The effect of ephrin-A1 on resistance to Photofrin-mediated photodynamic therapy in esophageal squamous cell carcinoma cells.

Esophageal squamous cell carcinoma (ESCC), the most prevalent cell type of esophageal cancer, remains a dismal disease with poor prognosis. Photodynamic therapy (PDT) is a minimally invasive treatment option for early esophageal cancer. To explore possible factors involved in resistance to PDT in esophageal cancer cells, we selected PDT-resistant subcell lines by repeated treatment of CE48T/VGH (CE48T) ESCC cells with Photofrin-PDT and then analyzed the global gene modulations in the PDT-resistant cells by whole-genome microarray. More than 700 genes reached a fold change greater than 1.5 in each of the PDT-resistant cells compared to parental cells. Among these genes, both tumor necrosis factor (TNF) and EFNA1 genes were significantly upregulated in resistant cell lines. However, they were significantly downregulated in Photofrin-PDT-treated cells compared to untreated cells. The observations made in the microarray analysis were further confirmed by quantitative PCR. We observed that recombinant tumor necrosis factor alpha (TNF-α) activated the gene expression of EFNA1 at both the messenger RNA (mRNA) level and the protein level in CE48T cells. Functional analysis showed that when incubated with oligomeric and monomeric ephrin-A1 simultaneously, ESCC cells became significantly resistant to Photofrin-PDT. Functional analysis further suggested that transmembrane and soluble ephrin-A1 may cooperate to enhance resistance to Photofrin-PDT in ESCC cells.

The genetic effect and molecular function of the SOCS5 in the prognosis of esophageal squamous cell carcinoma.

Expression of cytokines and growth factors have been shown to be highly correlated with the prognosis of esophageal squamous cell carcinoma (ESCC), a deadly disease with poor prognosis. The suppressor of cytokine signaling (SOCS) family of proteins are key factors in regulating cytokines and growth factors. Yet the role of the SOCS proteins in ESCC is hardly investigated. We currently investigated the prognostic role of SOCS5 in ESCC. We analyzed the prognostic effects of 16 single nucleotide polymorphisms (SNPs) within the SOCS genes in 632 ESCC patients. We repeatedly observed that the 3 SNPs in SOCS5, SOCS5:rs3814039, SOCS5:rs3738890, and SOCS5: rs3768720, were significantly correlated with both overall (OS) and progression-free survival (PFS) of ESCC patients (rs3814039, p=0.032 for OS and p=0.009 for PFS; rs3738890, p=0.016 for OS, and p=0.008 for PFS; rs3768720, p=0.005 for OS and p=0.002 for PFS). SOCS5: rs3768720 was also significantly associated with distant metastasis (Ptrend=0.028). The luciferase assay revealed that SOCS5:rs3814039 and SOCS5: rs3768720 might influence the prognosis by regulating SOCS5 expression. Functional analysis demonstrated SOCS5 was able to regulate epidermal growth factor receptor (EGFR) expression and migration activity of ESCC cells. Furthermore, Patients with strong SOCS5 in normal tissues exhibited significantly better PFS (P=0.049) and reduced risk of distant metastasis (P=0.004) compared to those with weak SOCS5 expression. Overall, our study demonstrates the novel function of SOCS5 in ESCC prognosis. The genetic polymorphisms and expression of SOCS5 could serve as a novel therapeutic biomarker for improving the prognosis of ESCC.

Ascorbic acid-induced TET activation mitigates adverse hydroxymethylcytosine loss in renal cell carcinoma.

Although clear cell renal cell carcinoma (ccRCC) has been shown to result in widespread aberrant cytosine methylation and loss of 5-hydroxymethylcytosine (5hmC), the prognostic impact and therapeutic targeting of this epigenetic aberrancy has not been fully explored. Analysis of 576 primary ccRCC samples demonstrated that loss of 5hmC was strongly associated with aggressive clinicopathologic features and was an independent adverse prognostic factor. Loss of 5hmC also predicted reduced progression-free survival after resection of nonmetastatic disease. The loss of 5hmC in ccRCC was not due to mutational or transcriptional inactivation of ten eleven translocation (TET) enzymes, but to their functional inactivation by l-2-hydroxyglutarate (L2HG), which was overexpressed due to the deletion and underexpression of L2HG dehydrogenase (L2HGDH). Ascorbic acid (AA) reduced methylation and restored genome-wide 5hmC levels via TET activation. Fluorescence quenching of the recombinant TET-2 protein was unaffected by L2HG in the presence of AA. Pharmacologic AA treatment led to reduced growth of ccRCC in vitro and reduced tumor growth in vivo, with increased intratumoral 5hmC. These data demonstrate that reduced 5hmC is associated with reduced survival in ccRCC and provide a preclinical rationale for exploring the therapeutic potential of high-dose AA in ccRCC.

