SYPL1 Inhibits Apoptosis in Pancreatic Ductal Adenocarcinoma via Suppression of ROS-Induced ERK Activation

Hepatocellular carcinoma cells downregulate NADH:Ubiquinone Oxidoreductase Subunit B3 to maintain reactive oxygen species homeostasis

BACKGROUND

HCC is a leading cause of cancer-related death. The role of reactive oxygen species (ROS) in HCC remains elusive. Since a primary ROS source is the mitochondrial electron transport chain complex Ι and the NADH:ubiquinone Oxidoreductase Subunit B3 (NDUFB3), a complex I subunit, is critical for complex I assembly and regulates the associated ROS production, we hypothesize that some HCCs progress by hijacking NDUFB3 to maintain ROS homeostasis.

METHODS

NDUFB3 in human HCC lines was either knocked down or overexpressed. The cells were then analyzed in vitro for proliferation, migration, invasiveness, colony formation, complex I activity, ROS production, oxygen consumption, apoptosis, and cell cycle. In addition, the in vivo growth of the cells was evaluated in nude mice. Moreover, the role of ROS in the NDUFB3-mediated changes in the HCC lines was determined using cellular and mitochondrion-targeted ROS scavengers.

RESULTS

HCC tissues showed reduced NDUFB3 protein expression compared to adjacent healthy tissues. In addition, NDUFB3 knockdown promoted, while its overexpression suppressed, HCC cells' growth, migration, and invasiveness. Moreover, NDUFB3 knockdown significantly decreased, whereas its overexpression increased complex I activity. Further studies revealed that NDUFB3 overexpression elevated mitochondrial ROS production, causing cell apoptosis, as manifested by the enhanced expressions of proapoptotic molecules and the suppressed expression of the antiapoptotic molecule B cell lymphoma 2. Finally, our data demonstrated that the apoptosis was due to the activation of the c-Jun N-terminal kinase (JNK) signaling pathway and cell cycle arrest at G0/G1 phase.

CONCLUSIONS

Because ROS plays essential roles in many biological processes, such as aging and cancers, our findings suggest that NDFUB3 can be targeted for treating HCC and other human diseases.

Integrated transcriptomics uncovers an enhanced association between the prion protein gene expression and vesicle dynamics signatures in glioblastomas

BACKGROUND

Glioblastoma (GBM) is an aggressive brain tumor that exhibits resistance to current treatment, making the identification of novel therapeutic targets essential. In this context, cellular prion protein (PrPC) stands out as a potential candidate for new therapies. Encoded by the PRNP gene, PrPC can present increased expression levels in GBM, impacting cell proliferation, growth, migration, invasion and stemness. Nevertheless, the exact molecular mechanisms through which PRNP/PrPC modulates key aspects of GBM biology remain elusive.

METHODS

To elucidate the implications of PRNP/PrPC in the biology of this cancer, we analyzed publicly available RNA sequencing (RNA-seq) data of patient-derived GBMs from four independent studies. First, we ranked samples profiled by bulk RNA-seq as PRNPhigh and PRNPlow and compared their transcriptomic landscape. Then, we analyzed PRNP+ and PRNP- GBM cells profiled by single-cell RNA-seq to further understand the molecular context within which PRNP/PrPC might function in this tumor. We explored an additional proteomics dataset, applying similar comparative approaches, to corroborate our findings.

RESULTS

Functional profiling revealed that vesicular dynamics signatures are strongly correlated with PRNP/PrPC levels in GBM. We found a panel of 73 genes, enriched in vesicle-related pathways, whose expression levels are increased in PRNPhigh/PRNP+ cells across all RNA-seq datasets. Vesicle-associated genes, ANXA1, RAB31, DSTN and SYPL1, were found to be upregulated in vitro in an in-house collection of patient-derived GBM. Moreover, proteome analysis of patient-derived samples reinforces the findings of enhanced vesicle biogenesis, processing and trafficking in PRNPhigh/PRNP+ GBM cells.

CONCLUSIONS

Together, our findings shed light on a novel role for PrPC as a potential modulator of vesicle biology in GBM, which is pivotal for intercellular communication and cancer maintenance. We also introduce GBMdiscovery, a novel user-friendly tool that allows the investigation of specific genes in GBM biology.

