High Id1 expression, a generally negative prognostic factor, paradoxically predicts a favorable prognosis for adjuvant paclitaxel plus cisplatin therapy in surgically treated lung cancer patients

The efficacy of sorafenib against hepatocellular carcinoma is enhanced by 5-aza-mediated inhibition of ID1 promoter methylation

Sorafenib resistance greatly restricts its clinical application in patients with hepatocellular carcinoma (HCC). Numerous studies have reported that ID1 exerts a crucial effect in cancer initiation and development. Our previous research revealed an inhibitory role of ID1 in sorafenib resistance. However, the upstream regulatory mechanism of ID1 expression is unclear. Here, we discovered that ID1 expression is negatively correlated with promoter methylation, which is regulated by DNMT3B. Knockdown of DNMT3B significantly inhibited ID1 methylation status and resulted in an increase of ID1 expression. The demethylating agent 5-aza-2'-deoxycytidine (5-aza) remarkably upregulated ID1 expression. The combination of 5-aza with sorafenib showed a synergistic effect on the inhibition of cell viability.

Methylation of CpG Sites as Biomarkers Predictive of Drug-Specific Patient Survival in Cancer

Background:

Though the development of targeted cancer drugs continues to accelerate, doctors still lack reliable methods for predicting patient response to standard-of-care therapies for most cancers. DNA methylation has been implicated in tumor drug response and is a promising source of predictive biomarkers of drug efficacy, yet the relationship between drug efficacy and DNA methylation remains largely unexplored.

Method:

In this analysis, we performed log-rank survival analyses on patients grouped by cancer and drug exposure to find CpG sites where binary methylation status is associated with differential survival in patients treated with a specific drug but not in patients with the same cancer who were not exposed to that drug. We also clustered these drug-specific CpG sites based on co-methylation among patients to identify broader methylation patterns that may be related to drug efficacy, which we investigated for transcription factor binding site enrichment using gene set enrichment analysis.

Results:

We identified CpG sites that were drug-specific predictors of survival in 38 cancer-drug patient groups across 15 cancers and 20 drugs. These included 11 CpG sites with similar drug-specific survival effects in multiple cancers. We also identified 76 clusters of CpG sites with stronger associations with patient drug response, many of which contained CpG sites in gene promoters containing transcription factor binding sites.

Conclusion:

These findings are promising biomarkers of drug response for a variety of drugs and contribute to our understanding of drug-methylation interactions in cancer. Investigation and validation of these results could lead to the development of targeted co-therapies aimed at manipulating methylation in order to improve efficacy of commonly used therapies and could improve patient survival and quality of life by furthering the effort toward drug response prediction.

Inhibitor of Differentiation 1 (ID1) Facilitates the Efficacy of Sorafenib in Non-Small Cell Lung Cancer Cells through Suppressing Epithelial to Mesenchymal Transition

BACKGROUND Sorafenib, which is a multitargeted kinase inhibitor, has shown some antitumor effects in patients with non-small cell lung cancer (NSCLC). However, the potential target of sorafenib's antitumor activity is largely unknown. Moreover, definitive predictive biomarkers of benefit have rarely been reported. MATERIAL AND METHODS The alteration in inhibitor of differentiation 1 (ID1) expression in NSCLC cells with sorafenib treatment was detected by western blotting. The sensitivity of NSCLC cells to sorafenib was observed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium) assay. Loss-of-function and gain-of-function experiments were performed to observe the role of ID1 expression in epithelial to mesenchymal transition (EMT) progression. RESULTS Initially, we observed that ID1 was downregulated in NSCLC cells treated with sorafenib. The response of NSCLC cells to sorafenib was inhibited by the transfection of small interfering RNAs (siRNAs) targeting ID1. In contrast, the transfection of ID1-overexpressing plasmids improved the response of NSCLC cells to sorafenib. Further experiments indicated that ID1 is expressed at high levels in epithelial H460 cells and expressed at low levels in mesenchymal H358 cells. Loss-of-function and gain-of-function experiments suggested that ID1 negatively regulates EMT in NSCLC. CONCLUSIONS The expression of ID1 is dose-dependently inhibited by sorafenib, and the overexpression of ID1 contributes to the antitumor activity of sorafenib by suppressing EMT development. Our results indicate that ID1 might be a potential target for the antitumor activity of sorafenib in NSCLC and that targeting ID1 is a feasible strategy to improve the sensitivity of NSCLC cells to sorafenib.

