Circulating hypoxia marker carbonic anhydrase IX (CA9) in patients with hepatocellular carcinoma and patients with cirrhosis

The effect of baseline O2 conditions on the response of prostate cancer cells to hypoxia

The transcriptional response to hypoxia is largely regulated by the hypoxia-inducible factors (HIFs), which induce the expression of genes involved in glycolysis, angiogenesis, proliferation, and migration. Virtually all cell culture-based hypoxia experiments have used near-atmospheric (18% O2) oxygen levels as the baseline for comparison with hypoxia. However, this is hyperoxic compared with mammalian tissue microenvironments, where oxygen levels range from 2% to 9% O2 (physioxia). Thus, these experiments actually compare hyperoxia to hypoxia. To determine how the baseline O2 level affects the subsequent response to hypoxia, we cultured PC-3 prostate cancer cells in either 18% or 5% O2 for 2 wk before exposing them to hypoxia (∼1.1% pericellular O2) for 12-48 h. RNA-seq revealed that the transcriptional response to hypoxia was dependent on the baseline O2 level. Cells grown in 18% O2 before hypoxia exposure showed an enhanced induction of HIF targets, particularly genes involved in glucose metabolism, compared with cells grown in physioxia before hypoxia. Consistent with this, hypoxia significantly increased glucose consumption and metabolic activity only in cells previously cultured in 18% O2, but not in cells preadapted to 5% O2. Transcriptomic analyses also indicated effects on cell proliferation and motility, which were followed up by functional assays. Although unaffected by hypoxia, both proliferation and migration rates were greater in cells cultured in 5% O2 versus 18% O2. We conclude that an inappropriately hyperoxic starting condition affects the transcriptional and metabolic responses of PC-3 cells to hypoxia, which may compromise experiments on cancer metabolism in vitro.NEW & NOTEWORTHY Although human cell culture models have been instrumental to our understanding of the mechanisms involved in the cellular response to hypoxia, in virtually all experiments, cells are routinely cultured in near-atmospheric (∼18% O2) oxygen levels, which are hyperoxic relative to physiological conditions in vivo. Here, we show for the first time that cells cultured in physiological O2 levels (5% O2) respond differently to subsequent hypoxia than cells grown at 18%.

Investigating the molecular mechanism of Qizhu anticancer prescription in inhibiting hepatocellular carcinoma based on high-resolution mass spectrometry and network pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Of all primary liver cancer cases, hepatocellular carcinoma (HCC) accounts for about 90%. Most patients with HCC receive a diagnosis in the medium-to-late stages or with chronic liver disease, have lost the opportunity for radical treatment, such as surgical resection, and their 5-year survival rate is low. Qizhu Anticancer Prescription (QZACP) is an empirical formula composed of traditional Chinese herbs that can clinically relieve HCC symptoms, inhibit the progression of HCC, reduce recurrence rate, and prolong survival; however, its exact mode of action remains unknown.

AIM OF THE STUDY

This study's purpose was to investigate the mode of action of QZACP in the prevention and treatment of HCC.

MATERIALS AND METHODS

Initially, drug components in the QZACP decoction were analyzed using high-resolution mass spectrometry. A subcutaneous tumor xenograft model in nude mice was constructed to further analyze the active components of QZACP that had entered tumor tissues through oral administration. Potential targets of QZACP in the prevention and treatment of HCC were identified and then confirmed in vivo via network pharmacology and molecular docking. In addition, regulatory effects of QZACP on HCC cell proliferation and the cell cycle were detected using a CCK-8 assay and flow cytometry.

RESULTS

High-resolution mass spectrometry revealed that the QZACP decoction contained deacetyl asperulosidic acid methyl ester (DAAME), paeoniflorin, calycosin-7-glucoside, liquiritin, glycyrrhizic acid, astragaloside IV, saikosaponin A, curdione, and atractylenolide II. In nude mice, QZACP could effectively inhibit the growth of subcutaneous tumors, where DAAME, paeoniflorin, liquiritin, and glycyrrhizic acid could enter liver cancer tissues after oral administration. Among these, DAAME was the most highly expressed in HCC tissues and may be an important active component of QZACP for inhibiting HCC. Utilizing network pharmacology, the targets of action of these four drug components were identified. After verification using western blotting, STAT3, VEGFA, JUN, FGF2, BCL2L1, AR, TERT, MMP7, MMP1, ABCB1, CA9, and ESR2 were identified as targets of QZACP inhibition in HCC. In vitro experiments revealed that QZACP inhibited the proliferation of HCC cells while inducing G0/G1 phase cell cycle arrest. In vivo experiments demonstrated that DAAME significantly inhibited HCC growth. After intersection of the 24 DAAME targets predicted using network pharmacology with the 435 HCC disease targets, only CA9 was identified as a DAAME-HCC crossover target. Molecular docking results revealed that the binding site of DAAME and CA9 had good stereo-complementarity with a docking score of -8.1 kcal/mol. Western blotting and immunohistochemical results also confirmed that DAAME significantly decreased CA9 protein expression in HCC.

