Overexpressed VDAC1 in breast cancer as a novel prognostic biomarker and correlates with immune infiltrates

Single‑cell RNA‑seq necroptosis‑related genes predict the prognosis of breast cancer and affect the differentiation of CD4+ T cells in tumor immune microenvironment

Breast cancer (BC) is one of the most prevalent types of malignancy and a major cause of cancer-related death. The purpose of the present study was to identify prognostic models of necroptosis-related genes (NRGs) in BC at the single-cell RNA-sequencing level and reveal the role of NRGs in tumour immune microenvironment (TIME). A risk model was constructed based on Cox regression and LASSO methods. Next, high-scoring cell populations were searched through AUCell scores, and cell subtypes were then analyzed by pseudotime analysis. Finally, the expression level of the model genes was verified by reverse transcription-quantitative (RT-qPCR). A new prognostic model was constructed and validated based on five NRGs (BCL2, BIRC3, AIFM1, IFNG and VDAC1), which could effectively predict the prognosis of patients with BC. NRGs were found to be highly active in CD4+ T cells and differentially expressed in their developmental trajectories. Finally, the RT-qPCR results showed that most of the model genes were significantly overexpressed in MDA-MB-231 and MCF-7 cells (P<0.05). In conclusion, an NRG signature with excellent predictive properties in prognosis and TIME was successfully established. Moreover, NRGs were involved in the differentiation and development of CD4+ T cells in TIME. These findings provide potential therapeutic strategies for BC.

VDAC1-interacting molecules promote cell death in cancer organoids through mitochondrial-dependent metabolic interference

The voltage-dependent anion-selective channel isoform 1 (VDAC1) is a pivotal component in cellular metabolism and apoptosis with a prominent role in many cancer types, offering a unique therapeutic intervention point. Through an in-silico-to-in-vitro approach we identified a set of VA molecules (VDAC Antagonists) that selectively bind to VDAC1 and display specificity toward cancer cells. Biochemical characterization showed that VA molecules can directly interact with VDAC1 with micromolar affinity by competing with the endogenous ligand NADH for a partially shared binding site. NADH displacement results in mitochondrial distress and reduced cell proliferation, especially when compared to non-cancerous cells. Experiments performed on organoids derived from intrahepatic cholangiocarcinoma patients demonstrated a dose-dependent reduction in cell viability upon treatment with VA molecules with lower impact on healthy cells than conventional treatments like gemcitabine. VA molecules are chemical entities representing promising candidates for further optimization and development as cancer therapy strategies through precise metabolic interventions.

Systematic investigation of chemo-immunotherapy synergism to shift anti-PD-1 resistance in cancer

Chemo-immunotherapy combinations have been regarded as one of the most practical ways to improve immunotherapy response in cancer patients. In this study, we integrate the transcriptomics data from anti-PD-1-treated tumors and compound-treated cancer cell lines to systematically screen for chemo-immunotherapy synergisms in silico. Through analyzing anti-PD-1 induced expression changes in patient tumors, we develop a shift ability score to measure if a chemotherapy or a small molecule inhibitor treatment can shift anti-PD-1 resistance in tumor cells. By applying shift ability analysis to 41,321 compounds and 16,853 shRNA treated cancer cell lines transcriptomic data, we characterize the landscape of chemo-immunotherapy synergism and experimentally validated a mitochondrial RNA-dependent mechanism for drug-induced immune activation in tumor. Our study represents an effort to mechanistically characterize chemo-immunotherapy synergism and will facilitate future pre-clinical and clinical studies.

HER2-positive is an independent indicator for predicting pathological complete response to neoadjuvant therapy and Ki67-changed after neoadjuvant chemotherapy predicts favorable prognosis in Chinese women with locally advanced breast cancer