ID1 overexpression increases gefitinib sensitivity in non-small cell lung cancer by activating RIP3/MLKL-dependent necroptosis

ID1 is an oncogenic factor in cancer, but its role in relation to drug sensitivity is unclear. This study aimed to investigate the role of ID1 in drug sensitivity in non-small cell lung cancer (NSCLC). ID1 overexpression in NSCLC cells harboring either EGFR or KRAS mutation was performed and the sensitivity of NSCLC to gefitinib (ZD1839) was measured. A murine orthotopic lung carcinoma model with or without stable ID1 overexpression was developed and treated with gefitinib. Transcriptomic and bioinformatics analyses showed that ID1 overexpression promoted inflammation-related cell death but not apoptosis in gefitinib-treated NSCLC cells. ID1 induced necroptosis by triggering activation of RIP1/RIP3/MLKL pathways. Protein kinase array further suggested that ID1 overexpression maintains Akt activity in gefitinib-treated NSCLC cells, which in turn upregulated FLICE-like inhibitory protein to dissociate the caspase-8-RIP1 complex. The association of RIP1 and RIP3 further activated necroptotic cell death in gefitinib-treated NSCLC. In conclusion, ID1 overexpression in NSCLC induced cellular sensitivity to epidermal growth factor receptor tyrosine kinase inhibitors, regardless of the mutational status of NSCLC. The results may provide scientific evidence for optimizing the treatment outcomes of gefitinib for NSCLC patients.

Inhibitor of Differentiation 1 (Id1) in Cancer and Cancer Therapy

The inhibitor of DNA binding (Id) proteins are regulators of cell cycle and cell differentiation. Of all Id family proteins, Id1 is mostly linked to tumorigenesis, cellular senescence as well as cell proliferation and survival. Id1 is a stem cell-like gene more than a classical oncogene. Id1 is overexpressed in numerous types of cancers and exerts its promotion effect to these tumors through different pathways. Briefly, Id1 was found significantly correlated with EMT-related proteins, K-Ras signaling, EGFR signaling, BMP signaling, PI3K/Akt signaling, WNT and SHH signaling, c-Myc signaling, STAT3 signaling, RK1/2 MAPK/Egr1 pathway and TGF-β pathway, etc. Id1 has potent effect on facilitating tumorous angiogenesis and metastasis. Moreover, high expression of Id1 plays a facilitating role in the development of drug resistance, including chemoresistance, radiation resistance and resistance to drugs targeting angiogenesis. However, controversial results were also obtained. Overall, Id1 represent a promising target of anti-tumor therapeutics based on its potent promotion effect to cancer. Numerous drugs were found exerting their anti-tumor function through Id1-related signaling pathways, such as fucoidan, berberine, tetramethylpyrazine, crizotinib, cannabidiol and vinblastine.

