRDC is mitochondria-related biomarkers of ischemic cerebral apoplexy

Mitochondria are an important organelle affecting the occurrence and development of ischemic stroke (IS). Although the role of mitochondria in IS has been paid attention to, the relevant biomarkers have not been identified, and the targeted treatment is still lacking. To further solve these problems, in this study, we combined and standardized GSE16561 and GSE58294 datasets in the GEO database as the test set, and GSE22255 as the training set. The mitochondria-related gene set was obtained from MitoCarta3.0 for study. R language was used to screen differentially expressed genes (DEGs), and weighted gene co-expression network analysis (WGCNA) was used to obtain the intersection genes. KEGG pathway enrichment and gene ontology (GO) analysis were performed. LASSO and Logistic methods were used to determine the diagnostic markers of mitochondrial-related IS. The correlation between it and the main immune cells and immune-related factors was analysed. The ROC curve was used to determine the diagnostic efficacy. The protein co-expression network, transcription factor, and miRNA prediction, and drug prediction by cMAP were performed against these markers. Molecular docking tested the binding energy. Transmission electron microscopy was used to observe the structure and morphology of mitochondria in cerebral microvascular endothelial cells of MCAO/R rats. Biochemical kits were used to detect the levels of MDA and SOD in blood and tissues. Elisa was used to detect the changes of the above targets in blood and tissues. In this study, a total of 38 intersection genes were obtained, and a diagnostic model composed of 3 genes (TST, SQOR, NRDC) was further established. KEGG and GO analysis showed that these genes were highly related to immunity and were involved in the immune activities related to neutrophils, CD4+T cells, CD8+T cells, and macrophages. In addition, a total of 42 proteins, 601 transcription factors, and 99 miRNAs related to TST, SQOR, and NRDC were predicted, and the interaction map was constructed. cMAP predicted 5 potential small molecule drugs and molecular docking suggested that W.13 had the best binding energy. In MCAO/R rats, the mitochondria in BMECs were severely damaged and fragmented, accompanied by a decrease in SOD activity and an increase in MDA level. In addition, the levels of TST and SQOR in blood and tissues were increased, and the levels of NRDC were decreased. Our study provides new insights into further understanding of IS from a mitochondrial perspective.

MTFR2 promotes endometrial carcinoma cell proliferation and growth via the miR-132-3p/PI3K/Akt signaling pathway

Objective

Understanding the mechanisms underlying endometrial cancer progression is crucial for the development of effective targeted therapies. In this study, we investigated the role of MTFR2 in endometrial cancer cell.

Methods

The expression of MTFR2 in endometrial cancer was analyzed using The Cancer Genome Atlas (TCGA) dataset and detected in endometrial cancer tissues and cells, respectively. Gain-of-function and loss-of-function approaches were utilized to investigate the impact of MTFR2 on endometrial cancer cell proliferation and tumorigenesis in both in vitro and in vivo settings. Computational tools were employed to predict microRNAs (miRNAs) that potentially regulate MTFR2, and these predictions were experimentally validated.

Results

The expression of MTFR2 is enhanced in endometrial carcinoma, and it is positively correlated with the poor prognosis of patients. Functional studies show that MTFR2 promoted the proliferation, migration and invasion of endometrial cancer cells. Bioinformatics analysis and luciferase assays identified that MTFR2 is a potential target of miR-132-3p, and transfection with miR-132-3p mimics attenuated the MTFR2-induced activation of the PI3K/Akt pathway.

Conclusion

Our findings highlight the critical role of MTFR2 in promoting endometrial cancer cell proliferation and growth through the miR-132-3p/PI3K/Akt signaling pathway. Targeting this signaling axis may offer potential therapeutic strategies for endometrial cancer treatment.

