Alpha Subunits Of Prolyl 4-hydroxylase Research Articles

P4HA3 promotes head and neck squamous cell carcinoma progression via the WNT/β-catenin signaling pathway

Here, we explored the role of Prolyl 4-Hydroxylase Subunit Alpha 3 (P4HA3), the most recently identified member of the prolyl-4-hydroxylase (P4H) family, in head and neck squamous cell carcinoma (HNSCC) progression. P4HA3 is upregulated during cancer progression; however, its specific role in HNSCC progression remains elusive. Thus, this study aimed to elucidate the regulatory function of P4HA3 in HNSCC development and progression and to describe the underlying mechanisms. Initially, we analyzed the correlation between the expression of P4HA3 and the WNT pathway genes and clinicopathologic features in HNSCC based on microarray data from The Cancer Genome Atlas (TCGA). Next, we used Gene Oncology (GO) functional data to describe several potentially associated pathways in HNSCC. Then, we knocked down P4HA3 in SCC15 and SCC25 cells, two classic HNSCC cell lines, and assessed the resulting changes using RT-qPCR. Furthermore, we used Western blot to evaluate the regulatory role of P4HA3 in the epithelial-to-mesenchymal transition (EMT) and the WNT/β-catenin signaling pathway. To explore the effect of P4HA3 knockdown on tumor progression, in vivo experiments were conducted using a murine model. Immunohistochemistry assays were then employed to identify proteins associated with EMT and the WNT/β-catenin signaling pathway in tumor tissues. Upregulated P4HA3 in HNSCC patient tumor tissues was positively correlated with poor prognosis. Notably, P4HA3 knockdown significantly inhibited the proliferative and invasive abilities of HNSCC. The levels of genes and proteins associated with EMT and the WNT/β-catenin signaling pathway were also markedly reduced by P4HA3 knockdown. Importantly, the in vivo experiments demonstrated that P4HA3 can promote subcutaneous tumorigenesis in nude mice and knockdown of P4HA3 induce a significant ihibitation of EMT and WNT/β-catenin pathway detected by immunohistochemistry assay in tumor tissues. In summary, we demonstrated that P4HA3 is a promising diagnostic and therapeutic biomarker for HNSCC. As an oncogene, P4HA3 increases HNSCC proliferation by inducing the EMT and activating the WNT/β-catenin signaling pathway.

Abstract 4139: Prolyl 4-hydroxylase subunit alpha 1 acts as a novel target for lung adenocarcinoma brain metastasis

Abstract Lung cancer is the most lethal cancer worldwide, with a high incidence of distant metastasis. Many lung adenocarcinoma (LUAD) patients experience brain metastasis during the disease process with unfavorable prognosis. Our previous study has discovered that P4HA1 was exclusively upregulated in brain metastatic cells. Through the analysis of single-cell RNA sequencing of LUAD samples, we found that the expression of P4HA1 in brain metastatic tumor cells is higher than that in primary tumor cells. This finding was further confirmed by immunohistochemical staining. Significantly, a strong presence of P4HA1 in primary tumors is associated with a reduced duration of disease-free survival in individuals with LUAD. Overexpression of P4HA1 in A549 and PC9 cell lines significantly increased the incidence of brain metastasis in BALB/c nude mice, whereas knockdown of P4HA1 in high brain metastatic cells significantly decreased the incidence of brain metastasis and reduced the tumor foci in brain with improved survival. Utilization of DHB, a P4HA1 inhibitor, exerts both therapeutic and preventive effects in relieving brain metastases in nude mice. Furthermore, remarkable inhibition of tumor growth by DHB was observed in patient derived xenograft (PDX) models. RNA sequencing analysis demonstrated that the reduction of P4HA1 expression had a substantial impact on cell adhesion and extracellular matrix (ECM)-receptors interactions. Western blotting analysis verified that the decrease in P4HA1 expression led to a drop in the expression of adhesion molecules ICAM1, VCAM1, NCAM1, as well as integrin molecules ITGA2 and ITGA3. Furthermore, when endothelial cells were co-cultured with conditioned medium from tumor cells, it was observed that the expression of the tight junction molecule ZO1 was reduced after co-culturing with conditioned medium from P4HA1 knockdown A549 cells. The results from the in vitro blood-brain barrier (BBB) model and in vivo biofluorescence imaging indicate that P4HA1 promoted brain metastasis of LUAD via modulating the ability of tumor cells to cross the blood-brain barrier. In conclusion, our study reveals that overexpression of P4HA1 promotes metastatic spread to the brain, and targeting P4HA1 could be a promising therapeutic strategy for the treatment of lung adenocarcinoma brain metastasis. Citation Format: Yan He, Zhenyu Luo, Yucheng Dong, Rui Wan, Xue Zhang, Hua Bai, Jie Wang. Prolyl 4-hydroxylase subunit alpha 1 acts as a novel target for lung adenocarcinoma brain metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4139.

