Carbonic anhydrase IX-based tumor imaging and therapy: a review / 生物工程学报

Carbonic anhydrase IX (CAIX) is a transmembrane protein that is specifically overexpressed on the surface of hypoxic tumor cells. With the function of regulating the acidity of tumor cells both inside and outside, CAIX is closely related to tumor proliferation, invasion and metastasis. Therefore, CAIX is a promising target for tumor imaging and therapy. Herein, we summarized recent advances in CAIX-based tumor imaging, therapy and theranostics, and prospected future applications of using CAIX as an anti-tumor target.

miR-7/TGF-β2 axis sustains acidic tumor microenvironment-induced lung cancer metastasis

Acidosis, regardless of hypoxia involvement, is recognized as a chronic and harsh tumor microenvironment (TME) that educates malignant cells to thrive and metastasize. Although overwhelming evidence supports an acidic environment as a driver or ubiquitous hallmark of cancer progression, the unrevealed core mechanisms underlying the direct effect of acidification on tumorigenesis have hindered the discovery of novel therapeutic targets and clinical therapy. Here, chemical-induced and transgenic mouse models for colon, liver and lung cancer were established, respectively. miR-7 and TGF-β2 expressions were examined in clinical tissues (n = 184). RNA-seq, miRNA-seq, proteomics, biosynthesis analyses and functional studies were performed to validate the mechanisms involved in the acidic TME-induced lung cancer metastasis. Our data show that lung cancer is sensitive to the increased acidification of TME, and acidic TME-induced lung cancer metastasis via inhibition of miR-7-5p. TGF-β2 is a direct target of miR-7-5p. The reduced expression of miR-7-5p subsequently increases the expression of TGF-β2 which enhances the metastatic potential of the lung cancer. Indeed, overexpression of miR-7-5p reduces the acidic pH-enhanced lung cancer metastasis. Furthermore, the human lung tumor samples also show a reduced miR-7-5p expression but an elevated level of activated TGF-β2; the expressions of both miR-7-5p and TGF-β2 are correlated with patients' survival. We are the first to identify the role of the miR-7/TGF-β2 axis in acidic pH-enhanced lung cancer metastasis. Our study not only delineates how acidification directly affects tumorigenesis, but also suggests miR-7 is a novel reliable biomarker for acidic TME and a novel therapeutic target for non-small cell lung cancer (NSCLC) treatment. Our study opens an avenue to explore the pH-sensitive subcellular components as novel therapeutic targets for cancer treatment.

Carbonic anhydrase IX immunohistochemistry has potential to predict renal cell carcinoma outcomes: A systematic review and meta-analyses

@#Introduction: Tissue biomarker carbonic anhydrase IX (CAIX) is purported to have prognostic value for renal cell carcinoma (RCC) but contradicting findings from previous studies have also been documented. This study aims to perform a systematic review and meta-analysis on the role of CAIX in RCC disease progression. Materials and Methods: Following the preferred reporting items for systematic review and meta-analysis (PRISMA) guidelines, online searches of multiple databases were performed to retrieve articles from their inception until December 2017. Inclusion criteria included all English-based original articles of immunohistochemistry (IHC) studies investigating CAIX expression in human RCC tissue. Four articles were finally selected for meta-analysis with a total of 1964 patients. Standard meta-analysis methods were applied to evaluate the role of CAIX in RCC prognosis. The relative risk (RR) and its 95% confidence interval (CI) were recorded for the association between biomarker and prognosis, and data were analysed using MedCalc statistical software. Results: The meta-analysis showed that high CAIX expression was associated with low tumour stage (RR 0.90%, 95% CI 0.849-0.969, p= 0.004), low tumour grade (RR 0.835%, 95% CI 0.732-0.983, p= 0.028), absence of nodal involvement (RR 0.814%, 95% CI 0.712-0.931, p= 0.003) and better ECOS-PS index (RR 0.888%, 95% CI 0.818-0.969, p= 0.007). The high tissue CAIX expression in RCC is hence an indication of an early malignancy with a potential to predict favourable disease progression and outcome. Conclusion: The measurement of this marker may be beneficial to determine the course of the illness. It is hoped that CAIX can be developed as a specific tissue biomarker for RCC in the near future

Different expression patterns of carbonic anhydrase IX in oral lichen planus and leukoplakia

