Differential expression of hypoxia-inducible factor 1α in non-small cell lung cancer and small cell lung cancer

OBJECTIVES:

The aim of this study was to compare the expression of hypoxia-inducible factor 1α and vascular endothelial growth factor in small cell lung cancer and subtypes of non-small cell lung cancer and examine their relationships with clinicopathologic factors, response to treatment and survival.

METHODS:

We examined samples obtained by bronchial endoscopic biopsy from 55 patients with inoperable lung cancer (16 with adenocarcinoma, 17 with squamous cell carcinoma, and 22 with small cell lung cancer). Hypoxia-inducible factor 1α and vascular endothelial growth factor were detected using immunohistochemistry. The diagnosis, treatment, and follow-up of patients were conducted according to the standard practice.

RESULTS:

A significant difference (p = 0.022) in hypoxia-inducible factor 1α expression was observed between non-small cell lung cancer (75.8% positive) and small cell lung cancer (45.5% positive). The frequency of hypoxia-inducible factor 1α nuclear expression was 88.2% in squamous cell carcinoma, 62.5% in adenocarcinoma, and 45.5% in small cell lung cancer. A significant correlation was observed between hypoxia-inducible factor 1α and vascular endothelial growth factor expression (Fisher''s exact test, p = 0.001) when all types of lung cancer were examined, either collectively or separately.

CONCLUSIONS:

The expression of hypoxia-inducible factor-1α differs significantly between subtypes of lung cancer. These findings could help elucidate the biology of the different types of non-operable lung carcinomas and have implications for the design of new therapeutic approaches for lung cancer.     

Prognostic role of integrin β1, E-cadherin, and rac1 expression in small cell lung cancer

Integrin β(1) mediates cellular adhesion to the extracellular matrix (ECM) and is correlated with highly invasive and metastatic behavior in small cell lung cancer (SCLC). E-cadherin (ECAD) is a calcium-dependent cell-cell adhesion receptor that restricts invasion of cells and reduces metastasis. Rac1 is involved in the regulation of the actin cytoskeleton, adhesion, migration, invasion, and tumor metastasis. The aim of this study was to examine integrin β(1) , ECAD and rac1 expression in SCLC and to analyze the prognostic value of these markers in patients with SCLC. We analyzed integrin β(1) , ECAD, and rac1 expression in 112 SCLC tissues by immunohistochemical staining. Correlative analyses between integrin β(1) , ECAD, and rac1 expression and cliniopathological factors were performed. A total of 65 patients had extensive disease (ED) (58%), and 47 had limited disease (LD) (42%). The median follow-up duration was 61 months (range: 14-117 months), and the median progression free survival (PFS) and overall survival (OS) were 6.1 months (range: 4.8-7.4 months) and 9.7 months (range: 8.1-11.3 months), respectively. The expression of integrin β(1) , ECAD, and rac1 protein was observed in 64, 73, and 99 of SCLC tissues, respectively. The correlative analyses between integrin β(1) , ECAD, or rac1 expression and various clinical parameters did not show any statistical significance. However, the ECAD expression was associated with OS in the entire cohort. In contrast, the expression of integrin β(1) and rac1 was not associated with PFS or OS. In a subgroup analysis, patients with less than two metastasis had significantly longer OS (p = 0.047) if their tumors expressed integrin β(1) compared to those without integrin β(1) expression. In addition, OS was longer for patients with ECAD positive tumors compared to those whose tumors did not express ECAD in males (p = 0.032) and patients who never smoked (p < 0.001). Multivariate analysis showed that LD (p = 0.004), overall response rate (p = 0.003), and expression of ECAD (p = 0.015) were the independent good prognostic factors for OS. LD (p = 0.024), overall response rate (p < 0.001), and less than two metastasis (p = 0.003) were prognostic factors for longer PFS. These results suggest that ECAD expression may be useful as a prognostic indicator in patients with SCLC.     

Clinicopathological significance and prognostic implication of nuclear factor-κB activation in colorectal cancer