Abstract 5973: Targeting prolyl 4-hydroxylase subunit alpha 1 with a small molecule inhibitor, diethyl-pythiDC, reduces pancreatic ductal adenocarcinoma growth and metastasis

Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease that has a 5-yearrelative survival rate of less than 9%. It is the fourth leading cause of cancer-associated mortality,and is projected to become the second leading cause of cancer-related deaths by 2030. Since most(~80%) PDACs are diagnosed at late stages (metastasized), there is an urgent need to identifymolecular determinants that regulate PDAC progression and serve as candidates for therapeutictargeting. Prolyl 4-hydroxylase subunit alpha 1 (P4HA1) is the major isoform overexpressed inmost cancers, including PDAC. In PDAC, high expression of P4HA1 is associated with tumorprogression and poor clinical outcomes. Thus, we investigated if targeting P4HA1 in PDAC witha small molecule inhibitor; diethyl-pythiDC, had an inhibitory effect on cell proliferation, tumorprogression/growth, and metastasis. Methods: To demonstrate the therapeutic efficacy of diethyl-pythiDC, we performed MTT, colonyformation, wound healing, Transwell, and western blot assays in various PDAC cell lines. Tumorgrowth and metastasis was evaluated with xenografts in NOD/SCID/IL2γ receptor-null (NSG)mice. Additionally, expression of P4HA1 in human PDAC and in adjacent normal pancreatictissues was assessed. Results: In human PDACs, there was elevated expression of P4HA1 protein relative to adjacentnormal pancreatic tissues. Treatment of various PDAC cells (S2VP10, MIA PaCa2, BxPC-3, andPANC-1) with diethyl-pythiDC reduced cell proliferation and colony formation, and inducedG2/M cell cycle arrest. Diethyl-pythiDC reduced migration and invasion of PDAC cells bymodulating epithelial-mesenchymal transition (EMT) markers (N-cadherin, E-cadherin, andvimentin). In addition, diethyl-pythiDC reduced the expression of argonaute-2 (AGO2), acomponent of microRNA biogenesis implicated in tumorigenesis, and its downstream target,matrix metalloproteinase (MMP1). In preclinical animal models of PDAC, diethyl-pythiDCreduced tumor growth and metastasis. Furthermore, in xenograft tumors, diethyl-pythiDCtreatment reduced the expression of AGO2, MMP1, and the proliferative marker, PCNA, andmodulated proteins of the EMT. Conclusions: Treatment with diethyl-pythiDC reduces PDAC progression by decreasing cellproliferation, arresting cells in the G2/M phase, downregulating AGO2/MMP1 expression, andmodulating the EMT. These findings suggest that targeting P4HA1 by diethyl-pythiDC could be aviable strategy to improve treatment for PDACs, particularly those expressing high levels ofP4HA1. They also provide a basis to conduct clinical trials to assess the utility of targeting P4HA1by diethyl-pythiDC. Citation Format: Farrukh Afaq, Mohd Khushman, Prachi Bajpai, Sameer Al Diffalha, Dennis Otali, Sooryanarayana Varambally, Upender Manne. Targeting prolyl 4-hydroxylase subunit alpha 1 with a small molecule inhibitor, diethyl-pythiDC, reduces pancreatic ductal adenocarcinoma growth and metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5973.

P4HA3 promotes colon cancer cell escape from macrophage phagocytosis by increasing phagocytosis immune checkpoint CD47 expression.

Cancer immunotherapies have greatly changed the prospects for the therapy of many malignancies, including colon cancer. Macrophages as the effectors of cancer immunotherapy provide considerable promise for cancer treatment. Prolyl 4-hydroxylase subunit alpha 3 (P4HA3) plays a cancer-promoting role in a variety of cancers, including colon cancer. In the present work, we provided evidence for the first time that P4HA3 promoted colon cancer cell escape from macrophage phagocytosis, and preliminarily explored its possible molecular mechanism. Immunohistochemistry was used to detect the expression of P4HA3 in tissues. Bioinformatics methods were used to analyze the tumor public databases (including TCGA database and GEO database). Macrophage phagocytosis assay and flow cytometric analysis were used to detect the phagocytic capacity of macrophages. Western blot and qRT-PCR were used to detect the expression of related markers (such as P4HA3, CD47, CD24, IL-34, and M-CSF). First, we found that P4HA3 was significantly and highly expressed in both colon cancer tissues and cells, and that P4HA3 had a positive correlation with lymph node metastasis, Dukes stage and also strongly correlated with poorer survival. Subsequently, we found that P4HA3 was strongly associated with the macrophage infiltration level in colon cancer. Immediately we also found that decreasing P4HA3 expression promoted macrophage phagocytosis in colon cancer cells, whereas P4HA3 overexpression produced the opposite effect. Finally, we demonstrated that P4HA3 promoted the expression of cluster of differentiation 47 (CD47) in colon cancer cells. Moreover, P4HA3 caused colon cancer cells to secrete Interleukin 34 (IL34) and Macrophage colony stimulating factor (M-CSF), which further induced macrophages to differentiate to M2 type and thereby contributed to the progression of colon cancer. We have demonstrated that P4HA3-driven CD47 overexpression may act as an escape mechanism, causing colon cancer cells to evade phagocytosis from macrophages.

