Emerging roles of dehydrogenase/reductase member 2 (DHRS2) in the pathology of disease

DHRS2-induced SPHK1 downregulation contributes to the cell growth inhibition by Trichothecin in colorectal carcinoma

BACKGROUND

Deregulation of lipid metabolism is one of the most prominent metabolic features in cancer. The activation of sphingolipid metabolic pathways affects the proliferation, invasion, angiogenesis, chemoresistance, and immune escape of tumors, including colorectal cancer (CRC). Dehydrogenase/reductase member 2 (DHRS2), which belongs to the short-chain dehydrogenase/reductase (SDR) family, has been reported to participate in the regulation of lipid metabolism and impact on cancer progression. Trichothecin (TCN) is a sesquiterpenoid metabolite originating from an endophytic fungus of the herbal plant Maytenus hookeri Loes. Studies have shown that TCN exerts a broad-spectrum antitumor activity.

METHODS

We evaluated the proliferative ability of CRC cells by CCK8 and colony formation assays. A metabolite profiling using liquid chromatography coupled with mass spectrometry (LC/MS) was adopted to identify the proximal metabolite changes linked to DHRS2 overexpression. RNA stability assay and RNA immunoprecipitation (RIP) experiments were applied to determine the post-transcriptional regulation of SPHK1 expression by DHRS2. We used flow cytometry to detect changes in cell cycle and cell apoptosis of CRC cells in the absence or presence of TCN.

RESULTS

We demonstrate that DHRS2 hampers the sphingosine kinases 1 (SPHK1)/sphingosine 1-phosphate (S1P) metabolic pathway to inhibit CRC cell growth. DHRS2 directly binds to SPHK1 mRNA to accelerate its degradation in a post-transcriptionally regulatory manner. Moreover, we illustrate that SPHK1 downregulation induced by DHRS2 contributes to TCN-induced growth inhibition of CRC.

CONCLUSIONS

The present study provides a mechanistic connection among metabolic enzymes, metabolites, and the malignant progression of CRC. Moreover, TCN could be developed as a potential pharmacological tool against CRC by the induction of DHRS2 and targeting SPHK1/S1P metabolic pathway.

Characterization of the dehydrogenase-reductase DHRS2 and its involvement in histone deacetylase inhibition in urological malignancies

BACKGROUND

Being implicated during tumor migration, invasion, clonogenicity, and proliferation, the nicotinamide adenine dinucleotide (NAD)/-phosphate (NADP)-dependent dehydrogenase/reductase member 2 (DHRS2) has been considered to be induced upon inhibition of histone deacetylases (HDACi). In this study, we evaluated the current knowledge on the underlying mechanisms of the (epi)genetic regulation of DHRS2, as well as its function during tumor progression.

METHODS

DHRS2 expression was evaluated on mRNA- and protein-level upon treatment with HDACi by means of qRT-PCR and western blot analyses, respectively. Re-analysis of RNA-sequencing data gained insight into expression of specific DHRS2 isoforms, while re-analysis of ATAC-sequencing data shed light on the chromatin accessibility at the DHRS2 locus. Further examination of the energy and lipid metabolism of HDACi-treated urologic tumor cells was performed using liquid chromatography-mass spectrometry.

RESULTS

Enhanced DHRS2 expression levels upon HDACi treatment were directly linked to an enhanced chromatin accessibility at the DHRS2 locus. Particularly the DHRS2 ENST00000250383.11 protein-coding isoform was increased upon HDACi treatment. Application of the HDACi quisinostat only mildly influenced the energy metabolism of urologic tumor cells, though, the analysis of the lipid metabolism showed diminished sphingosine levels, as well as decreased S1P levels. Also the ratios of S1P/sphingosine and S1P/ceramides were reduced in all four quisinostat-treated urologic tumor cells.

CONCLUSIONS

With the emphasis on urologic malignancies (testicular germ cell tumors, urothelial, prostate, and renal cell carcinoma), this study concluded that elevated DHRS2 levels are indicative of a successful HDACi treatment and, thereby offering a novel putative predictive biomarker.