ComProliM: A cell growth assay robust to initial cell number in co-culture system

Cell growth is conventionally quantified using CCK-8 or MTT assays, but these methods display considerable sensitivity to initial cell quantities. Inherent sampling errors during cell counting and seeding make it impossible to achieve an absolute equivalence of initial cell numbers, potentially confounding the results of CCK-8 or MTT assays. In the present study, we introduce a novel cell proliferation assay, ComProliM, predicated on cell competition theory. Both numeral simulations and empirical testing demonstrate that ComProliM index (CPMI) reliably represents cell growth rate and is not influenced by variations in initial cell number. Intriguingly, two adherent cells of differing fluorescence states are co-cultured, suggesting that ComProliM can be successfully employed in co-culture system cell proliferation assays, including, for instance, the exploration of subclone interactions. We anticipate ComProliM will provide a viable alternative for quantifying adherent cell growth rates, particularly in cases where conventional methodologies deliver inconsistent or ambiguous results.

Comparison of Tumour-Specific Phenotypes in Human Primary and Expandable Pancreatic Cancer Cell Lines

There is an ongoing need for patient-specific chemotherapy for pancreatic cancer. Tumour cells isolated from human tissues can be used to predict patients' response to chemotherapy. However, the isolation and maintenance of pancreatic cancer cells is challenging because these cells become highly vulnerable after losing the tumour microenvironment. Therefore, we investigated whether the cells retained their original characteristics after lentiviral transfection and expansion. Three human primary pancreatic cancer cell lines were lentivirally transduced to create expandable (Ex) cells which were then compared with primary (Pri) cells. No obvious differences in the morphology or epithelial-mesenchymal transition (EMT) were observed between the primary and expandable cell lines. The two expandable cell lines showed higher proliferation rates in the 2D and 3D models. All three expandable cell lines showed attenuated migratory ability. Differences in gene expression between primary and expandable cell lines were then compared using RNA-Seq data. Potential target drugs were predicted by differentially expressed genes (DEGs), and differentially expressed pathways (DEPs) related to tumour-specific characteristics such as proliferation, migration, EMT, drug resistance, and reactive oxygen species (ROS) were investigated using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. We found that the two expandable cell lines expressed similar chemosensitivity and redox-regulatory capability to gemcitabine and oxaliplatin in the 2D model as compared to their counterparts. In conclusion, we successfully generated expandable primary pancreatic cancer cell lines using lentiviral transduction. These expandable cells not only retain some tumour-specific biological traits of primary cells but also show an ongoing proliferative capacity, thereby yielding sufficient material for drug response assays, which may provide a patient-specific platform for chemotherapy drug screening.

Synaptophysin-like 2 expression correlates with lymph node metastasis and poor prognosis in colorectal cancer patients

BACKGROUND

Colorectal cancer (CRC) is one of the most common and fatal cancers worldwide. Synaptophysin-like 2 (SYPL2) is a neuroendocrine-related protein highly expressed in skeletal muscle and the tongue. The involvement of SYPL2 in CRC, including its level of expression and function, has not been evaluated.

AIM

To evaluate the correlations of SYPL2 expression with lymph node metastasis (LNM) and prognosis in patients with CRC.

METHODS

The levels of expression of SYPL2 in CRC and normal colorectal tissues were analyzed in multiple public and online databases. The associations between clinical variables and SYPL2 expression were evaluated statistically, and the associations between SYPL2 expression and prognosis in patients with CRC were analyzed using the Kaplan-Meier method and univariate/multivariate Cox regression analyses. SYPL2 expression was assessed in 20 paired CRC tissue and adjacent normal colorectal tissue samples obtained from Fuyang People’s Hospital, and the associations between SYPL2 expression and the clinical characteristics of these patients were investigated. Correlations between the levels of expression of SYPL2 and key targeted genes were determined by Pearson’s correlation analysis. The distribution of immune cells in these samples was calculated using the CIBERSORT algorithm. Gene set enrichment analysis (GSEA) was performed to evaluate the biofunction and pathways of SYPL2 in CRC.

RESULTS

SYPL2 expression was significantly lower in CRC tissue samples than in normal colorectal tissue samples (P < 0.05). High SYPL2 levels in CRC tissues correlated significantly with LNM (P < 0.05) and a poorer patient prognosis, including significantly shorter overall survival (OS) [hazard ratio (HR) = 1.9, P < 0.05] and disease-free survival (HR = 1.6, P < 0.05). High SYPL2 expression was an independent risk factor for OS in both univariate (HR = 2.078, P = 0.014) and multivariate (HR = 1.754, P = 0.018) Cox regression analyses. In addition, SYPL2 expression correlated significantly with the expression of KDR (P < 0.0001, r = 0.47) and the BRAF^V600E mutation (P < 0.05). Higher SYPL2 expression was associated with the enrichment of CD8 T-cells and M0 macrophages in the tumor microenvironment. GSEA revealed that SYPL2 was associated with the regulation of epithelial cell migration, vasculature development, pathways in cancer, and several vital tumor-related pathways.