The growing body of evidence suggests that breast cancer (BC) who achieve pathological complete response (pCR) after neoadjuvant chemotherapy (NAC) may experience a more favorable prognosis. The objective of this study is to investigate the correlation between clinicopathologic parameters of locally advanced breast cancer (LABC) patients and the outcomes of NAC, with the aim of identifying predictive indicators for pCR. Additionally, we seek to examine the conversion of IHC markers in pCR patients following NAC and its impact on the prognosis of BC patients. We conducted a study involving 126 patients with LABC. Clinicopathological parameters associated with pCR were subjected to univariate and multivariate analysis. Kaplan-Meier (KM) curves and the log-rank test were used to compare the statistical difference in prognosis in different groups of patients. Additionally, we used difference and consistency tests to examine the conversion of immunohistochemistry (IHC) markers following NAC. The status of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and molecular subtypes of BC were associated with pCR in the univariate analysis (all P < .05), which may be potential markers to predict pCR. HER2 was identified as an independent factor for predicting pCR in the multivariate analysis. The pCR rate of HER2-positive patients who received NAC combined targeted therapy was higher than that of patients who only received NAC (P = .003). The disease-free survival (DFS) rate of TNBC patients who achieved pCR was significantly higher than that of non-pCR TNBC patients (P = .026). The IHC marker conversion after NAC mainly existed in PR (P = .041). Ki67 expression decreased in the luminal B subtype and increased in the HER2 enriched subtype after NAC (all P < .001). Patients with Ki67 expression change after NAC had longer overall survival (OS) and DFS than unchanged patients (all P < .05). HER2-positive is an independent indicator for predicting pCR, and HE2-positive patients who received NAC combined targeted therapy were favorable to achieving pCR. IHC markers of BC patients exhibit varying degrees of alterations after NAC, and changes in Ki67 expression after NAC could serve as a marker to predict a better prognosis.

Relevance of the endoplasmic reticulum-mitochondria axis in cancer diagnosis and therapy

Dynamic interactions between organelles are responsible for a variety of intercellular functions, and the endoplasmic reticulum (ER)-mitochondrial axis is recognized as a representative interorganelle system. Several studies have confirmed that most proteins in the physically tethered sites between the ER and mitochondria, called mitochondria-associated ER membranes (MAMs), are vital for intracellular physiology. MAM proteins are involved in the regulation of calcium homeostasis, lipid metabolism, and mitochondrial dynamics and are associated with processes related to intracellular stress conditions, such as oxidative stress and unfolded protein responses. Accumulating evidence has shown that, owing to their extensive involvement in cellular homeostasis, alterations in the ER-mitochondrial axis are one of the etiological factors of tumors. An in-depth understanding of MAM proteins and their impact on cell physiology, particularly in cancers, may help elucidate their potential as diagnostic and therapeutic targets for cancers. For example, the modulation of MAM proteins is utilized not only to target diverse intracellular signaling pathways within cancer cells but also to increase the sensitivity of cancer cells to anticancer reagents and regulate immune cell activities. Therefore, the current review summarizes and discusses recent advances in research on the functional roles of MAM proteins and their characteristics in cancers from a diagnostic perspective. Additionally, this review provides insights into diverse therapeutic strategies that target MAM proteins in various cancer types.

TMEM43 promotes the development of hepatocellular carcinoma by activating VDAC1 through USP7 deubiquitination

Background

Transmembrane protein 43 (TMEM43), a member of the TMEM subfamily, is encoded by a highly conserved gene and widely expressed in most species from bacteria to humans. In previous studies, TMEM43 has been found to play an important role in a variety of tumors. However, the role of TMEM43 in cancer remains unclear.

Methods

We utilized the RNA sequencing (RNA-seq) and The Cancer Genome Atlas (TGCA) databases to explore and identify genes that may play an important role in the occurrence and development of hepatocellular carcinoma (HCC), such as TMEM43. The role of TMEM43 in HCC was explored through Cell Counting Kit-8 (CCK-8) cloning, flow cytometry, and Transwell experiments. The regulatory relationship between TMEM43 and voltage-dependent anion channel 1 (VDAC1) was investigated through coimmunoprecipitation (co-IP) and western blot (WB) experiments. WB was used to study the deubiquitination effect of ubiquitin-specific protease 7 (USP7) on TMEM43.

Results

In this study, we utilized the RNA-seq and TGCA databases to mine data and found that TMEM43 is highly expressed in HCC. The absence of TMEM43 in cancer cells was shown to inhibit tumor development. Further research detected an important regulatory relationship between TMEM43 and VDAC1. In addition, we found that USP7 affected the progression of HCC by regulating the ubiquitination level of TMEM43 through deubiquitination.

Conclusions

Our study demonstrated that USP7 participates in the growth of HCC tumors through TMEM43/VDAC1.Our results suggest that USP7/TMEM43/VDAC1 may have predictive value and represent a new treatment strategy for HCC.

Mitochondrial Calcium Uniporter (MCU) that Modulates Mitochondrial Calcium Uptake and Facilitates Endometrial Cancer Progression through Interaction with VDAC1

BACKGROUND

Although endometrial cancer represents a frequently diagnosed malignancy of the female reproductive tract, we know very little about the factors that control endometrial cancer.

OBJECTIVE

Our study was presented to investigate the function of MCU in endometrial tumorigenesis and the molecular mechanisms involved.