CONCLUSIONS

QZACP inhibits HCC by reducing the expression of STAT3, VEGFA, JUN, FGF2, BCL2L1, AR, TERT, MMP7, MMP1, ABCB1, CA9, and ESR2. DAAME may be an important active component of QZACP for the prevention and treatment of HCC, inhibiting it by targeting the expression of CA9.

Aerobic vaginitis is associated with carbonic anhydrase IX in cervical intraepithelial neoplasia

The aim of this study was to analyze the association between vaginal microbiota, carbonic anhydrase IX (CAIX) and histological findings of cervical intraepithelial neoplasia (CIN). The study included 132 females, among them 66 were diagnosed with high-grade intraepithelial lesion (CIN2, CIN3, and cancer), 14 with low-grade disease, and 52 assigned to the control group. An interview focused on the behavior risk factors, together with vaginal fluid pH measurement, wet mount microscopy, detection of Chlamydia trachomatis, and Trichomonas vaginalis were performed. After colposcopy, high-grade abnormalities were detected via direct biopsies and treated with conization procedure. Conuses were immuno-stained with CAIX antibody. The histological findings were CIN1 (n = 14), and CIN2+ (included CIN2 (n = 10), CIN3 (n = 49), and cancer (n = 7; squamous cell carcinomas)). Prevalence of bacterial vaginosis (BV) was similar between the groups. Moderate or severe aerobic vaginitis (msAV) was diagnosed more often among CIN2+ (53.0%) than CIN1 (21.4%). Moderate or strong immunostaining of CAIX (msCAIX) was not detected among CIN1 cases. Thus, msAV was prevalent in CAIX non-stained group (p = 0.049) among CIN2 patients. Co-location of msAV and msCAIX was found in CIN3. Regression model revealed that msAV associated with high-grade cervical intraepithelial neoplasia independently from smoking and the number of partners.

Association between glycolysis markers and prognosis of liver cancer: a systematic review and meta-analysis

BACKGROUND

In recent years, the capacity of tumor cells to maintain high levels of glycolysis, even in the presence of oxygen, has emerged as one of the main metabolic traits and garnered considerable attention. The purpose of this meta-analysis is to investigate the prognostic value of glycolysis markers in liver cancer.

METHODS

PubMed, Embase, and Cochrane Library databases were searched for articles on glycolytic marker expression levels associated with the prognosis of liver cancer until April 2023. Stata SE14.0 was used to calculate the aggregate hazard ratios and 95% confidence intervals.

RESULTS

Thirty-five studies were included. The worse overall survival (OS) (P < 0.001), disease-free survival (DFS) (P = 0.001), recurrence-free survival (RFS) (P = 0.004), and time to recurrence (TTR) (P < 0.001) were significantly associated with elevated expression of glycolysis markers. Higher expression of PKM2 (P < 0.001), STMN1 (P = 0.002), MCT4 (P < 0.001), GLUT1 (P = 0.025), HK-2 (P < 0.001), and CA9 (P < 0.001) were significantly related to shorter OS. Increased levels of PKM2 (P < 0.001), CA9 (P = 0.005), and MCT4 (P < 0.001) were associated with worse DFS. Elevated PKM2 expression (P = 0.002) was also associated with poorer RFS in hepatocellular carcinoma patients. GLUT2 expression was not correlated with the prognosis of liver cancer (P = 0.134).

CONCLUSIONS

Elevated expression of glycolysis markers was associated with worse OS, DFS, RFS, and TTR in patients with liver cancer. Therefore, these glycolysis markers could serve as potential prognostic markers and therapeutic targets in liver cancer.

TRIAL REGISTRATION

PROSPERO registration: CRD42023469645.