Tumor hypoxia is an important indicator of cancer prognosis. Among the different genes that are upregulated by hypoxia is carbonic anhydrase IX, which combines carbon dioxide and water to form bicarbonate and hydrogen. Although expression of this enzyme is very low in normal tissues, carbonic anhydrase IX is overexpressed in several types of cancer. The aim of the present work was to analyze carbonic anhydrase IX expression in the two most frequent potentially malignant oral disorders: oral lichen planus and oral leukoplakia. Immunohistochemical analysis of oral lichen planus and oral leukoplakia biopsies was performed using anticarbonic anhydrase IX antibody. Samples of normal mucosa served as controls. Statistical analysis was performed by Fischer's exact test. The enzyme was detected in the epithelium of both lesions. The staining was more intense in the basal layer and decreased towards the surface in oral lichen planus. Conversely, the most intense reaction was observed in the superficial layers in leukoplakia, and staining intensity decreased towards the basal membrane. No carbonic anhydrase IX expression was seen in normal mucosa samples. Carbon anhydrase IX expression in lichen and leukoplakia epithelia shows that hypoxia plays a role in the pathogenesis of both lesions. The different distribution patterns provides further evidence of the different biological behavior of these two entities, which under certain circumstances can have similar clinical and histological features (AU)

La hipoxia tumoral es un importante indicador de pronóstico en cáncer. Entre los distintos genes que son activados por hipoxia, uno de los principales es la anhidrasa carbónica IX (CAIX), que combina CO2 con H2O para sintetizar HCO3 y H+. Aunque la expresión de esta enzima es muy baja en tejidos normales, se sobreexpresa en varios tipos de cáncer. La finalidad del presente trabajo fue analizar la expresión de CAIX en las dos lesiones orales potencialmente malignas más frecuentes: el liquen plano y la leucoplasia. Se utilizó una técnica inmuno histoquímica con un anticuerpo específico contra CAIX, en biopsias de liquen plano oral y leucoplasia oral. Se utilizaron mucosas normales como controles. Se realizaron análisis estadísticos utilizando test exacto de Fischer. La identificación de la enzima fue positiva en el epitelio de ambas lesiones. En los líquenes la reacción es más intensa en los estratos basales, disminuyendo hacia la superficie. Inversamente, las leucoplasias mostraron marcación más intensa en estratos superficiales, con disminución hacia la membrana basal. Las mucosas normales resultaron negativas. La expresión de CAIX en el epitelio de líquenes y leucoplasias indica que la hipoxia juega algún papel en la patogenia de ambas lesiones. El diferente patrón de distribución es una evidencia más del diferente comportamiento biológico de dos entidades las cuales en ciertas circunstancias pueden manifestar cuadros clínicos e histológicos semejantes (AU)

Association of Carbonic Anhydrase IX Expression on the Prognosis and Therapeutic Response in Clear Cell Renal Cell Carcinoma / 계명의대학술지

Recent studies of Carbonic anhydrase IX (CAIX) expression and clinical significance in renal cell carcinoma (RCC) have given rise to disagreements in the usefulness of CAIX as a prognostic factor. The purpose of this study was to evaluate the association between CAIX expression and clinical factors in RCC. The medical record of 172 RCC patients in hospital (from January 1999 and December 2007) were reviewed retrospectively. Patients were divided into a high expression group (109 cases) and low expression group (63 cases) according to their degree of CAIX expression. We evaluated the association between CAIX expression and age, body mass index (BMI), type of renal neoplasm, tumor stage, nuclear grade, metastasis after surgery and tumor-specific survival rate. The mean age of the high expression group and the low expression group were 56 years and 54 years respectively. The mean BMI of the high expression group and the low expression group were 24.2 kg/m2 and 24.5 kg/m2 respectively. Comparing the difference between clear cell RCC and non clear cell RCC, CAIX was significantly more expressed in clear cell RCC. There was no significant differences between high expression clear cell RCC and low expression clear cell RCC according to age, BMI, nuclear grade, metastasis after surgery and tumor-specific survival rate (p=0.237, p=0.802, p=0.382, p=0.551). However, in clear cell RCC, CAIX expression was significantly more expressed in patients with higher T or N stages (p=0.015, p=0.033). CAIX was significantly higher expressed in clear cell RCC and was significantly lower expressed in patients with higher T stage or N stage.

Prognostic and predictive biomarkers for hypoxic regions on breast cancer: advances and challenges / Biomarcadores preditivos e prognósticos em regiões hipóxicas do câncer de mama: avanços e desafios

Hypoxia has been extensively studied in solid tumors mainly in breast cancers and it is commonly associated with chemotherapy and radiotherapy resistance. Hypoxia inducible factor (HIF)-1α is responsible for hypoxia in the tumor microenvironment and its molecular mechanisms as well as its therapeutic strategies have been described. However, a few investigations in the literature deal with its role in the hypoxic environment at diagnosis with the aim to guide therapeutic approaches. This study alerts researchers in pathology and oncology to the importance of assessing area extension as well as specific biomarkers, inasmuch as molecules reactive to hypoxia may indicate response to antiangiogenic therapy. The extension of hypoxic areas may alter the choice of therapeutic approach, insofar as some antiangiogenic treatments may considerably aggravate patient's clinical course since they create a hypoxic environment.