Hypoxia-induced P4HA1 overexpression promotes post-ischemic angiogenesis by enhancing endothelial glycolysis through downregulating FBP1

BackgroundAngiogenesis is essential for tissue repair in ischemic diseases, relying on glycolysis as its primary energy source. Prolyl 4-hydroxylase subunit alpha 1 (P4HA1), the catalytic subunit of collagen prolyl 4-hydroxylase, is a glycolysis-related gene in cancers. However, its role in glycolysis-induced angiogenesis remains unclear.MethodsP4HA1 expression was modulated using adenoviruses. Endothelial angiogenesis was evaluated through 5-ethynyl-2′-deoxyuridine incorporation, transwell migration, and tube formation assays in vitro. In vivo experiments measured blood flow and capillary density in the hindlimb ischemia (HLI) model. Glycolytic stress assays, glucose uptake, lactate production, and quantitative reverse transcription-polymerase chain reaction (RT-PCR) were employed to assess glycolytic capacity. Transcriptome sequencing, validated by western blotting and RT-PCR, was utilized to determine underlying mechanisms.ResultsP4HA1 was upregulated in endothelial cells under hypoxia and in the HLI model. P4HA1 overexpression promoted angiogenesis in vitro and in vivo, while its knockdown had the opposite effect. P4HA1 overexpression reduced cellular α-ketoglutarate (α-KG) levels by consuming α-KG during collagen hydroxylation. Downregulation of α-KG reduced the protein level of a DNA dioxygenase, ten–eleven translocation 2 (TET2), and its recruitment to the fructose-1,6-biphosphatase (FBP1) promoter, resulting in decreased FBP1 expression. The decrease in FBP1 enhanced glycolytic metabolism, thereby promoting endothelial angiogenesis.ConclusionsHypoxia-induced endothelial P4HA1 overexpression enhanced angiogenesis by promoting glycolytic metabolism reprogramming through the P4HA1/α-KG/TET2/FBP1 pathway. The study’s findings underscore the significance of P4HA1 in post-ischemic angiogenesis, suggesting its therapeutic potential for post-ischemic tissue repair.

FRI670 Osteoblast Rna Sequencing In T1d Mice Reveals Genetic Signature Of Maladaptation To Hypoxia And Compromised Collagen Synthesis

Abstract Disclosure: S. Kim: None. J. Hong: None. F. Sultana: None. E. Shelly: None. F. Korkmaz: None. J. Gimenez: None. T. Yuen: None. I. Daehn: None. J. Choi: None. M. Zaidi: None. The main feature of skeletal abnormality in type 1 diabetes (T1D) is low bone turnover with decreased osteoblastic bone formation [1, 2]. However, the mechanism of osteoblast dysfunction remains unclear. We generated T1D mice using low dose streptozotocin (STZ). T1D mice showed lower bone mass (g/cm2) at the femur (0.07 vs. 0.09*) and trends at lumbar spine (0.05 vs. 0.06, p=0.08) compared with control group at 8 weeks after inducing T1D. Osteoblasts were differentiated using bone marrow mesenchymal stem cells, and RNAseq was performed to analyze the transcriptome of osteoblasts. In gene set enrichment analysis, several pathways including immune, hypoxia, and glycolytic pathway were enriched. The osteogenic genes panel showed decreased Bglap and Col1a1 expression, together with lower expression of Bmp2 and Wnt5a, suggesting decreased bone formation might be related to the suppression of BMP and WNT signaling. Particularly, P4ha2, encoding prolyl 4-hydroxylase subunit alpha–2, which are responsible for posttranslational modification of collagen were downregulated in T1D osteoblasts (log2FC = – 1.7**). Among genes in hypoxia pathway, Egln3 encoding prolyl hydroxylase domain-containing protein 2 and Vhl encoding von Hippel-Lindau tumor suppressor, both of which stabilize HIF–α were downregulated (log2FC = – 2.8** and – 0.31*, respectively) likely for promoting HIF–α dependent gene expression in hypoxia. However, genes of the growth signaling pathway namely Pgf, Vegfa, and Igf1r were downregulated (log2FC = – 3.1**, – 0.4* and – 0.5**, respectively). Altogether, our findings suggest that maladaptation to hypoxic condition in T1D with compromised growth signaling pathway and impaired collagen synthesis might be related to osteoblasts dysfunction in T1D bone. (* p < 0.05 and ** p < 0.001) [1] Shanbhogue VV et al, JBMR. 2015[2] Rubin MR et al, JCEM. 2022 Presentation: Friday, June 16, 2023

Multilevel chitosan-gelatin particles loaded with P4HA1 siRNA suppress glioma development.