Hypoxia Marker Carbonic Anhydrase IX Is Present in Abdominal Aortic Aneurysm Tissue and Plasma

Abdominal aortic aneurysms (AAA) are a significant cause of premature deaths worldwide. Since there is no specific treatment for reducing AAA progression, it is crucial to understand the pathogenesis leading to aneurysm wall weakening/remodeling and identify new proteins involved in this process which could subsequently serve as novel therapeutic targets. In this study, we analyzed the presence of the hypoxia-related proteins carbonic anhydrase IX (CA IX), hypoxia-inducible factor 1α (HIF-1α), and AKT as the key molecule in the phosphoinositide-3-kinase pathway in the AAA wall. Additionally, we used a blood-based assay to examine soluble CA IX (s-CA IX) levels in the plasma of AAA patients. Using western blotting, we detected CA IX protein in 12 out of 15 AAA tissue samples. Immunohistochemistry staining proved CA IX expression in the media of the aneurysmal wall. Evaluation of phosphorylated (p-AKT) and total AKT showed elevated levels of both forms in AAA compared to normal aorta. Using ELISA, we determined the concentration of s-CA IX >20 pg/mL in 13 out of 15 AAA patients. Results obtained from in silico analysis of CA9 and aneurysm-associated genes suggest a role for CA IX in aneurysmal wall remodeling. Our results prove the presence of hypoxia-related CA IX in AAA tissues and indicate a possible role of CA IX in hypoxia-associated cardiovascular diseases.

Repression of protocadherin 17 is correlated with elevated angiogenesis and hypoxia markers in female patients with breast cancer

BACKGROUND

Altered cadherin expression plays a vital role in tumorigenesis, angiogenesis and tumor progression. However, the function of protocadherin 17 (PCDH17) in breast cancer remains unclear.

OBJECTIVE

Our target is to explore PCDH17 gene expression in breast carcinoma tissues and its relation to serum angiopoietin-2 (Ang-2), carbonic anhydrase IX (CAIX) and % of circulating CD34+ cells in breast cancer patients (BCPs).

METHODS

This study included Fifty female BCPs and 50 healthy females as control group. Cancerous and neighboring normal breast tissues were collected from BCPs as well as blood samples at diagnosis. PCDH17 gene expression was evaluated by RT-PCR. Serum Ang-2, CAIX levels were measured by ELISA and % CD34+ cells were assessed by flow cytometry.

RESULTS

PCDH17 was downregulated in cancerous breast tissues and its repression was significantly correlated with advanced stage and larger tumor size. Low PCDH17 was significantly correlated with serum Ang-2, % CD34+ cells and serum CAIX levels. Serum CAIX, Ang-2 and % CD34+ cells levels were highly elevated in BCPs and significantly correlated with clinical stage.

CONCLUSIONS

PCDH17 downregulation correlated significantly with increased angiogenic and hypoxia biomarkers. These results explore the role of PCDH17 as a tumor suppressor gene inhibiting tumor growth and proliferation.

Carbonic anhydrase IX as a novel candidate in liquid biopsy

Among the diagnostic techniques for the identification of tumour biomarkers, the liquid biopsy is considered one that offers future research on precision diagnosis and treatment of tumours in a non-invasive manner. The approach consists of isolating tumor-derived components, such as circulating tumour cells (CTC), tumour cell-free DNA (ctDNA), and extracellular vesicles (EVs), from the patient peripheral blood fluids. These elements constitute a source of genomic and proteomic information for cancer treatment. Within the tumour-derived components of the body fluids, the enzyme indicated with the acronym CA IX and belonging to the superfamily of carbonic anhydrases (CA, EC 4.2.1.1) is a promising aspirant for checking tumours. CA IX is a transmembrane-CA isoform that is strongly overexpressed in many cancers being not much diffused in healthy tissues except the gastrointestinal tract. Here, it is summarised the role of CA IX as tumour-associated protein and its putative relationship in liquid biopsyfor diagnosing and monitoring cancer progression.

A Molecular Subtype Model for Liver HBV-Related Hepatocellular Carcinoma Patients Based on Immune-Related Genes

Hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) is one of the most common malignant tumors in the world with a very poor prognosis. Immunotyping is of great significance for predicting HCC outcomes and guiding immunotherapy. Therefore, we sought to establish a reliable prognostic model for HBV-related HCC based on immune scores. We identified immune-related modules of The Cancer Genome Atlas LIHC and GSE14520 data sets through weighted gene co-expression network analysis and evaluated HCC through a non-negative matrix factorization algorithm. Through further bioinformatics analyses, we identified causes for prognostic differences between subtypes. The results illustrate a significant difference in prognosis based on immunotypes, which may stem from metabolic disorders and increased tumor invasion associated with the high expression of genes related to stem cell characteristics. In conclusion, we identified a novel HBV-related HCC immune subtype and determined its immunological characteristics, which provides ideas for further individualized immunotherapy research.