Prognostic values of the inhibitor of DNA‑binding family members in breast cancer

The inhibitor of DNA‑binding (ID) proteins are dominant‑negative modulators of transcription factors with basic helix‑loop‑helix (bHLH) structures, which control a variety of genes in cell cycle regulation. An increasing volume of evidence has demonstrated that the deregulated expression of IDs in several types of malignancy, including breast carcinoma, has been proven to serve crucial regulatory functions in tumorigenesis and the development of breast cancer (BC). The present study evaluated the prognostic values of the ID family members by investigating a set of publicly accessible databases, including Oncomine, bc‑GenExMiner, Kaplan‑Meier plotter and the Human Protein Atlas. The results demonstrated that mRNA levels of distinct IDs exhibited diverse profiles between BC and normal counterparts. The mRNA expression level of ID2 was significantly higher in breast cancer than normal tissues, while the mRNA expression levels of ID1, ID3 and ID4 were significantly lower in breast cancer tissues than in normal tissues. Furthermore, higher mRNA expression levels of ID1 and ID4 were associated with subgroups with lower pathological grades and fewer lymph node metastases. Survival analysis revealed that elevated mRNA levels of ID1 and ID4 predicted an improved survival in all patients with BC. Increased ID1 mRNA levels were associated with higher relapse‑free survival rates in all patients with BC, particularly in those with ER positive and Luminal A subtype tumors. Increased ID4 mRNA expression predicted longer survival times in all patients with BC, particularly in those with hormone receptor‑positive tumors or those treated with endocrine therapy. These results indicated that IDs are essential prognostic indicators in BC. Future studies on the effect of IDs on the pathogenesis and development of BC are warranted.

ID1-induced p16/IL6 axis activation contributes to the resistant of hepatocellular carcinoma cells to sorafenib

Sorafenib is the only approved drug for the treatment of advanced hepatocellular carcinoma (HCC). However, its efficacy is limited by the emergence of primary and/or acquired resistance. Senescence-associated secretory phenotype (SASP)-mediated chemo-resistance, which depends on the secreted bioactive molecules, has attracted increasing attention but never revealed in HCC. In this study, we investigated the effect of SASP-related p16/IL6 axis on sorafenib resistance in HCC. Initially, we noticed that HCC cells with a high level of p16/IL6 axis exhibited a low sensitivity to sorafenib. Further in vivo and in vitro studies demonstrated that such a primary resistance resulted from ID1-mediated activation of p16/IL6 axis. Overexpression of ID1 or IL6 blocking in sorafenib-resistant HCC cells could increase the cytotoxicity of sorafenib. Moreover, SASP-related p16/IL6 axis contributed to the formation of acquired resistance in cells received long-term exposure to sorafenib. In acquired sorafenib-resistant cells, ID1 low expression, p16/IL6 axis up-regulation, and AKT phosphorylation activation were observed. A reduced cytotoxicity of sorafenib was detected when sorafenib-sensitive cells incubated with conditioned media from the resistant cells, accompanied by the stimulation of AKT phosphorylation. The reversal of sorafenib resistance could be achieved through ID1 overexpression, IL6 blocking, and AKT pathway inhibition. Our study reveals that SASP-related p16/IL6 axis activation is responsible for sorafenib resistance, which will be a novel strategy to prevent the drug resistance.

RNA-sequencing dissects the transcriptome of polyploid cancer cells that are resistant to combined treatments of cisplatin with paclitaxel and docetaxel

Overcoming chemoresistance will prevent cancer relapse and contribute to clinical chemotherapy. In order to explore the underlying mechanism of chemoresistance, we firstly incubated cancer cells with a combination of cisplatin + paclitaxel (C + P) or cisplatin + paclitaxel + docetaxel (C + P + D) to mimic the treatment of cancer therapy in the laboratory. We found that polyploidy is a recurring strategy that cells adopt in response to cisplatin-based treatments. RNA-sequencing was performed to identify differentially expressed genes (DEGs) that may contribute to drug resistance. 4830 and 5518 DEGs were discovered in C + P and C + P + D resistant cells, respectively, and 4384 (73.40%) genes were shared. Possible drug resistance genes like Atg14, Abcb1b, Tbx2, Slc2a9, Slc10a3 and Slc22a18 were up-regulated while Foxm1, Bcl2, Brca1, Chek1, Hiatl1 and Abcb9 were down regulated. Genes involved in the pathways of p53 signaling, lysosomes and apoptosis were up-regulated, and in contrast, genes in the cell cycle, DNA replication, and mismatch repair pathways were down-regulated. Moreover, representative proteins relative to DEGs were examined to validate the results of RNA-seq and RT-PCR. Taken together, these results will contribute to revealing the mechanism of chemoresistance and discovering potential prognostic factors for cancer medication.