It has been reported that prolyl 4-hydroxylase subunit alpha 1 (P4HA1) promoted tumor growth and metastasis of glioma; thus, targeting P4HA1 may be a promising therapeutic strategy against glioma. In consideration of the instability of siRNA in vivo, the chitosan-gelatin microspheres loaded with P4HA1 siRNA (P4HA1 siRNA@CGM) were employed. Firstly, the gel electrophoresis and hemolytic test were performed to assess the stability and blood compatibility of P4HA1 siRNA@CGM. Then, methyl thiazolyl tetrazolium (MTT), cell colony formation, Transwell assay, wound healing assay, gliosphere formation, tube formation, and Western blot were performed to assess the effects of P4HA1 siRNA@CGM on the biological functions of glioma. Finally, 125I-labeled P4HA1 siRNA@CGM was injected into the xenograft mice, radionuclide imaging was recorded, Ki67 and terminal deoxynucleoitidyl transferase-mediated nick end labeling (TUNEL) staining was performed to assess the effects of P4HA1 siRNA@CGM on tumor growth and apoptosis of glioma in vivo. The results showed that P4HA1 siRNA and P4HA1 siRNA@CGM not only markedly inhibited the proliferation, metastasis, gliosphere formation, and the protein levels of interstitial markers (N-cadherin and vimentin) and the transcription factors of epithelial-mesenchymal transition (EMT) (Snail, Slug, and Twist1) in glioma cells, but also inhibited the tube formation in human brain microvascular endothelial cells (HBMECs), and P4HA1 siRNA@CGM exhibited the better inhibitory effects than P4HA1 siRNA. Above results suggested the feasibility of P4HA1 siRNA@CGM in the clinical treatment of glioma.

Prolyl 4-hydroxylase P4HA1 Mediates the Interplay Between Glucose Metabolism and Stemness in Pancreatic Cancer Cells.

Cancer stem cells (CSCs) are profoundly implicated in tumor initiation and progression as well as drug resistance and tumor recurrence of many cancer types, especially pancreatic ductal adenocarcinoma (PDAC). Previously, we revealed that prolyl 4-hydroxylase subunit alpha 1 (P4HA1) enhances the Warburg effect and tumor growth in PDAC. However, the possible connection between P4HA1 and cancer stemness in PDAC remains obscure. In this study, P4HA1-dependent cancer stemness was studied by sphere-formation assay and detection of stemness markers. Glycolytic capacity in cancer stem cells and their parental tumor cells was investigated by glucose uptake, lactate secretion, and expression of glycolytic genes. Glycolysis inhibitors were used to determine the link between cancer stemness and glycolysis. A subcutaneous xenograft model was generated to investigate P4HA1-induced stemness and glycolysis in vivo. We revealed that ectopic expression of P4HA1 increased the stemness of PDAC cells as evidenced by the increased proportion of CD133+ cells, elevated sphere-formation ability, and the upregulated levels of cancer stemness-related proteins (SOX2, OCT4, and NANOG). Blocking tumor glycolysis with 2-Deoxy-D-glucose (2-DG) or a selective inhibitor of glucose transporter 1 (STF-31) significantly reduced the stem properties of PDAC cells, suggesting that P4HA1-induced glycolysis was essential for the stem-like phenotype of PDAC cells. In addition, in vivo study reaffirmed a promotive effect of P4HA1 on tumor glycolysis and cancer stemness. Collectively, our findings suggest that P4HA1 not only affects tumor metabolic reprogramming but also facilitates cancer stemness, which might be exploited as a vulnerable target for PDAC treatment.

Network pharmacological analysis of corosolic acid reveals P4HA2 inhibits hepatocellular carcinoma progression

BackgroundCorosolic acid is a pentacyclic triterpene acid with hypoglycemic, anti-inflammatory, and anti-cancer effects. However, its potential targets in hepatocellular carcinoma (HCC) are unknown, hindering clinical utilization.MethodsDifferentially expressed proteins of the Bel-7404 cell line were identified with tandem mass tag analysis and differentially expressed genes (DEGs) of an HCC TCGA dataset using bioinformatics. Gene functions and pathways were inferred using the DAVID database. Online databases were used to establish P4HA2 expression in HCC (GEPIA2) and its relationship with patient survival (UALCAN and The Human Protein Atlas), the association between P4HA2 expression and immune cell infiltration (TIMER2), and DNA methylation of the P4HA2 gene (MethSurv). Cell proliferation, cell cycle, and cell death were assessed with PI and SYTOX-Green staining, CCK-8, and colony formation assays. Protein expression levels were detected by Western blotting.ResultsA total of 44 differentially expressed proteins and 4498 DEGs were identified. Four genes whose proteins were also found in the differential protein profile but with opposing expressions were selected as candidate targets. The candidate gene prolyl 4-hydroxylase subunit alpha 2 (P4HA2) was recognized as the only potential target due to its high expression in public datasets, association with poor patient survival, and relation to immune cell infiltration in HCC tissues. Moreover, the DNA methylation status in 4 CpG islands of the P4HA2 gene correlated with a poor prognosis. Furthermore, corosolic acid treatment inhibited the proliferation of HCC cell lines Bel-7404 and HepG2 in a dose-dependent manner, caused G2/M phase cell cycle arrest, and promoted cell death. In addition, the treatment reduced P4HA2 protein levels.ConclusionOur results indicate that P4HA2 is a potential target of corosolic acid. Thus, they contribute to understanding molecular changes in HCC after corosolic acid treatment and facilitate finding new treatment regimens.

P4HA1 Promotes Cell Migration and Colonization in Hypopharyngeal Squamous Cell Carcinoma.