ROC-1, P21 and CAIX as markers of tumor aggressiveness in bladder carcinoma in Egyptian patients

BACKGROUND

Bladder cancer (BC) is one of the most common malignancies in Egypt, representing about 8.7% of cancers in both sexes with more predominance in males, making identification of valuable predictive and prognostic markers, mandatory. Cullin-RING ligases (CRL) play an important role in the ubiquitination of cell cycle-related proteins or other proteins (e.g., DNA replication protein, signal transduction protein). Regulator of Cullins-1 (ROC-1) is a key subunit of CRL. P21 belongs to the family of cyclin dependent kinase inhibitors (CKIs) which regulates cell cycle by inactivating Cyclin- Dependent Kinases key regulators of the cell cycle. CAIX a highly active member of the family of carbonic anhydrases has gained much interest as a hypoxic marker. Hypoxia is a consequence of the rapid growth of many tumors, including bladder cancer, and is an important regulator of gene expression and resistance to chemotherapy and radiotherapy. Therefore the purpose of this study is to evaluate the role of ROC-1, CAIX and P21 and its relationship with the clinico-pathological features of bladder cancer in Egyptian patients.

METHODS

Using the standard immunohistochemical technique, ROC-1, CAIX and P21 expression in 80 primary bladder carcinomas and 15 normal bladder specimens as control group were assessed. The bladder carcinoma cases included 50 cases with muscle invasive bladder cancer and 30 cases with non-muscle invasive bladder cancer.

RESULTS

Over expression of ROC-1, CAIX and P21 in BC were significantly associated with muscularis propria invasion and high grade BC. ROC-1, CAIX and P21, showed significant inverse relationship in primary BC cases. CAIX expression was significantly higher in BC compared with controls. Regarding the survival analysis, expression of ROC-1, CAIX and P21 didn't affect the survival of BC patients.

CONCLUSIONS

High expression of ROC-1, CAIX and P21 could be promising potential biomarkers for identifying patients with poor prognostic factors in bladder cancer serving as potential targets for cancer therapy.

Microsecond Simulation of the Proteoglycan-like Region of Carbonic Anhydrase IX and Design of Chemical Inhibitors Targeting pH Homeostasis in Cancer Cells

Carbonic anhydrase IX (CAIX) is a membrane-bound enzyme associated with tumor hypoxia and found to be over expressed in various tumor conditions. Targeting CAIX catalytic activity is proven to be efficient modality in modulating pH homeostasis in cancer cells. Proteoglycan-like (PG) region is unique to CAIX and is proposed to serve as an antenna enhancing the export of protons in conjunction with facilitated efflux of lactate ions via monocarboxylate transporters. Moreover, the PG region is also reported to contribute to the assembly and maturation of focal adhesion links during cellular attachment and dispersion on solid supports. Thus, drug targeting of this region shall efficiently modulate pH homeostasis and cell adhesion in cancer cells. As the PG region is intrinsically disordered, the complete crystal structure is not elucidated. Hence, in this study, we intend to sample the conformational landscape of the PG region at microsecond scale simulation in order to sample the most probable conformations that shall be utilized for structure-based drug design. In addition, the sampled conformations were subjected to high-throughput virtual screening against NCI and Maybridge datasets to identify potential hits based on consensus scoring and validation by molecular dynamics simulation. Further, the identified hits were experimentally validated for efficacy by in vitro and direct enzymatic assays. The results reveal 5-(2-aminoethyl)-1,2,3-benzenetriol to be the most promising hit as it showed significant CAIX inhibition at all levels of in silico and experimental validation.