The landscape of rare genetic variation associated with inflammatory bowel disease and Parkinson's disease comorbidity

BACKGROUND

Inflammatory bowel disease (IBD) and Parkinson's disease (PD) are chronic disorders that have been suggested to share common pathophysiological processes. LRRK2 has been implicated as playing a role in both diseases. Exploring the genetic basis of the IBD-PD comorbidity through studying high-impact rare genetic variants can facilitate the identification of the novel shared genetic factors underlying this comorbidity.

METHODS

We analyzed whole exomes from the BioMe BioBank and UK Biobank, and whole genomes from a cohort of 67 European patients diagnosed with both IBD and PD to examine the effects of LRRK2 missense variants on IBD, PD and their co-occurrence (IBD-PD). We performed optimized sequence kernel association test (SKAT-O) and network-based heterogeneity clustering (NHC) analyses using high-impact rare variants in the IBD-PD cohort to identify novel candidate genes, which we further prioritized by biological relatedness approaches. We conducted phenome-wide association studies (PheWAS) employing BioMe BioBank and UK Biobank whole exomes to estimate the genetic relevance of the 14 prioritized genes to IBD-PD.

RESULTS

The analysis of LRRK2 missense variants revealed significant associations of the G2019S and N2081D variants with IBD-PD in addition to several other variants as potential contributors to increased or decreased IBD-PD risk. SKAT-O identified two significant genes, LRRK2 and IL10RA, and NHC identified 6 significant gene clusters that are biologically relevant to IBD-PD. We observed prominent overlaps between the enriched pathways in the known IBD, PD, and candidate IBD-PD gene sets. Additionally, we detected significantly enriched pathways unique to the IBD-PD, including MAPK signaling, LPS/IL-1 mediated inhibition of RXR function, and NAD signaling. Fourteen final candidate IBD-PD genes were prioritized by biological relatedness methods. The biological importance scores estimated by protein-protein interaction networks and pathway and ontology enrichment analyses indicated the involvement of genes related to immunity, inflammation, and autophagy in IBD-PD. Additionally, PheWAS provided support for the associations of candidate genes with IBD and PD.

CONCLUSIONS

Our study confirms and uncovers new LRRK2 associations in IBD-PD. The identification of novel inflammation and autophagy-related genes supports and expands previous findings related to IBD-PD pathogenesis, and underscores the significance of therapeutic interventions for reducing systemic inflammation.

STAMBPL1 promotes the progression of lung adenocarcinoma by inhibiting DHRS2 expression

BACKGROUND

Lung cancer is responsible for the majority of cancer deaths in the world. We found a significant increase of STAMBPL1 expression in lung adenocarcinoma (LUAD) tissues and cells. However, its mechanism has not been clarified.

METHODS

LUAD tissues and adjacent normal tissues were collected from 62 patients treated in the First Affiliated Hospital of Wenzhou Medical University from August 2018 to August 2021. In vivo, the clinical data and STAMBPL1 expression of 62 patients with LUAD were analyzed by qPCR. In vitro, cell experiments were carried out after STAMBPL1 knockdown in A549 and H1299 cells to determine cell growth, migration rate, evasiveness, colony-forming ability, and apoptosis. Gene sequencing was used to explore the expression of various genes in A549 and H1299 cells to verify that DHRS2 was up-regulated after STAMBPL1 knockdown; cell experiments further detected the role of the DHRS2 gene after DHRS2 overexpression in A549 and H1299 cells. A rescue experiment was conducted to certify that STAMBPL1 promotes NSCLC progression by regulating DHRS2 expression.