ObjectiveThe aim of the present study was to evaluate the clinicopathological significance of phosphorylated nuclear factor-κB (pNF-κB) expression, and its impact on epithelial–mesenchymal transition and angiogenesis in colorectal cancer (CRC).MethodsWe carried out immunohistochemistry of pNF-κB on 261 human CRC tissues, and evaluated nuclear expression, regardless of cytoplasmic expression. We also investigated the correlation between pNF-κB expression and clinicopathological characteristics, survival, and epithelial–mesenchymal transition and angiogenesis-related markers in CRC.ResultspNF-κB was expressed in the nuclei of 164 of the 261 CRC tissues (62.8%). Furthermore, pNF-κB was significantly correlated with frequent perineural invasion, lymph node metastasis, and higher pTNM stage. However, there was no significant correlation between pNF-κB expression and other clinicopathological parameters. Among the epithelial–mesenchymal transition markers examined, SNAIL expression was significantly correlated with pNF-κB expression (P = 0.001) but E-cadherin expression was not. CRC with pNF-κB expression had significantly higher SIRT1 expression levels and hypoxia-inducible factor-1α expression levels than CRC without pNF-κB expression (P < 0.001 and P < 0.001, respectively). However, there was no correlation between the expression levels of pNF-κB and VEGF. pNF-κB expression was significantly correlated with worse overall and recurrence-free survival rates (P < 0.001 and P < 0.001, respectively).ConclusionpNF-κB expression was significantly correlated with aggressive tumor behaviors and worse survival rates. Furthermore, pNF-κB expression may affect tumor invasion and progression through SNAIL-related epithelial–mesenchymal transition and SIRT1- and hypoxia-inducible factor-1α-induced angiogenesis.     

Expression and significance of HIF-1α and VEGF-C in gastric carcinoma

Objective The present studies aimed at studying the expression and significance of HIF-1α and VEGF-C in gastric carcinoma. Methods SP method was used for the immunohistochemical detection of HIF-1α and VEGF-C proteins in paraffin embedded archival samples from 44 patients with gastric carcinoma and 20 normal gastric tissues. Results In 44 cases, the positive rate of HIF-1αwas 59.09%(26/44)and 23 cases 52. 27%(23/44)showed VEGF-C positive in cytoplasm and they were significantly higher than those in gastric normal tissue. The positive rate of HIF-1α in gastric cancer tissue expression with lymph node metastasis was higher than that without lymph node metastasis(72. 41% 21/29 vs 33.33 % 5/15;x2 = 6.25, P ＜ 0. 05).The positive rate of VEGF-C expression with lymph node metastasis and that without lymph node metastasis was 65. 52%(19/29)and 26. 67%(4/15)respectively(x2 = 4. 53, P ＜ 0. 05). The expression of HIF-1α and VEGF-C was closely correlated with lymph node metastasis and the depth of tumor invasion(x2 = 5. 14,P ＜ 0. 05, and x2 = 4. 38, P ＜ 0. 05), but no relationship with tumor position, sex and age. The positive expression of HIF-1α was consistent with the positive expression of VEGF-C. Conclusion The up regulated expression of HIF-1α and VEGF-C were observed in gastric cancer. The expression of HIF-1α and VEGF-C were correlated with lymph node metastasis and they were of some value for predicting prognosis of gastric carcinoma.     

Downregulation of ALDH1A1 expression in non-small cell lung carcinomas – its clinicopathologic and biological significance

ALDH1A1 metabolizes a variety of endogenous and exogenous aldehyde, and also oxidizes retinol to synthesize retinoic acid and modulate cell differentiation. Moreover, ALDH1A1 is also suggested to participate in the maintenance of cancer stem cells. To investigate the potential role of ALDH1A1 in carcinogenesis of the lung, the present study examined two hundred and sixty eight cases of non-small cell lung carcinoma (NSCLC) for its immunohistochemical expression and analyzed associations between ALDH1A1 levels and a series of clinicopathologic parameters. Also, the biological significance of the aberrant expression of ALDH1A1 was investigated in vitro. ALDH1A1 expression was markedly reduced in 39.9% (107/268) of NSCLCs. The incidence of this reduction was significantly higher in adenocarcinomas (ADC: 41.6%, 85/207) and large cell carcinomas (61.1%, 11/18) than squamous cell carcinomas (25.5%, 11/43). Among ADCs, the downregulation tended to be more remarkable in high grade, poorly differentiated tumors, and tumors with stronger proliferating activity. It also occurred with a significantly higher incidence in smokers than non-smokers. Forced expression of ALDH1A1 in NSCLC cell lines, which had lost ALDH1A1 expression, markedly attenuated their growth. Taken together, loss of ALDH1A1 expression is suggested to promote carcinogenesis especially in the smoking-related ADCs.     

Immune checkpoint blockade and biomarkers of clinical response in non–small cell lung cancer

Immunotherapy with PD-1 and PD-L1 inhibitors has revolutionized the treatment for patients with NSCLC the last years with increased overall survival and in particular increased number of long-time survivors in patients with metastatic disease. It is now a treatment of choice for patients with distant metastases (stage IV) and in conjunction with chemoradiotherapy for patients with limited spread confined to the chest (stage III). PD-1 inhibition has been proven to be superior to standard chemotherapy, both as a single treatment and when combined with either chemotherapy or CTLA-4 inhibition. Despite the success of immunotherapy, the majority of patients do not respond or relapse within a short time frame. Biomarkers that would help to properly select patients with a high likelihood of clinical response to PD-1 and PD-L1 inhibitors are scarce and far from optimal, and only one (PD-L1 expression) has reached clinical practice. Thus for immunotherapy to be effective, the discovery and validation of additional biomarkers is critical for patient selection and prediction of clinical response. In this mini-review, we give an overview of current clinical management of NSCLC including treatment landscape with regard to immunotherapy, as well as discuss the current genetic and immune cell biomarker studies and their potential for introduction into clinical practice.     