This study aimed to identify key molecules associated with the survival of patients with hypopharyngeal squamous cell carcinoma (HpSCC) by combining in silico and in vitro analyses. Differentially expressed genes (DEGs) were screened using the Gene Expression Omnibus database. For DEGs, we performed functional enrichment and protein-protein interaction network analyses to identify potential biological functions and hub genes. Functional analysis of HpSCC cell lines verified the critical roles of the hub genes. DEGs were associated with the extracellular matrix. Among the hub genes, high expression of prolyl 4-hydroxylase subunit alpha 1 (P4HA1) was significantly associated with shorter survival. In addition, P4HA1 knockdown inhibited cell migration and colonization. Suppression of cell proliferation was demonstrated using P4HA1-selective inhibitors. P4HA1 may be a useful therapeutic target for the treatment of HpSCC.

Molecular Characterization and Functional Analysis of Hypoxia-Responsive Factor Prolyl Hydroxylase Domain 2 in Mandarin Fish (Siniperca chuatsi).

With increased breeding density, the phenomenon of hypoxia gradually increases in aquaculture. Hypoxia is primarily mediated by the hypoxia-inducible factor 1 (HIF-1) signaling pathway. Prolyl hydroxylase domain proteins (PHD) are cellular oxygen-sensing molecules that regulate the stability of HIF-1α through hydroxylation. In this study, the characterization of the PHD2 from mandarin fish Siniperca chuatsi (scPHD2) and its roles in the HIF-1 signaling pathway were investigated. Bioinformation analysis showed that scPHD2 had the conserved prolyl 4-hydroxylase alpha subunit homolog domains at its C-terminal and was more closely related to other Perciformes PHD2 than other PHD2. Tissue-distribution results revealed that scphd2 gene was expressed in all tissues tested and more highly expressed in blood and liver than in other tested tissues. Dual-luciferase reporter gene and RT-qPCR assays showed that scPHD2 overexpression could significantly inhibit the HIF-1 signaling pathway. Co-immunoprecipitation analysis showed that scPHD2 could interact with scHIF-1α. Protein degradation experiment results suggested that scPHD2 could promote scHIF-1α degradation through the proteasome degradation pathway. This study advances our understanding of how the HIF-1 signaling pathway is regulated by scPHD2 and will help in understanding the molecular mechanisms underlying hypoxia adaptation in teleost fish.

Characterization of a novel prolyl hydroxylase 2 gene from mud crab Scylla paramamosain: Insights into its role in the regulation of hypoxia-inducible factor-1α

Prolyl hydroxylase 2 (PHD2) is the key oxygen sensor that regulates the stability of the hypoxia-inducible factor -1α (HIF-1α). In this study, a novel PHD2 gene from the mud crab Scylla paramamosain, named SpPHD2, was cloned and identified. The full-length transcript of SpPHD2 was found to be 1926 bp, consisting of a 333 bp 5′ untranslated region, a 1239 bp open reading frame, and a 354 bp 3′ untranslated region. The putative SpPHD2 protein contained a Prolyl 4-hydroxylase alpha subunit homologues (P4Hc) domain in the C-terminal and a Myeloid translocation protein 8, Nervy, and DEAF-1 (MYND)-type zinc finger (zf-MYND) domain in the N-terminal. The mRNA expression of SpPHD2 was found to be widely distributed across all examined tissues. Additionally, the subcellular localization results indicated that the SpPHD2 protein was mainly localized in the cytoplasm. The in vivo silencing of SpPHD2 resulted in the upregulation of SpHIF-1α and a series of downstream genes involved in the HIF-1 pathway, while SpPHD2 overexpression in vitro dose-dependently reduced SpHIF-1α transcriptional activity, indicating that SpPHD2 plays a crucial role in SpHIF-1α regulation. Interestingly, the expression of SpPHD2 increased under hypoxic conditions, which was further inhibited by SpHIF-1α interference. Moreover, four hypoxia response elements were identified in the SpPHD2 promoter, suggesting that a feedback loop exists between SpPHD2 and SpHIF-1α under hypoxia. Taken together, these results provided new insights into the regulation of SpPHD2 in response to hypoxia in S. paramamosain.

Developmental growth plate cartilage formation suppressed by artificial light at night via inhibiting BMAL1-driven collagen hydroxylation.

Exposure to artificial light at night (LAN) can induce obesity, depressive disorder and osteoporosis, but the pernicious effects of excessive LAN exposure on tissue structure are poorly understood. Here, we demonstrated that artificial LAN can impair developmental growth plate cartilage extracellular matrix (ECM) formation and cause endoplasmic reticulum (ER) dilation, which in turn compromises bone formation. Excessive LAN exposure induces downregulation of the core circadian clock protein BMAL1, which leads to collagen accumulation in the ER. Further investigations suggest that BMAL1 is the direct transcriptional activator of prolyl 4-hydroxylase subunit alpha 1 (P4ha1) in chondrocytes, which orchestrates collagen prolyl hydroxylation and secretion. BMAL1 downregulation induced by LAN markedly inhibits proline hydroxylation and transport of collagen from ER to golgi, thereby inducing ER stress in chondrocytes. Restoration of BMAL1/P4HA1 signaling can effectively rescue the dysregulation of cartilage formation within the developmental growth plate induced by artificial LAN exposure. In summary, our investigations suggested that LAN is a significant risk factor in bone growth and development, and a proposed novel strategy targeting enhancement of BMAL1-mediated collagen hydroxylation could be a potential therapeutic approach to facilitate bone growth.