RESULTS

After STAMBPL1 knockdown by siRNA. Migration, invasion, colony formation, and proliferation of siRNA groups were suppressed than those of NC groups in A549 and H1299 cells, while the cell apoptosis rate of siRNA groups increased significantly. By using gene-sequence analysis, we found that the expression level of the DHRS2 gene was up-regulated in STAMBPL1 siRNA groups, compared with STAMBPL1 NC (negative control) groups in A549 and H1299, which was verified by qPCR and WB. Further experiments showed that the DHRS2 OE group was suppressed in cell proliferation, migration, and invasion in the A549 and H1299 cell lines compared to the DHRS2 NC group, while DHRS2 OE group was significantly enhanced in the cell apoptosis in the A549 and H1299 cell lines. According to the rescue experiment, cell proliferation, migration, and invasion of the STAMBPL1 SI+DHRS2 SI group were enhanced compared with the STAMBPL1 SI+DHRS2 NC group in A549 and H1299 cells, while the STAMBPL1 SI+DHRS2 OE group were further decreased.

CONCLUSIONS

The expression of STAMBPL1 mRNA is significantly up-regulated in LUAD, promoting the progression of LUAD by down-regulating the expression of DHRS2 and acting as a potential biomarker of LUAD.

Regulatory mechanism of DHRS2-modified human umbilical cord mesenchymal stem cells-derived exosomes in prostate cancer cell proliferation and apoptosis

Prostate cancer (PCa) is a prevalent cause of morbidity and mortality. DHRS2-modified human umbilical cord mesenchymal stem cells-derived exosomes (hUC-MSCs-derived exos) function in PCa. We explored the mechanism of DHRS2-modified hUC-MSCs-derived exos in PCa cell malignant behaviors. DHRS2 expression levels in WPMY-1 cells and 4 PCa cell lines were detected by RT-qPCR and Western blot. 22Rv1/DU145 cells with high/low DHRS2 expression were selected to establish the low/high DHRS2 expression models by transfection. Cell proliferation and apoptosis were detected by CCK-8, colony formation assays, and flow cytometry. hUC-MSCs were identified by oil red O, alizarin staining, and flow cytometry. Exos were extracted from hUC-MSCs by ultracentrifugation and identified by transmission electron microscopy, Nano series-Nano-ZS, and Western blot. DU145 cells were selected for in vitro study to further study the effects of DHRS2-modified exos on cell proliferation and apoptosis. The effect of DHRS2-modified exos on cell cycle distribution was detected by flow cytometry. DHRS2 was repressed in PCa cells. DHRS2 overexpression suppressed PCa cell proliferation and promoted apoptosis. Exos were successfully isolated from hUC-MSC. DHRS2-modified hUC-MSCs-derived exos carried DHRS2 into PCa cells and blocked malignant behaviors. Briefly, DHRS2 was repressed in PCa cells. DHRS2-modified hUC-MSCs-derived exos blocked PCa cell proliferation and enhanced apoptosis.

DHRS2 inhibits cell growth and metastasis in ovarian cancer by downregulation of CHKα to disrupt choline metabolism

The short-chain dehydrogenase/reductase (SDR) superfamily has essential roles in lipid metabolism and redox sensing. In recent years, accumulating evidence highlights the emerging association between SDR family enzymes and cancer. Dehydrogenase/reductase member 2(DHRS2) belongs to the NADH/NADPH-dependent SDR family, and extensively participates in the regulation of the proliferation, migration, and chemoresistance of cancer cells. However, the underlying mechanism has not been well defined. In the present study, we have demonstrated that DHRS2 inhibits the growth and metastasis of ovarian cancer (OC) cells in vitro and in vivo. Mechanistically, the combination of transcriptome and metabolome reveals an interruption of choline metabolism by DHRS2. DHRS2 post-transcriptionally downregulates choline kinase α (CHKα) to inhibit AKT signaling activation and reduce phosphorylcholine (PC)/glycerophosphorylcholine (GPC) ratio, impeding choline metabolism reprogramming in OC. These actions mainly account for the tumor-suppressive role of DHRS2 in OC. Overall, our findings establish the mechanistic connection among metabolic enzymes, metabolites, and the malignant phenotype of cancer cells. This could result in further development of novel pharmacological tools against OC by the induction of DHRS2 to disrupt the choline metabolic pathway.