Depleting chemoresponsive mitochondrial fission mediator DRP1 does not mitigate sarcoma resistance

Specific patterns of mitochondrial dynamics have been repeatedly reported to promote drug resistance in cancer. However, whether targeting mitochondrial fission- and fusion-related proteins could be leveraged to combat multidrug-resistant pediatric sarcomas is poorly understood. Here, we demonstrated that the expression and activation of the mitochondrial fission mediator DRP1 are affected by chemotherapy exposure in common pediatric sarcomas, namely, rhabdomyosarcoma and osteosarcoma. Unexpectedly, decreasing DRP1 activity through stable DRP1 knockdown neither attenuated sarcoma drug resistance nor affected growth rate or mitochondrial network morphology. The minimal impact on sarcoma cell physiology, along with the up-regulation of fission adaptor proteins (MFF and FIS1) detected in rhabdomyosarcoma cells, suggests an alternative DRP1-independent mitochondrial fission mechanism that may efficiently compensate for the lack of DRP1 activity. By exploring the upstream mitophagy and mitochondrial fission regulator, AMPKα1, we found that markedly reduced AMPKα1 levels are sufficient to maintain AMPK signaling capacity without affecting chemosensitivity. Collectively, our findings challenge the direct involvement of DRP1 in pediatric sarcoma drug resistance and highlight the complexity of yet-to-be-characterized noncanonical regulators of mitochondrial dynamics.

Mitochondria's Role in the Maintenance of Cancer Stem Cells in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the predominant form of liver cancer and is recognized as a major contributor to cancer-related mortality worldwide. Cancer stem cells (CSCs) are a tiny group of cancer cells that possess a significant ability to regenerate themselves, form tumors, and undergo differentiation. CSCs have a pivotal role in the initiation, spread, recurrence, and resistance to treatment of cancer. As a result, they are very susceptible to being targeted for therapeutic intervention. The potential to cure HCC may be achieved by efficiently targeting drugs that eradicate cancer stem cells. Mitochondria have a crucial function in granting drug resistance to cancer stem cells by means of mitochondrial metabolism, biogenesis, and dynamics. Dysfunction in mitochondrial metabolic processes, such as mitochondrial oxidative phosphorylation (OXPHOS), calcium signaling, and reactive oxygen species (ROS) generation, contributes to the initiation and progression of human malignancies, including HCC. ROS have both beneficial and detrimental effects depending on their concentration. Consequently, ROS have become a prominent subject in the study of the fundamental mechanisms of HCC. Furthermore, an imbalance in the process of creating new mitochondria is a characteristic feature of CSCs, and an increase in mitochondrial biogenesis is associated with the heightened resistance observed in CSCs. This article provides a detailed examination of the involvement of mitochondria in the preservation of CSCs, as well as the spread of HCC. A deeper understanding of how mitochondria participate in tumorigenesis and drug resistance could result in the discovery of novel cancer treatments.

MTFR2 accelerates hepatocellular carcinoma mediated by metabolic reprogramming via the Akt signaling pathway

Metabolic reprogramming has recently been identified as a hallmark of malignancies. The shift from oxidative phosphorylation to glycolysis in hepatocellular carcinoma (HCC) meets the demands of rapid cell growth and provides a microenvironment for tumor progression. This study sought to uncover the function and mechanism of MTFR2 in the metabolic reprogramming of HCC. Elevated MTFR2 expression was associated with poor patient prognosis. Downregulation of MTFR2 blocked malignant behaviors, epithelial-to-mesenchymal transition (EMT), and glycolysis in HCC cells. Nuclear transcription factor Y subunit gamma (NFYC) was also associated with poor patient prognosis, and NFYC bound to the promoter of MTFR2 to activate transcription and promote Akt signaling. The repressive effects of NFYC knockdown on EMT and glycolysis in HCC cells were compromised by MTFR2 overexpression, elicited through the activation of the Akt signaling. Knockdown of NFYC slowed the growth and intrahepatic metastasis in vivo, which was reversed by MTFR2 overexpression. In conclusion, our work shows that activation of MTFR2 by the transcription factor NFYC promotes Akt signaling, thereby potentiating metabolic reprogramming in HCC development. Targeting the NFYC/MTFR2/Akt axis may represent a therapeutic strategy for HCC.