MATERIALS AND METHODS

A total of 94 endometrial cancer patients were recruited into our cohort. MCU and VDAC1 expression was examined in tumor and normal tissues via immunohistochemistry and immunofluorescence. Associations of MCU and VDAC1 expression with clinicopathological characteristics were evaluated. After transfection with shRNA targeting MCU or full-length MCU plasmids, clone formation, wound healing, transwell and MitoTracker Red staining were separately presented in Ishikawa and RL95-2 cells. Moreover, Western blotting or immunofluorescence was utilized to examine the expression of MCU, VDAC1, Na+/Ca2+/Li+ exchanger (NCLX), and β-catenin under VDAC1 knockdown and/or MCU overexpression or knockdown.

RESULTS

MCU and VDAC1 expression were prominently up-regulated in endometrial cancer tissues and were significantly associated with histological grade, depth of myometrial invasion and lymph node status. MCU up-regulation enhanced clone formation, migration, and mitochondrial activity of endometrial cancer cells. The opposite results were investigated when MCU was silenced. MCU or VDAC1 silencing reduced the expression of MCU, VDAC1, NCLX, and β-catenin. Moreover, VDAC1 knockdown alleviated the promoting effect of MCU overexpression on the above proteins.

CONCLUSION

This investigation demonstrated that MCU-induced mitochondrial calcium uptake plays a critical role in endometrial tumorigenesis through interaction with VDAC1.

Origin recognition complex subunit 1(ORC1) is a potential biomarker and therapeutic target in cancer

BACKGROUND

The origin recognition complex 1 (ORC1) is a large subunit of the origin recognition complex and acts as the master subunit of the precoding complex.

OBJECTIVE

To explore potential function and clinical significance of ORC1 in cancers.

METHODS

The expression level of ORC1 in different types of tumor tissues and matched normal tissues were detected by The Cancer Genome Atlas (TCGA) and validated by datasets from the gene expression omnibus (GEO) database. The association between ORC1 expression and infiltration levels of immune cell was analyzed. ORC1 and its co-expression genes were subjected to enrichment analysis to explore potential mechanisms in cancers, and the protein-protein interaction (PPI) network was constructed. Finally, the expression of ORC1 in tumor tissue and adjacent tissue was verified by immunohistochemistry (IHC).

RESULTS

ORC1 was highly expressed in the majority of tumors, and the expression level of ORC1 was associated with the pathological stages of ACC, LUAD, OV and SKCM. ORC1 was closely related with poor prognosis in ACC, LIHC, PAAD, READ and THCA. ORC1 in ACC and KICH was positively correlated with the infiltration level of immune cells while it was negatively correlated with the infiltration level of immune cells in THYM. Co-expression network analysis showed that CDCA3, GSG2, KIF2C, NCAPH and PLK1 were positively correlated with ORC1 in cancer, and enrichment analysis showed a correlation with cytosol, ATP binding and cell division. The expression of ORC1 in UCEC and KICH was higher than that in the adjacent tissues.

CONCLUSION

ORC1 over-expressed in most tumors and could be severed as a novel biomarker for diagnosis. This study revealed that ORC1 might inhibit tumor immunity and might be a potential therapeutic target in cancers.

Integrative analysis of the prognostic value and immune microenvironment of mitophagy-related signature for multiple myeloma

BACKGROUND

Multiple myeloma (MM) is a fatal malignant tumor in hematology. Mitophagy plays vital roles in the pathogenesis and drug sensitivity of MM.

METHODS

We acquired transcriptomic expression data and clinical index of MM patients from NCI public database, and 36 genes involved in mitophagy from the gene set enrichment analysis (GSEA) database. Least absolute shrinkage and selection operator (LASSO) Cox regression analysis was conducted to construct a risk score prognostic model. Kaplan-Meier survival analysis and receiver operation characteristic curves (ROC) were conducted to identify the efficiency of prognosis and diagnosis. ESTIMATE algorithm and immune-related single-sample gene set enrichment analysis (ssGSEA) was performed to uncover the level of immune infiltration. QRT-PCR was performed to verify gene expression in clinical samples of MM patients. The sensitivity to chemotherapy drugs was evaluated upon the database of the genomics of drug sensitivity in cancer (GDSC).