PGC1α-mediated fatty acid oxidation promotes TGFβ1-induced epithelial-mesenchymal transition and metastasis of nasopharyngeal carcinoma

AIM

Cancer cells frequently undergo metabolic reprogramming, which contributes to tumorigenicity and malignancy. Unlike primary cancers, during the process of invasion and distal dissemination, cancer cells are deficient in ATP due to damaged glucose transport. Cells need to rewire metabolic programs to overcome nutrient and energy crises, maintaining survival and forming metastasis. However, the underlying mechanism has not been well understood. We elucidated the metabolic alteration in TGFβ1-induced epithelial-mesenchymal transition (EMT) and metastasis of nasopharyngeal carcinoma (NPC).

MAIN METHODS

Fluorescent Bodipy fatty acid probe, UPLC-MS/MS analysis, β-oxidation assay, cellular ATP and NADPH/NADP measurement, and Oil Red-O staining were performed to evaluate the activation of FAO pathways in the TGFβ1-induced EMT of NPC cells. Three-dimensional (3D) invasion assay and metastatic animal model were applied to assess the invasive and metastatic capacity of NPC cells.

KEY FINDINGS

Our current findings reveal that PGC1α-mediated FAO promotes TGFβ1-induced EMT and metastasis of NPC cells. Mechanically, TGFβ1 up-regulates AMPKα1 to activate PGC1α, which transcriptionally boosts FAO-associated genes. The metabolic rewiring mediated by PGC1α facilitates EMT, invasion, and metastasis of NPC.

SIGNIFICANCE

The present study aims to establish the mechanistic connection between energy metabolic reprogramming and the aggressive phenotype of NPC. These actions further provide new opportunities for developing of novel therapeutics for NPC by targeting PGC1α/ FAO signaling.

Transposons: Unexpected players in cancer

Transposons are repetitive DNA sequences encompassing about half of the human genome. They play a vital role in genome stability maintenance and contribute to genomic diversity and evolution. Their activity is regulated by various mechanisms considering the deleterious effects of these mobile elements. Various genetic risk factors and environmental stress conditions affect the regulatory pathways causing alteration of transposon expression. Our knowledge of the biological role of transposons is limited especially in various types of cancers. Retrotransposons of different types (LTR-retrotransposons, LINEs and SINEs) regulate a plethora of genes that have a role in cell reprogramming, tumor suppression, cell cycle, apoptosis, cell adhesion and migration, and DNA repair. The regulatory mechanisms of transposons, their deregulation and different mechanisms underlying transposon-mediated carcinogenesis in humans focusing on the three most prevalent types, lung, breast and colorectal cancers, were reviewed. The modes of regulation employed include alternative splicing, deletion, insertion, duplication in genes and promoters resulting in upregulation, downregulation or silencing of genes.

ACSL family: The regulatory mechanisms and therapeutic implications in cancer

Accumulating evidence shows that deregulation of fatty acid (FA) metabolism is associated with the development of cancer. Long-chain acyl-coenzyme A synthases (ACSLs) are responsible for activating long-chain FAs and are frequently deregulated in cancers. Among the five mammalian ACSL family members, ACSL1 is involved in the TNFα-mediated pro-inflammatory phenotype and mainly facilitates cancer progression. ACSL3 is an androgen-responsive gene. High ACSL3 expression has been detected in a variety of cancers, including melanoma, triple-negative breast cancer (TNBC) and high-grade non-small cell lung carcinoma (NSCLC), and correlates with worse prognosis of patients with these diseases. ACSL4 can exert opposing roles acting as a tumor suppressor or as an oncogene depending on the specific cancer type and tissue environment. Moreover, ACSL4 behaves as a crucial regulator in ferroptosis that is defined as a cell death process caused by iron-dependent peroxidation of lipids. ACSL5 is nuclear-coded and expressed in the mitochondria and physiologically participates in the pro-apoptotic sensing of cells. ACSL5 mainly acts as a tumor suppressor in cancers. ACSL6 downregulation has been observed in many forms of cancers, except in colorectal cancer (CRC). Here, we address the differential regulatory mechanisms of the ACSL family members as well as their functions in carcinogenesis. Moreover, we enumerate the clinical therapeutic implications of ACSLs, which might serve as valuable biomarkers and therapeutic targets for precision cancer treatment.