Abstract 1003: The prognostic significance of prolyl 4-hydroxylase subunit alpha 1 and the therapeutic efficacy of diethyl-pythiDC, its small molecule inhibitor, in pancreatic ductal adenocarcinoma

Abstract Background: Prolyl 4-hydroxylase subunit alpha 1 (P4HA1) has an oncogenic role in pancreatic ductal adenocarcinoma (PDAC). Since high expression of P4HA1 in PDAC is suggested to correlate with poor prognosis, targeting P4HA1 could have therapeutic benefits. Herein, we assessed the prognostic significance of P4HA1 expression at the RNA and protein levels in PDAC using publicly available data. We also evaluated the efficacy of diethyl-pythiDC, a small molecule inhibitor of P4HA1, in PDAC cells. Methods: UALCAN (ualcan.path.uab.edu), a comprehensive proteogenomic cancer data analysis portal, was used to obtain gene expression P4HA1 as transcripts per million reads (TPM) (PDAC n=178) from The Cancer Genome Atlas (TCGA); levels of P4HA1 protein expression data were obtained from (normal pancreas, n=74, PDAC n=137) the Clinical Proteomic Tumor Analysis consortium (CPTAC). Immunohistochemical analysis obtained from Human Protein Atlas (HPA) confirmed increased P4HA1 protein expression. Overall survival (OS) between patients with high and low/medium TPM (TPM values above and below upper quartile, respectively) and high and low protein expression score (based on staining intensity and fraction of stained cells) was calculated using the log-rank Wilcoxon test. To determine the efficacy of diethyl-pythiDC in PDAC cells (PANC-1 and BxPC-3), we performed clonogenic assay for colony formation, MTT assay for cell proliferation, flow cytometry for cell cycle analysis, and western blotting for markers of the epithelial-mesenchymal transition (EMT). Results: In the TCGA data, high P4HA1 expression (TPMs) was associated with a poor prognosis (high expression vs. low/medium expression, log-rank p=0.009). Analysis of HPA data showed that the 5-year OS of patients with high P4HA1 expression was 12% vs. 58% for patients with low P4HA1 (log-rank p<0.001). CPTAC data showed higher P4HA1 protein expression in patients with receptor tyrosine kinase (RTK) pathway (p<0.001), mammalian target of rapamycin (mTOR) pathway (p=0.045) and SWItch/Sucrose Non-Fermentable (SWI-SNF) complex (p=0.022) alterations. Diethyl-pythiDC treatment of PDAC cells reduced proliferation, decreased colony formation, and increased G2/M cell cycle arrest. In addition, diethyl-pythiDC increased protein expression of E-cadherin, an epithelial marker, and decreased the expression of N-cadherin and vimentin, the mesenchymal protein markers. Conclusions: Patients with high P4HA1 expression had poor OS. CPTAC data showed higher P4HA1 protein expression in patients with RTK, mTOR and SWI-SNF alterations. Targeting P4HA1 with diethyl-pythiDC reduced proliferation by arresting cells in G2/M phase of the cell cycle and modulated EMT markers. Thus, targeting of P4HA1 can be a viable strategy and may be considered in future PDAC clinical trials. Citation Format: Moh'd Khushman, Farrukh Afaq, Prachi Bajpai, Sameer Al Diffalha, Darryl Outlaw, Grant R. Williams, Rojymon Jacob, Kondal Rao Kyanam Kabir, Ali Ahmed, Peter Shajan, Sooryanarayana Varambally, Upender Manne. The prognostic significance of prolyl 4-hydroxylase subunit alpha 1 and the therapeutic efficacy of diethyl-pythiDC, its small molecule inhibitor, in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1003.

Systematic pan-cancer analysis of the potential tumor diagnosis and prognosis biomarker P4HA3.

Purpose: Prolyl 4-hydroxylase subunit alpha 3 (P4HA3) is implicated in several cancers' development. However, P4HA3 has not been reported in other cancers, and the exact mechanism of action is currently unknown. Materials and methods: First, the expression profile of P4HA3 was analyzed using a combination of the University of California Santa Cruz (UCSC) database, Cancer Cell Line Encyclopedia (CCLE) database, and Genotype-Tissue Expression (GTEx) database. UniCox and Kaplan-Meier were used to analyze the predictive value of P4HA3. The expression of P4HA3 was analyzed in clinical staging, immune subtypes, and Molecular subtypes. Secondly, the correlation of P4HA3 with immunomodulatory genes, immune checkpoint genes, RNA modification genes, immune cell infiltration, cancer-related functional status, tumor stemness index, DNA mismatch repair (MMR) genes and DNA Methyltransferase was examined. The role of P4HA3 in DNA methylation, copy number variation (CNV), mutational status, tumor mutational burden (TMB), and microsatellite instability (MSI) was also analyzed. In addition, gene set enrichment analysis (GSEA) was used to explore the potential functional mechanisms of P4HA3 in pan-cancer. Finally, P4HA3-related drugs were searched in CellMiner, Genomics of Drug Sensitivity in Cancer (GDSC), and Cancer Therapeutics Response Portal (CTRP) databases. Results: P4HA3 is significantly overexpressed in most cancers and is associated with poor prognosis. P4HA3 is strongly associated with clinical cancer stage, immune subtypes, molecular subtypes, immune regulatory genes, immune checkpoint genes, RNA modifier genes, immune cell infiltration, cancer-related functional status, tumor stemness index, MMR Gene, DNA Methyltransferase, DNA methylation, CNV, mutational status, TMB, and MSI are closely related. Available enrichment analysis revealed that P4HA3 is associated with the epithelial-mesenchymal transition and immune-related pathways. There are currently 20 drugs associated with P4HA3. Conclusion: In human pan-cancer, P4HA3 is associated with poor patient prognosis and multiple immune cells and may be a novel immunotherapeutic target. It may act on tumor progression through the epithelial-mesenchymal transition (EMT) pathway.

