Low HIF-1α and low EGFR mRNA Expression Significantly Associate with Poor Survival in Soft Tissue Sarcoma Patients; the Proteins React Differently

Abstract

In various tumors, the hypoxia inducible factor-1α (HIF-1α) and the epidermal growth factor-receptor (EGFR) have an impact on survival. Nevertheless, the prognostic impact of both markers for soft tissue sarcoma (STS) is not well studied. We examined 114 frozen tumor samples from adult soft tissue sarcoma patients and 19 frozen normal tissue samples. The mRNA levels of HIF-1α, EGFR, and the reference gene hypoxanthine phosphoribosyltransferase (HPRT) were quantified using a multiplex qPCR technique. In addition, levels of EGFR or HIF-1α protein were determined from 74 corresponding protein samples using ELISA techniques. Our analysis showed that a low level of HIF-1α or EGFR mRNA (respectively, relative risk (RR) = 2.8; p = 0.001 and RR = 1.9; p = 0.04; multivariate Cox´s regression analysis) is significantly associated with a poor prognosis in STS patients. The combination of both mRNAs in a multivariate Cox’s regression analysis resulted in an increased risk of early tumor-specific death of patients (RR = 3.1, p = 0.003) when both mRNA levels in the tumors were low. The EGFR protein level had no association with the survival of the patient’s cohort studied, and a higher level of HIF-1α protein associated only with a trend to significance (multivariate Cox’s regression analysis) to a poor prognosis in STS patients (RR = 1.9, p = 0.09). However, patients with low levels of HIF-1α protein and a high content of EGFR protein in the tumor had a three-fold better survival compared to patients without such constellation regarding the protein level of HIF-1α and EGFR. In a bivariate two-sided Spearman’s rank correlation, a significant correlation between the expression of HIF-1α mRNA and expression of EGFR mRNA (p < 0.001) or EGFR protein (p = 0.001) was found, additionally, EGFR mRNA correlated with EGFR protein level (p < 0.001). Our results show that low levels of HIF-1α mRNA or EGFR mRNA are negative independent prognostic markers for STS patients, especially after combination of both parameters. The protein levels showed a different effect on the prognosis. In addition, our analysis suggests a possible association between HIF-1α and EGFR expression in STS.

Prognostic impact of cytoplasmatic EGFR upregulation in patients with oral squamous cell carcinoma: A pilot study

“…Therefore it might be possible that the tumorous EGFR-protein level is very low, but the signaling pathway is highly activated. This is what we found in a cohort of STS patients, where EGFR levels were low but pAKT S473 protein levels were elevated (19,20). An explanation for such a situation could be that the interaction of high levels of EGFR ligands (e.g.…”

“…There is evidence that some cytoEGFR molecules can be translocated into the nucleus of tumor cells (9,29). In addition, different isoforms of EGFR could even have different targets/induce different pathways which could have different biological and therapeutic effects (13,19). Nuclear EGFR functioned as a transcription factor and induced proliferation-associated genes and increase the chemo-and radioresistance of tumor cells (3).…”

Investigation of the Prognostic Role of Carbonic Anhydrase 9 (CAIX) of the Cellular mRNA/Protein Level or Soluble CAIX Protein in Patients with Oral Squamous Cell Carcinoma

“…However, it can also be regulated by other factors such as EGFR [30,51]. In addition, even an association of EGFR and HIF-1α was postulated [52,53]. This means that a HIF1 activity is still affected by an EGFR-mediated activation of CAIX.…”

“…Six µg of total RNA was used for cDNA synthesis (tissue samples) according to standard protocols (Fermentas, St. Leon-Rot, Germany) with random hexamer primers in a Thermo-Trioblock TB1 (Biometra, Göttingen, Germany) for one hour at 42 °C as previously described [53,64]. The cDNA for the miRNA analysis was synthesized with the miRCURY LNA™ Universal RT microRNA PCR–Universal cDNA synthesis kit II Exiqon (Vedbæk; Denmark) according to the manufacturer’s protocol.…”

Prognostic Value of a Three-DNA Methylation Biomarker in Patients with Soft Tissue Sarcoma

“…PARP1 expression was considered as a prognostic factor in patients with STS [26]. Low expression of genes EGFR and HIF-1 in STS patients usually contributes to a poor prognosis [27]. e results of Pollino et al illustrated that increased gene expression of SDP35 promoted the progression of STS metastasis and could be used as an independent marker of poor prognosis in patients [28].…”