The Fundamental Role of Bicarbonate Transporters and Associated Carbonic Anhydrase Enzymes in Maintaining Ion and pH Homeostasis in Non-Secretory Organs

The bicarbonate ion has a fundamental role in vital systems. Impaired bicarbonate transport leads to various diseases, including immune disorders, cystic fibrosis, tumorigenesis, kidney diseases, brain dysfunction, tooth fracture, ischemic reperfusion injury, hypertension, impaired reproductive system, and systemic acidosis. Carbonic anhydrases are involved in the mechanism of bicarbonate movement and consist of complex of bicarbonate transport systems including bicarbonate transporters. This review focused on the convergent regulation of ion homeostasis through various ion transporters including bicarbonate transporters, their regulatory enzymes, such as carbonic anhydrases, pH regulatory role, and the expression pattern of ion transporters in non-secretory systems throughout the body. Understanding the correlation between these systems will be helpful in order to obtain new insights and design potential therapeutic strategies for the treatment of pH-related disorders. In this review, we have discussed the broad prospects and challenges that remain in elucidation of bicarbonate-transport-related biological and developmental systems.

Identification of a Subtype of Hepatocellular Carcinoma with Poor Prognosis Based on Expression of Genes within the Glucose Metabolic Pathway

Hepatocellular carcinoma (HCC) is the most prevalent primary cancer and a highly aggressive liver malignancy. Liver cancer cells reprogram their metabolism to meet their needs for rapid proliferation and tumor growth. In the present study, we investigated the alterations in the expression of the genes involved in glucose metabolic pathways as well as their association with the clinical stage and survival of HCC patients. We found that the expressions of around 30% of genes involved in the glucose metabolic pathway are consistently dysregulated with a predominant down-regulation in HCC tumors. Moreover, the differentially expressed genes are associated with an advanced clinical stage and a poor prognosis. More importantly, unsupervised clustering analysis with the differentially expressed genes that were also associated with overall survival (OS) revealed a subgroup of patients with a worse prognosis including reduced OS, disease specific survival, and recurrence-free survival. This aggressive subtype had significantly increased expression of stemness-related genes and down-regulated metabolic genes, as well as increased immune infiltrates that contribute to a poor prognosis. Collectively, this integrative study indicates that expressions of the glucose metabolic genes could be used as potential prognostic markers and/or therapeutic targets, which might be helpful in developing precise treatment for patients with HCC.

Hepatic Tumor Microenvironments and Effects on NK Cell Phenotype and Function

The liver is a complex organ with critical physiological functions including metabolism, glucose storage, and drug detoxification. Its unique immune profile with large numbers of cytotoxic CD8+ T cells and significant innate lymphoid population, including natural killer cells, γ δ T cells, MAIT cells, and iNKTcells, suggests an important anti-tumor surveillance role. Despite significant immune surveillance in the liver, in particular large NK cell populations, hepatic cell carcinoma (HCC) is a relatively common outcome of chronic liver infection or inflammation. The liver is also the second most common site of metastatic disease. This discordance suggests immune suppression by the environments of primary and secondary liver cancers. Classic tumor microenvironments (TME) are poorly perfused, leading to accumulation of tumor cell metabolites, diminished O2, and decreased nutrient levels, all of which impact immune cell phenotype and function. Here, we focus on changes in the liver microenvironment associated with tumor presence and how they affect NK function and phenotype.

Poor outcome in hypoxic endometrial carcinoma is related to vascular density

Background

Identification of endometrial carcinoma (EC) patients at high risk of recurrence is lacking. In this study, the prognostic role of hypoxia and angiogenesis was investigated in EC patients.

Methods

Tumour slides from EC patients were stained by immunofluorescence for carbonic anhydrase IX (CAIX) as hypoxic marker and CD34 for assessment of microvessel density (MVD). CAIX expression was determined in epithelial tumour cells, with a cut-off of 1%. MVD was assessed according to the Weidner method. Correlations with disease-specific survival (DSS), disease-free survival (DFS) and distant disease-free survival (DDFS) were calculated using Kaplan–Meier curves and Cox regression analysis.

Results

Sixty-three (16.4%) of 385 ECs showed positive CAIX expression with high vascular density. These ECs had a reduced DSS compared to tumours with either hypoxia or high vascular density (log-rank p = 0.002). Multivariable analysis showed that hypoxic tumours with high vascular density had a reduced DSS (hazard ratio [HR] 3.71, p = 0.002), DDFS (HR 2.68, p = 0.009) and a trend for reduced DFS (HR 1.87, p = 0.054).

Conclusions

This study has shown that adverse outcome in hypoxic ECs is seen in the presence of high vascular density, suggesting an important role of angiogenesis in the metastatic process of hypoxic EC. Differential adjuvant treatment might be indicated for these patients.