CEBPB upregulates P4HA2 to promote the malignant biological behavior in IDH1 wildtype glioma.

Temozolomide (TMZ), the primary drug for glioma treatment, has limited treatment efficacy. Additionally, considerable evidence shows that isocitrate dehydrogenase 1 mutation-type (IDH1 mut) gliomas have a better response to TMZ than isocitrate dehydrogenase 1 wildtype (IDH1 wt) gliomas. Here, we aimed to identify potential mechanisms underlying this phenotype. Herein, the Cancer Genome Atlas bioinformatic data and 30 clinical samples from patients were analyzed to reveal the expression level of cytosine-cytosine-adenosine-adenosine-thymidine (CCAAT) Enhancer Binding Protein Beta (CEBPB) and prolyl 4-hydroxylase subunit alpha 2 (P4HA2) in gliomas. Next, cellular and animal experiments, including cell proliferation, colony formation, transwell, CCK-8, and xenograft assays, were performed to explore the tumor-promoting effects of P4HA2 and CEBPB. Then, chromatin immunoprecipitation (ChIP) assays were used to confirm the regulatory relationships between them. Finally, a co-immunoprecipitation (Co-IP) assay was performed to confirm the effect of IDH1-132H to CEBPB proteins. We found that CEBPB and P4HA2 expression was significantly upregulated in IDH1 wt gliomas and associated with poor prognosis. CEBPB knockdown inhibited the proliferation, migration, invasion, and temozolomide resistance of glioma cells and hindered the growth of glioma xenograft tumors. CEBPE, as a transcription factor, exerted its function by transcriptionally upregulating P4HA2 expression in glioma cells. Importantly, CEBPB is prone to ubiquitin-proteasomal degradation in IDH1 R132H glioma cells. We also demonstrated that both genes are related to collagen synthesis, as confirmed by in vivo experiments. Thus, CEBPE promotes proliferation and TMZ resistance by inducing P4HA2 expression in glioma cells and offers a potential therapeutic target for glioma treatment.

Thrombospondin-1 and prolyl 4-hydroxylase subunit alpha 3 as potential biomarkers of salivary gland fibrosis

Background/purposeFibrosis is present in various physiologic and pathologic conditions of salivary glands (SGs). This study aimed to identify novel biomarkers of SG fibrosis by next-generation sequencing. Materials and methodsWe established the SG fibrosis mouse model by excretory main duct ligation. Next-generation sequencing, differentially expressed gene (DEG) analysis, and gene set enrichment analysis was performed by comparing ligated and control SGs. We used algorithms of Cytohubba, molecular complex detection, Lasso logistic regression, and support vector machine to identify the key biomarkers. Selected key biomarkers were verified by the polymerase chain reaction and immunohistochemistry. We also retrieved and analyzed the key gene expression in the fibrosis of the heart, liver, lung, and kidney to ensure the generalization of key biomarkers in SG fibrosis. ResultsBoth interlobular and intralobular fibrosis was confirmed in the ligated SGs, with improved expressions of collagen I and transforming growth factor β. Next-generation sequencing identified 2666 upregulated DEGs and 336 downregulated DEGs, which were highly enriched in the extracellular matrix-related pathways. Multiple algorithms identified 15 key biomarkers in SG fibrosis, including Thrombospondin-1 (THBS1) and Prolyl 4-Hydroxylase Subunit Alpha 3 (P4HA3). The mRNA and protein expression of THBS1 and P4HA3 was verified in mice. THBS1 was also highly expressed in lung and kidney fibrosis, whereas P4HA3 was upregulated in liver fibrosis. ConclusionTHBS1 and P4HA3 may be potential biomarkers for SG fibrosis. They may be also applicable in the diagnosis of multi-organ fibrosis.

High Prolyl 4-Hydroxylase Subunit Alpha 3 Expression as an Independent Prognostic Biomarker and Correlated With Immune Infiltration in Gastric Cancer.