CONCLUSION

SYPL2 expression was lower in CRC tissue than in normal colorectal tissue. Higher SYPL2 expression in CRC was significantly associated with LNM and poorer survival.

Unveiling the mechanism of action of nature-inspired anti-cancer compounds using a multi-omics approach

The 2020 global cancer registry has ranked breast cancer (BCa) as the most commonly diagnosed type of cancer and the most common cause of cancer-related deaths in women worldwide. Increasing resistance and significant side effects continue to limit the efficacy of anti-BCa drugs, hence the need to identify new drug targets and to develop novel compounds to overcome these limitations. Nature-inspired anti-cancer compounds are becoming increasingly popular since they often provide a relatively safe and effective alternative. In this study, we employed multi-omics techniques to gain insights into the relevant mechanism of action of two recently identified new nature-inspired anti-cancer compounds (SIMR3066 and SIMR3058). Discovery proteomics analysis combined with LC-MS/MS-based untargeted metabolomics analysis was performed on compound-treated vs DMSO-treated (control) MCF-7 cells. Downstream protein functional enrichment analysis showed that most of the responsive proteins were functionally associated with antigen processing and neutrophil degranulation, RNA catabolism and protein folding as well as cytoplasmic vesicle lumen and mitochondrial matrix formation. Consistent with the proteomics findings, metabolomic pathway analysis suggested that the differentially abundant compounds indicated altered metabolic pathways such as glycolysis, the Krebs cycle and oxidative phosphorylation. Furthermore, metabolomics-based enriched-for-action pathway analysis showed that the two compounds associate with mercaptopurine, thioguanine and azathioprine related pathways. Lastly, integrated proteomics and metabolomics analysis revealed that treatment of BCa with SIMR3066 disrupts several signaling pathways including p53-mediated apoptosis and the circadian entertainment pathway. Overall, the multi-omics approach we used in this study indicated that it is a powerful tool in probing the mechanism of action of lead drug candidates. SIGNIFICANCE: In this study we adopted a multi-omics (proteomics and metabolomics) strategy to learn more about the molecular mechanisms of action of nature-inspired potential anticancer drugs. Following treatment with SIMR3066 or SIMR3058, the integration of these multi-omics data sets revealed which biological pathways are altered in BCa cells. This study demonstrates that combining proteomics with metabolomics is a powerful method to investigate the mechanism of action of potential anticancer lead drug candidates.

Evaluation of fecal SYPL1 as a diagnostic biomarker in colorectal cancer

BACKGROUND

At present, there is still no ideal non-invasive biomarker for colorectal cancer (CRC) screening. Previously, we foundserum synaptophysin like 1 (SYPL1) served as a potential biomarker for CRC diagnosis. However, whether fecal SYPL1 (fSYPL1) are more sensitive and specific for CRC remains unclear.

METHODS

We analyzed fSYPL1 in controls (n = 70), adenoma patients (n = 80), CRC patients (n = 150) and postoperative CRC patients (n = 25) by ELISA.

RESULTS

SYPL1 was stable in feces. The fSYPL1 levels were significantly higher in CRC patients than in either controls or adenoma patients (P < 0.0001). ROC curves showed that fSYPL1 performed superbly in distinguishing CRC patients from controls (AUC = 0.947; 95% CI: 0.920 - 0.974, P < 0.0001, sensitivity: 80.67%, specificity: 100.00%), which showed much stronger performance than the traditional biomarkers (FOBT, CEA and CA19-9). Meanwhile, the fSYPL1 level positively correlated with tumor size, tumor invasion, lymph node invasion and clinical stage (P < 0.05). In addition, the detection rate of fSYPL1 was high in early CRC (75.00% in stage I and II). The fSYPL1 levels in CRC patients declined substantially after surgery (P = 0.0002). By means of a lower cut off level, 73.58% of high-risk adenomas were detected. The combination of fSYPL1 and FOBT performed better than the combination of plasma SYPL1, CEA and CA199 in distinguishing CRC patients from controls.

CONCLUSION

The fSYPL1 might be a potential biomarker for CRC screening, early diagnosis, prognosis prediction and therapeutic effect monitoring.

Semaphorin 3D inhibits proliferation and migration of papillary thyroid carcinoma by regulating MAPK/ERK signaling pathway

BACKGROUND

Semaphorin 3D (SEMA3D) plays an important role in the occurrence and development of multifarious cancers. However, the relationship between SEMA3D and papillary thyroid carcinoma (PTC) remains unclear. This study aimed to investigate the functions and mechanism of SEMA3D in papillary thyroid carcinoma (PTC).