Inhibin-α subunit expression in uterine endometrioid adenocarcinomas and endometrial cancer cell lines: a potential prognostic factor

Inhibins/activins are secreted polypeptides of the transforming growth factor-β superfamily, forming a family of dimeric, disulphide-linked proteins. Inhibins are composed of an α-subunit and one of two possible β-subunits. Both inhibins and activins have substantial roles in human reproduction and in endocrine-responsive tumors. However, the prognostic significance and clinical implications of the inhibin-α subunits in uterine endometrioid adenocarcinomas is still not clearly defined. A series of 231 uterine endometrioid adenocarcinomas of a previous well-characterized cohort were re-evaluated for the expression of the inhibin-α subunit and correlated with several clinicopathological characteristics and clinical outcome. Additionally, several endometrial epithelial cell lines (Ishikawa plus and minus, HEC-1A, HEC-1B and RL95-2) were analyzed for the expression of this subunit using immunohistochemical and molecular biological techniques. A significant association between the inhibin-α subunit and histological grade, surgical staging and myometrial invasion was demonstrated. Survival analysis demonstrated that inhibin-α immunoreactivity significantly affected progression-free, cause-specific and overall survival of patients with endometrioid adenocarcinomas. The analyzed endometrial cancer cell lines can also synthesize this subunit. Inhibin-α seems to have a substantial role in the carcinogenesis and pathology of uterine endometrioid carcinomas, and might be used as a marker to identify high-risk patients and may aid in the selection of patients for a more aggressive adjuvant therapy. Since uterine cancer cell lines express the inhibin-α subunit, they constitute adequate in vitro models for assessing its function in endometrial carcinogenesis. However, further research is warranted to elucidate the possible implications of inhibin-α in endometrial carcinogenesis.     

Expression of RORα in gastric cancer and clinical pathological significance

目的 观察维甲酸相关孤核受体α(Retinoid acid receptor related Orphan Receptor α,RORα)蛋白在胃癌中的表达,探讨其与胃癌发生、发展的关系,为寻找胃癌肿瘤标记物提供一定的实验依据.方法 应用组织芯片技术及免疫组化SP法检测90例胃癌组织、48例癌旁胃黏膜组织与22例正常胃黏膜组织中RORα的表达,研究RORα与胃癌发生、发展的关系.结果 RORα蛋白在胃癌组织中表达下调,正常胃黏膜、癌旁胃黏膜和胃癌组织中RORα蛋白阳性率分别为83.36%(19/22),56.25%(27/48)和24.44%(22/90),3者相比差异有显著性(P＜0.05).高分化腺癌、中分化腺癌、低分化腺癌、黏液腺癌和印戒细胞癌中,RORα阳性率分别为45.00%(9/20)、27.59%(8/29)、14.29%(3/21)、11.11%(1/9)和9.05%(1/11).高分化腺癌RORα阳性率高于低分化腺癌(P＜0.05).结论 RORα蛋白下调与胃癌的发生、发展相关,且可能与胃癌的分化程度有关.     

Increased size of solid organs in patients with Chuvash polycythemia and in mice with altered expression of HIF-1α and HIF-2α

Chuvash polycythemia, the first hereditary disease associated with dysregulated oxygen-sensing to be recognized, is characterized by a homozygous germ-line loss-of-function mutation of the VHL gene (VHL ^R200W ) resulting in elevated hypoxia inducible factor (HIF)-1α and HIF-2α levels, increased red cell mass and propensity to thrombosis. Organ volume is determined by the size and number of cells, and the underlying molecular control mechanisms are not fully elucidated. Work from several groups has demonstrated that the proliferation of cells is regulated in opposite directions by HIF-1α and HIF-2α. HIF-1α inhibits cell proliferation by displacing MYC from the promoter of the gene encoding the cyclin-dependent kinase inhibitor, p21^Cip1, thereby inducing its expression. In contrast, HIF-2α promotes MYC activity and cell proliferation. Here we report that the volumes of liver, spleen, and kidneys relative to body mass were larger in 30 individuals with Chuvash polycythemia than in 30 matched Chuvash controls. In Hif1a ^+/? mice, which are heterozygous for a null (knockout) allele at the locus encoding HIF-1α, hepatic HIF-2α mRNA was increased (2-fold) and the mass of the liver was increased, compared with wild-type littermates, without significant difference in cell volume. Hepatic p21 ^Cip1 mRNA levels were 9.5-fold lower in Hif1a ^+/? mice compared with wild-type littermates. These data suggest that, in addition to increased red cell mass, the sizes of liver, spleen, and kidneys are increased in Chuvash polycythemia. At least in the liver, this phenotype may result from increased HIF-2α and decreased p21^Cip1 levels leading to increased hepatocyte proliferation.     