Comprehensive analysis of cuproptosis-related genes involved in prognosis and tumor microenvironment infiltration of colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is a common malignancy, with high incidence and high mortality rates. Cuproptosis, a novel form of copper-induced programmed cell death, contributes to tumor progression. However, whether cuproptosis-related genes (CRGs) play a role in CRC remains unclear. This study aims to elucidate the role of CRGs in CRC development, patient prognosis, and immune response.

METHODS

We performed bioinformatics analysis of the differential expression of CRGs between CRC and normal tissues. Least absolute shrinkage and selection operator (LASSO), and univariate and multivariate Cox analyses were employed to identify risk factors, which were used to construct a risk score model. Patients with CRC were categorized into high- and low-risk groups based on their median risk scores. Receiver operating characteristic curve analysis was used to verify the predictive accuracy of the risk model. A nomogram was developed for CRC through univariate and multivariate Cox regression analyses. The chemotherapeutic drug sensitivity was compared between patients with high and low CDKN2A/DLAT expression using the Wilcoxon rank-sum test. Spearman's correlation and TISIDB database analyses were conducted to determine relationships between CDKN2A or DLAT and immune cell infiltration.

RESULTS

Eight of ten identified CRGs exhibited significant differential expression between CRC and normal tissues. Among the eight significant differential expression CRGs, CDKN2A and DLAT were identified as independent risk factors for predicting overall survival (OS) in CRC. Patients with CRC in the low-risk group had longer OS than those in the high-risk group. The risk score model had good predictive accuracy for OS. Based on CDKN2A, DLAT and some clinical characteristics, a prognostic nomogram was developed to predict OS for CRC patients and showed good predictive ability. CDKN2A and DLAT expressions were significantly associated with chemotherapeutic drug sensitivity and immune cell infiltration in CRC, and the molecular subtypes and immune subtypes differed between CDKN2A and DLAT.

CONCLUSIONS

Our research revealed the prognostic value of CRGs, particularly CDKN2A and DLAT, in CRC and demonstrated the relationship between CDKN2A/DLAT and immune infiltration in CRC, thereby contributing to the outcome evaluation of patients with CRC and identifying novel targets for CRC immunotherapy.

B-cell-specific signatures reveal novel immunophenotyping and therapeutic targets for hepatocellular carcinoma

BACKGROUND

Immunotherapy presents both promises and challenges in treating hepatocellular carcinoma (HCC) due to its complex immunological microenvironment. The role of B cells, a key part of the immune system, remains uncertain in HCC.

AIM

To identify B-cell-specific signatures and reveal novel immunophenotyping and therapeutic targets for HCC.

METHODS

Using the Tumor Immune Single-cell Hub 2 database, we identified B-cell-related genes (BRGs) in HCC. Gene enrichment analysis was performed to explore the possible collaboration between B cells and T cells in HCC. We conducted univariate Cox regression analysis using The Cancer Genome Atlas liver HCC collection dataset to find BRGs linked to HCC prognosis. Subsequently, least absolute shrinkage and selection operator regression was utilized to develop a prognostic model with 11 BRGs. The model was validated using the International Cancer Genome Consortium dataset and GSE76427.

RESULTS

The risk score derived from the prognostic model emerged as an independent prognostic factor for HCC. Analysis of the immune microenvironment and cell infiltration revealed the immune status of various risk groups, supporting the cooperation of B and T cells in suppressing HCC. The BRGs model identified new molecular subtypes of HCC, each with distinct immune characteristics. Drug sensitivity analysis identified targeted drugs effective for each HCC subtype, enabling precision therapy and guiding clinical decisions.

CONCLUSION

We clarified the role of B cells in HCC and propose that the BRGs model offers promising targets for personalized immunotherapy.