METHODS

The expression of SEMA3D in PTC tissues and cell lines was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Western blotting and immunohistochemistry (IHC) were used to detect the expression of the related proteins. CCK-8 and colony formation assays and Transwell assays were used to evaluate cell proliferation and migration, respectively. A xenograft model was induced to further verify the effect of SEMA3D in vivo.

RESULTS

In this study, we found that SEMA3D was downregulated in PTC tissues and PTC cell lines (TPC-1 and BCPAP). The expression level of SEMA3D was significantly related to age (P < 0.01), extrathyroidal extension (P < 0.01), TNM stage (P < 0.01) and lymph node metastasis (P < 0.01). In vitro experiments showed that overexpression of SEMA3D inhibited the proliferation and migration of TPC-1 and BCPAP cells and that upregulated SEMA3D inhibited the phosphorylation of ERK and the expression of the phenotype-related proteins PCNA and MMP2. In addition, SEMA3D overexpression inhibited tumour growth in vivo.

CONCLUSION

In this study, we found that SEMA3D is significantly downregulated in PTC tissues. SEMA3D inhibits the proliferation and migration of PTC cells and suppresses tumour growth in vivo, possibly partially through the MAPK/ERK signalling pathway, suggesting that SEMA3D may be a reliable molecular marker for the diagnosis and treatment of PTC.

ACAGT-007a, an ERK MAPK Signaling Modulator, in Combination with AKT Signaling Inhibition Induces Apoptosis in KRAS Mutant Pancreatic Cancer T3M4 and MIA-Pa-Ca-2 Cells

The mitogen-activated protein kinase (MAPK)/ERK and phosphatidylinositol-3 kinase (PI3K)/AKT pathways are dysregulated in various human cancers, including pancreatic ductal adenocarcinoma (PDAC), which has a very poor prognosis due to its lack of efficient therapies. We have previously identified ACAGT-007a (GT-7), an anti-cancer compound that kills ERK-active melanoma cells by inducing ERK-dependent apoptosis. Here, we investigated the apoptosis-inducing effect of GT-7 on three PDAC cell lines and its relevance with the MAPK/ERK and PI3K/AKT signaling pathways. GT-7 induced apoptosis in PDAC cells with different KRAS mutations (MIA-Pa-Ca-2 (KRAS G12C), T3M4 (KRAS Q61H), and PANC-1 (KRAS G12D)), being T3M4 most susceptible, followed by MIA-Pa-Ca-2, and PANC-1 was most resistant to apoptosis induction by GT-7. GT-7 stimulated ERK phosphorylation in the three PDAC cells, but only T3M4 displayed ERK-activation-dependent apoptosis. Furthermore, GT-7 induced a marked down-regulation of AKT phosphorylation after a transient peak in T3M4, whereas PANC-1 displayed the strongest and most sustained AKT activation, followed by MIA-Pa-Ca-2, suggesting that sustained AKT phosphorylation as a determinant for the resistance to GT-7-mediated apoptosis. Consistently, a PI3K inhibitor, Wortmannin, abolished AKT phosphorylation and enhanced GT-7-mediated apoptosis in T3M4 and MIA-Pa-Ca-2, but not in PANC-1, which showed residual AKT phosphorylation. This is the first report that ERK stimulation alone or in combination with AKT signaling inhibition can effectively induce apoptosis in PDAC and provides a rationale for a novel concurrent targeting of the PI3K/AKT and ERK pathways.

Whole-genome analysis of Nigerian patients with breast cancer reveals ethnic-driven somatic evolution and distinct genomic subtypes

Black women across the African diaspora experience more aggressive breast cancer with higher mortality rates than white women of European ancestry. Although inter-ethnic germline variation is known, differential somatic evolution has not been investigated in detail. Analysis of deep whole genomes of 97 breast cancers, with RNA-seq in a subset, from women in Nigeria in comparison with The Cancer Genome Atlas (n = 76) reveal a higher rate of genomic instability and increased intra-tumoral heterogeneity as well as a unique genomic subtype defined by early clonal GATA3 mutations with a 10.5-year younger age at diagnosis. We also find non-coding mutations in bona fide drivers (ZNF217 and SYPL1) and a previously unreported INDEL signature strongly associated with African ancestry proportion, underscoring the need to expand inclusion of diverse populations in biomedical research. Finally, we demonstrate that characterizing tumors for homologous recombination deficiency has significant clinical relevance in stratifying patients for potentially life-saving therapies.