Background: Gastric cancer (GC) has a high mortality rate and is particularly prevalent in China. The extracellular matrix protein, prolyl 4-hydroxylase subunit alpha 3 (P4HA3), has been implicated in various cancers. We aimed to assess the diagnostic and prognostic value of P4HA3 in GC and investigate its correlation with immune cell infiltration. Methods: The present study used microarray data from the Cancer Genome Atlas (TCGA) to analyze the association of P4HA3 expression with clinicopathological features. Data from the Gene Expression Omnibus (GEO) were used for validation. Receiver operating characteristic (ROC) and Kaplan–Meier curves were constructed to determine the diagnostic and prognostic value of P4HA3 in GC. Univariate and multivariate regression analyses were performed to assess the impact of P4HA3 on overall survival (OS) rates. A protein–protein interaction (PPI) network was generated and functional enrichment evaluated. Single-sample gene set enrichment analysis (ssGSEA) was conducted to correlate P4HA3 expression with immune cell infiltration. The correlation between P4HA3 and immune check point genes was studied. Results: P4HA3 was over-expressed in GC, along with 15 other types of cancer, including breast invasive carcinoma and cholangiocarcinoma. P4HA3 showed high diagnostic and prognostic value in GC and was an independent prognostic factor. P4HA3, TNM (tumor, node, metastases) stage, pathological stage and age all correlated with OS rates. Genes related to P4HA3 were enriched in the lumen of the endoplasmic reticulum and included procollagen-proline 3-dioxygenase activity. P4HA3 expression correlated with numbers of macrophages, natural killer (NK) cells, immature dendritic cells (iDC), mast cells, eosinophils, effective memory T cells (Tem), T-helper 1 (Th1) cells and dendritic cells (DC). P4HA3 was positively correlated with hepatitis A virus cellular receptor 2 (HAVCR2) and programmed cell death 1 ligand 2 (PDCD1LG2). Conclusion: P4HA3 is a potential independent biomarker for prognosis of GC and may be an immunotherapy target in the treatment of GC.

The Role of P4HA1 in Multiple Cancer Types and its Potential as a Target in Renal Cell Carcinoma.

Background: Prolyl 4-hydroxylase subunit alpha 1 (P4HA1) provides the majority of the catalytic site of the active P4H enzyme. Emerging evidence has revealed that P4HA1 participates in the initiation and development of several malignant tumors. However, a pan-cancer analysis of P4HA1 has not been performed. Methods: In this study, we carried out an in-depth analysis of the expression patterns and prognostic value of P4HA1 using the datasets of The Cancer Genome Atlas (TCGA) and Kaplan–Meier Plotter. Genomic and epigenetic alterations of P4HA1 and the correlation of P4HA1 with DNA methylation in different cancers were also analyzed across multiple databases. In addition, the purity-adjusted partial Spearman’s correlation test was utilized to evaluate the correlation between P4HA1 expression and immune cell infiltration. We also further explored the biological function and mechanism of P4HA1 in renal cell carcinoma (RCC). Results: We characterized the expression profiles and prognostic values of P4HA1 in multiple cancer types. P4HA1 expression was increased in clear cell renal cell carcinoma (RCC) compared to adjacent normal tissues, and P4HA1 positively correlated with the overall survival (OS) and disease-free survival (DFS) in papillary RCC. In addition, a positive correlation between P4HA1 expression and immune cell infiltration was observed in clear cell RCC. We also identified a strong correlation between P4HA1 expression and immune checkpoint gene expression, microsatellite instability, and tumor mutation burden in chromophobe RCC. Finally, the results of in vitro experiments verified that overexpression of P4HA1 promoted the proliferation, migration, invasion, and epithelial–mesenchymal transition of RCC cells. Conclusion: Overall, our study has suggested that P4HA1 might play a significant role in tumorigenesis in RCC and may be a prognostic biomarker and therapeutic target for several malignant tumors, including RCC.

MiR-1266-3p Suppresses Epithelial-Mesenchymal Transition in Colon Cancer by Targeting P4HA3.

Numerous studies have been conducted to demonstrate that miRNA is strongly related to colon cancer progression. Nevertheless, there are few studies regarding the function for miR-1266-3p in colon cancer, and the molecular mechanism remains poorly know. Our study was designed to examine the level of miR-1266-3p expression among the colon cancer tissue and cell and to study the role and regulatory mechanism for miR-1266-3p among colon cancer's malignant biologic behavior. First, we found that miR-1266-3p expression was distinctly lower in colonic carcinoma tissues and cells than in nontumor ones, and the prognosis of low miR-1266-3p patients was distinctly worse than that of high miR-1266-3p patients. Second, we predicted that the target gene of miR-1266-3p was prolyl 4-hydroxylase subunit alpha 3 (P4HA3) through bioinformatics, and the targeting relationship between the two was verified by a dual luciferase assay report. Furthermore, miR-1266-3p inhibited the growth and metastasis of colon cancer in vitro as well as in vivo, and this effect could be alleviated by overexpressing P4HA3. Even more importantly, our study demonstrated that miR-1266-3p inhibited epithelial-mesenchymal transition (EMT) by targeting P4HA3. In conclusion, miR-1266-3p could inhibit growth, metastasis, and EMT in colon cancer by targeting P4HA3. Our discoveries might offer a novel target for colon cancer diagnosis and treatment.