RESULTS

Fifty mitophagy-related genes were differently expressed in two independent cohorts. Ten out of these genes were identified to be related to MM overall survival (OS) rate. A prognostic risk signature model was built upon on these genes: VDAC1, PINK1, VPS13C, ATG13, and HUWE1, which predicted the survival of MM accurately and stably both in training and validation cohorts. MM patients suffered more adverse prognosis showed more higher risk core. In addition, the risk score was considered as an independent prognostic element for OS of MM patients by multivariate cox regression analysis. Functional pathway enrichment analysis of differentially expressed genes (DEGs) based on risk score showed terms of cell cycle, immune response, mTOR pathway, and MYC targets were obviously enriched. Furthermore, MM patients with higher risk score were observed lower immune scores and lower immune infiltration levels. The results of qRT-PCR verified VDAC1, PINK1, and HUWE1 were dysregulated in new diagnosed MM patients. Finally, further analysis indicated MM patients showed more susceptive to bortezomib, lenalidomide and rapamycin in high-risk group.

CONCLUSION

Our research provided a neoteric prognostic model of MM based on mitophagy genes. The immune infiltration level based on risk score paved a better understanding of the participation of mitophagy in MM.

Voltage-Dependent Anion Channel 1 Expression in Oral Malignant and Premalignant Lesions

BACKGROUND

The voltage-dependent anion channel 1 protein (VDAC1) plays a role in cellular metabolism and survival. It was found to be down or upregulated (overexpressed) in different malignancies but it was never studied in application to oral lesions. The purpose of this study was to retrospectively evaluate the expression of VDAC1 in biopsies of oral premalignant, malignant, and malignancy-neutral lesions and to examine the possible correlations to their clinicopathological parameters.

MATERIALS AND METHODS

103 biopsies including 49 oral squamous cell carcinoma, 33 epithelial dysplasia, and 21 fibrous hyperplasia samples were immunohistochemically stained with anti-VDAC1 antibodies for semi-quantitative evaluation. The antibody detection was performed with 3,3'-diaminobenzidine (DAB). The clinicopathological information was examined for possible correlations with VDAC1.

RESULTS

VDAC1 expression was lower in oral squamous cell carcinoma 0.63 ± 0.40 and in oral epithelial dysplasia 0.61 ± 0.36 biopsies compared to fibrous hyperplasia biopsies 1.45 ± 0.28 (p < 0.01 for both; Kruskal-Wallis test).

CONCLUSION

Oral squamous cell carcinoma and epithelial dysplasia tissues demonstrated decreased VDAC1 protein expression if compared to fibrous hyperplasia samples, but were not different from each other, suggesting that the involvement of VDAC1 in oral carcinogenesis is an early stage event, regulating cells to live or die.

Targeting the overexpressed mitochondrial protein VDAC1 in a mouse model of Alzheimer's disease protects against mitochondrial dysfunction and mitigates brain pathology

BACKGROUND

Alzheimer's disease (AD) exhibits mitochondrial dysfunctions associated with dysregulated metabolism, brain inflammation, synaptic loss, and neuronal cell death. As a key protein serving as the mitochondrial gatekeeper, the voltage-dependent anion channel-1 (VDAC1) that controls metabolism and Ca²⁺ homeostasis is positioned at a convergence point for various cell survival and death signals. Here, we targeted VDAC1 with VBIT-4, a newly developed inhibitor of VDAC1 that prevents its pro-apoptotic activity, and mitochondria dysfunction.

METHODS

To address the multiple pathways involved in AD, neuronal cultures and a 5 × FAD mouse model of AD were treated with VBIT-4. We addressed multiple topics related to the disease and its molecular mechanisms using immunoblotting, immunofluorescence, q-RT-PCR, 3-D structural analysis and several behavioral tests.

RESULTS

In neuronal cultures, amyloid-beta (Aβ)-induced VDAC1 and p53 overexpression and apoptotic cell death were prevented by VBIT-4. Using an AD-like 5 × FAD mouse model, we showed that VDAC1 was overexpressed in neurons surrounding Aβ plaques, but not in astrocytes and microglia, and this was associated with neuronal cell death. VBIT-4 prevented the associated pathophysiological changes including neuronal cell death, neuroinflammation, and neuro-metabolic dysfunctions. VBIT-4 also switched astrocytes and microglia from being pro-inflammatory/neurotoxic to neuroprotective phenotype. Moreover, VBIT-4 prevented cognitive decline in the 5 × FAD mice as evaluated using several behavioral assessments of cognitive function. Interestingly, VBIT-4 protected against AD pathology, with no significant change in phosphorylated Tau and only a slight decrease in Aβ-plaque load.

CONCLUSIONS

The study suggests that mitochondrial dysfunction with its gatekeeper VDAC1 is a promising target for AD therapeutic intervention, and VBIT-4 is a promising drug candidate for AD treatment.