Antisense STAT3 inhibitor decreases viability of myelodysplastic and leukemic stem cells.

Acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) are associated with disease-initiating stem cells that are not eliminated by conventional therapies. Transcriptomic analysis of stem and progenitor populations in MDS and AML demonstrated overexpression of STAT3 that was validated in an independent cohort. STAT3 overexpression was predictive of a shorter survival and worse clinical features in a large MDS cohort. High STAT3 expression signature in MDS CD34+ cells was similar to known preleukemic gene signatures. Functionally, STAT3 inhibition by a clinical, antisense oligonucleotide, AZD9150, led to reduced viability and increased apoptosis in leukemic cell lines. AZD9150 was rapidly incorporated by primary MDS/AML stem and progenitor cells and led to increased hematopoietic differentiation. STAT3 knockdown also impaired leukemic growth in vivo and led to decreased expression of MCL1 and other oncogenic genes in malignant cells. These studies demonstrate that STAT3 is an adverse prognostic factor in MDS/AML and provide a preclinical rationale for studies using AZD9150 in these diseases.

The AXL receptor tyrosine kinase is associated with adverse prognosis and distant metastasis in esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is a frequently recurrent deadly cancer for which no efficient targeted drug exists. AXL is an adverse prognostic factor in some cancers. Strong clinical evidence to support the prognostic role of AXL in ESCC is lacking. A total of 116 patients diagnosed with operable primary ESCC were enrolled. Both AXL and HER2 expression were detected by immunohistochemistry (IHC) in esophageal tissue and were correlated with the clinical outcome of patients. The efficacy of the AXL targeted drug foretinib was also evaluated in ESCC cells. Expression of AXL was found in about 80 % of ESCC tissue, and was significantly correlated with progression of tumor (P<0.001), increased risk of death (Hazard ratio HR [95 % CI=2.09[1.09-4.04], P=0.028], and distant metastasis (odds ratio OR [95 %CI]=3.96 (1.16-13.60), P=0.029). The adverse clinical impact of AXL was more evident when cumulatively expressed with HER2. In cell model, ESCC cells were more sensitive to AXL inhibitor foretinib than to the HER2 inhibitor lapatinib. Meanwhile, the AXL inhibitor foretinib showed a synergistic effect with HER2 inhibitors and the potential to overcome drug resistance to lapatinib. We thus concluded that AXL is a strong adverse prognostic factor for ESCC. Therapeutic agents targeting AXL have great potential to improve prognosis of ESCC patients.

Visible-absorption spectroscopy as a biomarker to predict treatment response and prognosis of surgically resected esophageal cancer.

The application of optical absorption spectra in prognostic prediction has hardly been investigated. We developed and evaluated a novel two dimensional absorption spectrum measurement system (TDAS) for use in early diagnosis, evaluating response to chemoradiation, and making prognostic prediction. The absorption spectra of 120 sets of normal and tumor tissues from esophageal cancer patients were analyzed with TDAS ex-vivo. We demonstrated the cancerous tissue, the tissue from patients with a poor concurrent chemoradiotherapy (CCRT) response, and the tissue from patients with an early disease progression each had a readily identifiable common spectral signature. Principal component analysis (PCA) classified tissue spectra into distinct groups, demonstrating the feasibility of using absorption spectra in differentiating normal and tumor tissues, and in predicting CCRT response, poor survival and tumor recurrence (efficiencies of 75%, 100% and 85.7% respectively). Multivariate analysis revealed that patients identified as having poor-response, poor-survival and recurrence spectral signatures were correlated with increased risk of poor response to CCRT (P = 0.012), increased risk of death (P = 0.111) and increased risk of recurrence (P = 0.030) respectively. Our findings suggest that optical absorption microscopy has great potential to be a useful tool for pre-operative diagnosis and prognostic prediction of esophageal cancer.