A new perspective on liver diseases: Focusing on the mitochondria-associated endoplasmic reticulum membranes

The pathogenesis of liver diseases is multifaceted and intricate, posing a persistent global public health challenge with limited therapeutic options. Therefore, further research into liver diseases is imperative for better comprehension and advancement in treatment strategies. Numerous studies have confirmed the endoplasmic reticulum (ER) and mitochondria as key organelles driving liver diseases. Notably, the mitochondrial-associated ER membranes (MAMs) establish a physical and functional connection between the ER and mitochondria, highlighting the importance of inter-organelle communication in maintaining their functional homeostasis. This review delves into the intricate architecture and regulative mechanism of the integrated MAM that facilitate the physiological transfer of signals and substances between organelles. Additionally, we also provide a detailed overview regarding the varied pathogenic roles of malfunctioning MAM in liver diseases, focusing on its involvement in the progression of ER stress and mitochondrial dysfunction, the regulation of mitochondrial dynamics and Ca2+ transfer, as well as the disruption of lipid and glucose homeostasis. Furthermore, the current challenges and prospects associated with MAM in liver disease research are thoroughly discussed. In conclusion, elucidating the specific structure and function of MAM in different liver diseases may pave the way for novel therapeutic strategies.

Adipose Stem Cells and Their Interplay with Cancer Cells and Mitochondrial Reservoir: A New Promising Target

Adipose-derived stem cells (ASCs) significantly influence tumor progression within the tumor microenvironment (TME). This review examines the pro-tumorigenic roles of ASCs, focusing on paracrine signaling, direct cell-cell interactions, and immunomodulation. ASC-mediated mitochondrial transfer through tunneling nanotubes (TNTs) and gap junctions (GJs) plays a significant role in enhancing cancer cell survival and metabolism. Cancer cells with dysfunctional mitochondria acquire mitochondria from ASCs to meet their metabolic needs and thrive in the TME. Targeting mitochondrial transfer, modulating ASC function, and influencing metabolic pathways are potential therapeutic strategies. However, challenges like TME complexity, specificity, safety concerns, and resistance mechanisms must be addressed. Disrupting the ASC-cancer cell-mitochondria axis offers a promising approach to cancer therapy.

Inhibiting Pink1/Parkin-mediated mitophagy enhances the anticancer effects of quercetin in hepatocellular carcinomaf

Quercetin, a naturally occurring flavonoid, has been investigated for its potential anti-cancer effects in various types of cancer, including hepatocellular carcinoma (HCC). However, its suppressing effect on reactive oxygen species (ROS) production might limited its anti-cancer effects. In this study, we aimed to explore the interplay among quercetin, mitochondrial dynamics and mitophagy and whether mitophagy-inhibition synergistically enhances the anti-tumor effects of quercetin. Huh7 and Hep3B cells were utilized for in vitro and in vivo studies. Results showed that quercetin treatment significantly increased the expression of mitochondrial fusion genes (MFN1 and MFN2) and decreased the expression of fission genes (DRP1 and FIS1) in Huh7 and Hep3B cells, leading to a more fused and elongated mitochondrial network. Quercetin upregulated the expression of key mitophagy regulators, PINK1 and PARK2, and enhanced the colocalization of mitochondria with lysosomes, indicating increased mitophagy. Knockdown of PINK1, PARK2, or SIRT1 attenuated quercetin-induced mitophagy and reduction of intracellular ROS levels. Quercetin treatment upregulates SIRT1 expression, which subsequently enhances PINK1 and PARK2 expression in Huh7 and Hep3B cells. In vivo experiments using Hep3B xenograft models revealed that the combination of quercetin with the mitophagy inhibitor hydroxychloroquine or SIRT1 knockdown significantly enhanced the anticancer effects of quercetin, as evidenced by reduced tumor size and weight, increased necrosis and apoptosis, and decreased proliferation in tumor tissues. These findings suggest that quercetin-induced mitochondrial fusion and Pink1/Parkin-dependent mitophagy may negatively influence its anti-cancer effects in HCC. Targeting mitophagy may enhance the therapeutic potential of quercetin in HCC treatment.