Study of hypoxia-induced expression of HIF-1α in retina pigment epithelium

It was shown that the expression of HIF-1α in retinal pigment epithelium increased under hypoxic conditions. Eight hours after the start of hypoxic exposure, the expression of HIF-1α reached the peak and sustained after 24-hour hypoxia. However, the morphology of PRE cells began to change and the expression of HIF-1α decreased after long-term (48-hour) hypoxia. Hypoxia-induced increase in the level of HIF-1α in RPE. It can be an important step in choriodal neovascularization. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 143, No. 3, pp. 293–297, March, 2007     

SMARCA4 and SMARCA2 deficiency in non–small cell lung cancer: immunohistochemical survey of 316 consecutive specimens

The chromatin remodeling switch sucrose nonfermentable (SWI/SNF) complex has been increasingly implicated in the pathogenesis and dedifferentiation of neoplasms from several organs with prognostic and potential therapeutic implications. We herein investigated the expression of the SWI/SNF complex catalytic subunits SMARCA4 (BRG1) and SMARCA2 (BRM) in 316 consecutive non-small cell lung cancer (NSCLC) specimens on tissue microarrays (171 adenocarcinomas [ADCAs], 130 squamous cell carcinomas [SCCs], 9 adenosquamous carcinomas, and 6 large cell carcinomas) excluding undifferentiated/giant cell or rhabdoid carcinomas. Complete loss of SMARCA4 was observed in 8 (5.5%) of 146 evaluable pulmonary ADCAs and 6 (5.2%) of 115 evaluable pulmonary SCCs, whereas 9 (6.4%) of 140 ADCAs and 2 (1.7%) of 117 SCCs showed SMARCA2 loss. Two of 6 large cell carcinomas were SMARCA2 deficient. Concurrent loss of both markers was observed in 4 cases (2 ADCAs and 2 SCCs). Of 15 ADCAs with loss of either or both markers, 12 (80%) were TTF1 negative. In conclusion, SMARCA4 and SMARCA2 deficiency is observed in 5.1% and 4.8% of NSCLC, respectively. SMARCB1 expression was intact in all cases. The presence of differentiated histology (glandular or squamous) is a novel aspect among SWI/SNF-deficient carcinomas which in other organs generally are associated with undifferentiated/rhabdoid morphology. The predominance of TTF1 negativity among SWI/SNF-deficient pulmonary ADCA (80%) underlines the need to include these 2 markers in the evaluation of TTF1-negative ADCA of putative pulmonary origin. Given the recently documented potential of SMARCA4 loss as a predictor of chemosensitivity to platinum-based chemotherapy in NSCLC, recognition of the clinicopathological features of SMARCA4-deficient NSCLC in routine surgical pathology practice is recommended.     

Effects of HIF-1α on human gastric cancer cell apoptosis at different CO2 pressures

The effects and potential molecular mechanisms underlying carbon dioxide (CO₂) pneumoperitoneum on gastric cancer cell apoptosis are not fully understood. In this study, we assessed the effects of CO₂ pneumoperitoneum on the apoptosis of MKN-45 gastric cancer cells. Additionally, we investigated the role of HIF-1α in CO₂ pneumoperitoneum-induced apoptosis of gastric cancer cells. MKN-45 cells were cultured in CO₂ or air pneumoperitoneum at 0, 12 and 15 mmHg pressures for 4 h. We observed a change in cells morphology and increasing apoptotic ratios in MKN-45 cells when they were put into a 15 mmHg CO₂ pneumoperitoneum environment. However, there was no significant difference between the 0, 12 mmHg CO₂ pneumoperitoneum and the control groups. Exposure to 15 mmHg CO₂ pneumoperitoneum significantly enhanced the expression levels of HIF-1α and Bax, while it attenuated Bcl-2 expression levels. When we inhibited HIF-1α by small interfering RNA (siRNA), we found that the apoptotic ratio of MKN-45 cells decreased in 15 mmHg CO₂ pneumoperitoneum. This treatment markedly elevated Bcl-2 levels and decreased Bax expression. These data suggest that CO₂ pneumoperitoneum may accelerate the apoptosis of MKN-45 cells at higher pressures. HIF-1α is a crucial factor that affects gastric cancer cell apoptosis by downregulating the Bcl-2/Bax ratio.