A hipóxia vem sendo bastante estudada nos tumores sólidos, principalmente nos de mama, os quais são frequentemente responsáveis pela resistência a quimioterapia e radioterapia. O hypoxia inducible factor (HIF)-1α é o principal responsável pela hipóxia no microambiente tumoral e seus mecanismos moleculares têm sido descritos, além de estratégias terapêuticas desenhadas para essa molécula. Porém, poucos estudos na literatura tratam do papel do microambiente hipóxico no momento do diagnóstico para colaborar com a conduta dos oncologistas. Este artigo alerta os pesquisadores em patologia e oncologia para que eles observem a importância da avaliação da extensão da área, bem como dos biomarcadores específicos para esse ambiente, já que moléculas responsivas à hipóxia podem ser indicativas de resposta à terapia antiangiogênica. A extensão das áreas hipóxicas pode mudar a decisão do oncologista na escolha da conduta terapêutica, visto que alguns tratamentos antiangiogênicos podem piorar consideravelmente a evolução clínica do paciente por criar um ambiente hipóxico.

Prognostic Relevance of the Expression of CA IX, GLUT-1, and VEGF in Ovarian Epithelial Cancers

BACKGROUND: Tumor hypoxia is associated with malignant progression and treatment resistance. Hypoxia-related factors, such as carbonic anhydrase IX (CA IX), glucose transporter-1 (GLUT-1), and vascular endothelial growth factor (VEGF) permit tumor cell adaptation to hypoxia. We attempted to elucidate the correlation of these markers with variable clinicopathological factors and overall prognosis. METHODS: Immunohistochemistry for CA IX, GLUT-1, and VEGF was performed on formalin-fixed, paraffin-embedded tissues from 125 cases of ovarian epithelial cancer (OEC). RESULTS: CA IX expression was significantly associated with an endometrioid and mucinous histology, nuclear grade, tumor necrosis, and mitosis. GLUT-1 expression was associated with tumor necrosis and mitosis. VEGF expression was correlated only with disease recurrence. Expression of each marker was not significant in terms of overall survival in OECs; however, there was a significant correlation between poor overall survival rate and high coexpression of these markers. CONCLUSIONS: The present study suggests that it is questionable whether CA IX, GLUT-1, or VEGF can be used alone as independent prognostic factors in OECs. Using at least two markers helps to predict patient outcomes in total OECs. Moreover, the inhibition of two target gene combinations might prove to be a novel anticancer therapy.

Prognostic significance of carbonic anhydrase IX expression in clear cell renal cell carcinoma / 中华泌尿外科杂志

Objective To evaluate the prognostic significance of carbonic anhydrase IX (CA IX) expression in patients with clear cell renal cell carcinoma (ccRCC). Methods CA IX expression in a cohort of 120 patients with ccRCC was evaluated by P-V immunohistochemistry with a rabbit CA IX polyclonal antibody. Twenty-five normal kidney tissues were used as a control. The relationship between CA IX expression and prognosis was analyzed by univariate and multiple-factor analysis (Cox regression model). The primary end point was cancer specific survival. Results One hundred and twelve (93.3%) patients were followed up with the median follow-up time of 45 months (range, 6 to 94 months). Seventy-five patients survived without evidence of tumor recurrence, 3 patients survived with tumor recurrence, and 34 patients died, 28 of the 34 died of cancer. CA IX expression was negative in all normal renal tissue. High CA IX expression was observed in 89 (74.2%) patients, among which 82 patients were followed up, and the disease free survival was 75.6% (62/82). Two (2.4%) patients survived with tumor recurrence, and 18 (22.0%) patients died, of which 13 (15.9%) died of cancer. Tumor recurrence and (or) metastasis occurred in 9 (11.0%) patients, with a median survival of 92 months in this high expression group. Low CA IX expression was observed in 31 (25.8%) patients, among which 30 patients were followed up, and the disease free survival was 43.3% (13/30). One (3.3%) patient survived with tumor recurrence, and 16 (53.3%) patients died, of which 15 (50.0%) died of cancer. Tumor recurrence and (or) metastasis occurred in 8 (26.7%) patients with a median survival of 53 months in this low expression group. Cancer specific survival between CA IX high expression group and low expression group was significantly different (P=0.000, χ2=15.950), and tumor relapse and (or) metastasis rates were significantly different (P=0.040, χ2=4.200). The 1, 3, 5 and 7 year cancer specific survival rates were 95.2%, 83.9%, 81.2% and 78.2% respectively in the high CA IX expression group, and 89.5%, 63.9%, 46.8% and 40.1% respectively in the low expression group. Multivariate analysis with Cox regression model showed that CA IX expression was a prognostic factor (RR=0.186). Conclusions High CA IX expression is negatively correlated with postoperative mortality, relapse and (or) metastasis in ccRCC. CA IX expression could be used as a prognostic biomarker in ccRCC.