Breast cancer heterogeneity and tumour evolutionary trajectories remain largely unknown among women of African ancestry. Here, the authors perform whole genome and transcriptome sequencing of Nigerian breast cancer patients and identify unique evolutionary phenomena.

Metformin Potentiates the Effects of Anlotinib in NSCLC via AMPK/mTOR and ROS-Mediated Signaling Pathways

Anlotinib is a novel multi-targeted tyrosine kinase inhibitor with activity against soft tissue sarcoma, small cell lung cancer, and non-small cell lung cancer (NSCLC). Potentiating the anticancer effect of anlotinib in combination strategies remains a clinical challenge. Metformin is an oral agent that is used as a first-line therapy for type 2 diabetes. Interesting, metformin also exerts broad anticancer effects through the activation of AMP-activated protein kinase (AMPK) and inhibition of mammalian target of rapamycin (mTOR). Here, we evaluated the possible synergistic effect of anlotinib and metformin in NSCLC cells. The results showed that metformin enhanced the antiproliferative effect of anlotinib. Moreover, anlotinib combined with metformin induced apoptosis and oxidative stress, which was associated with the activation of AMPK and inhibition of mTOR. Reactive oxygen species (ROS)- mediated p38/JNK MAPK and ERK signaling may be involved in the anticancer effects of this combination treatment. Our results show that metformin potentiates the efficacy of anlotinib in vivo by increasing the sensitivity of NSCLC cells to the drug. These data provide a potential rationale for the combination of anlotinib and metformin for the treatment of patients with NSCLC or other cancers.

Proteomic Investigation of Glyceraldehyde-Derived Intracellular AGEs and Their Potential Influence on Pancreatic Ductal Cells

Glyceraldehyde-derived advanced glycation end products (AGEs) play an important role in the pathogenesis of many diseases including cancer. Accumulation of intracellular AGEs could stimulate cancer induction and facilitate cancer progression. We evaluated the toxic effect of glyceraldehyde-derived intracellular AGEs on normal and malignant pancreatic ductal cells by assessing the cell viability, toxicity, and oxidative stress, followed by proteomic analysis. Our functional studies showed that pancreatic cancer cells (PANC-1 and MIA PaCa-2) were more resistant to glyceraldehyde treatment compared to normal pancreatic ductal epithelial cells (HPDE), while cytotoxicity effects were observed in all cell types. Furthermore, using ¹³C isotopic labeled glyceraldehyde, the proteomic data revealed a dose-dependent increment of the number of glycation adducts in both these cell types. HPDE cells showed a higher number of intracellular AGEs compared to cancer cells. At a molecular level, the glycations in the lysine residues of proteins showed a concurrent increase with the concentration of the glyceraldehyde treatment, while the arginine glycations appeared to be less affected by the glyceraldehyde doses. Further pathway analysis of these glycated proteins suggested that the glycated proteins participate in important biological processes that are major hallmarks of cancer initiation and progression, including metabolic processes, immune response, oxidative stress, apoptosis, and S100 protein binding.

Synergistic anticancer effect of docosahexaenoic acid and isoliquiritigenin on human colorectal cancer cells through ROS-mediated regulation of the JNK and cytochrome c release

A large body of research has demonstrated a synergistic anticancer effect between docosahexaenoic acid (DHA) and standard chemotherapy regimens against colorectal cancer (CRC). In this study, we investigated the chemotherapeutic potential of cotreatment with DHA and isoliquiritigenin (ISL) against CRC HCT-116 cells. Apoptosis was confirmed by Annexin V/PI staining and expression of apoptosis-associated proteins. The synergistic effect of DHA and ISL combination on apoptosis was detected using combination index approaches. Flow cytometry was carried out using fluorescent probes to measure the production of reactive oxygen species (ROS). DHA and ISL in combination synergistically enhanced the decrease in cell viability versus the compounds used alone. Moreover, we demonstrated that the synergistic anti-CRC activity of cotreatment with these two compounds was achieved by inducing the apoptosis caspase-dependently mediated through augmented ROS generation followed by increased Fas ligand mRNA expression and cytochrome c release. Our data also demonstrated that cotreating with DHA and ISL strongly upregulated the phosphorylation of ERK and JNK, which are functionally associated with ROS induced by the two compounds in combination. Interestingly, further study revealed that inhibiting ERK phosphorylation strongly enhanced Fas ligand mRNA expression and the combination of the two compounds induced stronger cytotoxicity, whereas inhibiting JNK phosphorylation significantly reduced the apoptotic signals mediated by cotreatment with these two compounds. Excessive ROS-induced JNK activation and cytochrome c release from mitochondria played a key role in the synergistic anticancer activity of CRC cells by cotreating with DHA and ISL.