Expression of redox sensing factor Nrf2 in lung macrophages and type II pneumocytes as a prognostic factor in pneumothorax recurrence

BACKGROUND

Primary spontaneous pneumothorax (PSP) is a common clinical problem. However, PSP recurrence is still a major concern. Nuclear factor erythroid 2-related factor 2 (Nrf2) plays a protective role against oxidative airway diseases. The aim was to investigate the role of Nrf2 in PSP patients and its correlation with recurrence.

METHODS

Eighty-nine patients were enrolled and received wedge resection of lung with identifiable blebs. Nrf2 expression in resected lung tissues was determined by immunohistochemistry (IHC) and correlated with clinicopathological variables. The prognostic value of Nrf2 for incidence-of-recurrence was determined by Kaplan-Meier estimates and the significance of differences was evaluated by the log-rank test.

RESULTS

Nrf2 staining was predominantly observed in alveolar macrophages and type II pneumocytes of PSP patients and correlated with recurrence (P<0.001 and P=0.001, respectively) and PSP location (macrophages, P=0.013). High Nrf2 expression was correlated with better incidence-of-recurrence (macrophages, P=0.003; type II pneumocytes, P=0.003). Moreover, incidence-of-recurrence was better in patients with higher Nrf2 expression, especially those in the age ≤20, male, and non-smoking groups (macrophages, P=0.009, 0.006, and 0.012; type II pneumocytes, P=0.003, 0.011, and 0.010, respectively).

CONCLUSIONS

High Nrf2 expression in alveolar macrophages and type II pneumocytes was significantly associated with the decreased recurrence risk and was the independent factor predicting a better incidence-of-recurrence in PSP. Our results suggest that Nrf2 activation in high risk patients may be a potential target for reducing PSP recurrence.

[Relationship between ID1 and EGFR-TKI Resistance in Non-small Cell Lung Cancer]

背景与目的

非小细胞肺癌(non-small cell lung cancer, NSCLC)是当今世界上发病率和死亡率最高的恶性肿瘤之一，而表皮生长因子受体-酪氨酸激酶抑制剂(epidermal growth factor receptor-tyrosine kinase inhibitors, EGFR-TKI)整体有效率为30%-40%，无进展生存期(progression-free survival, PFS)为12个月。但EGFR-TKI在临床中的耐药现象也很普遍，严重影响了其抑瘤作用。因此，克服耐药、寻找一种新的与肺癌耐药相关的预后因子势在必行。本研究旨在通过体内外实验探讨DNA结合抑制因子1(differentiation inhibitory factor 1, ID1)与NSCLCEGFR-TKI耐药之间的关系，看其是否有统计学意义，并初步探讨其机制。

方法

免疫组化(immunohistochemistry, IHC)检测手术标本(肺癌组织和癌旁组织)1D1的表达；qRT-PCR、Western-blot检测并比较肺癌细胞敏感株与耐药株中ID1的表达变化；MTT检测吉非替尼对ID1慢病毒载体处理肺癌细胞的细胞增殖情况，将肺癌细胞接种至裸鼠腋下，待肿瘤生长至一定体积使用吉非替尼治疗，估算肿瘤体积。

结果

ID1在肺癌组织中的表达明显高于正常组织(P < 0.05)；ID1的表达与NSCLC EGFR-TKI耐药呈正相关(P < 0.05)。

结论

ID1在NSCLC中高表达，并且参与了NSCLC EGFR-TKI的耐药，其机制可能与STAT3磷酸化程度增加有关。

The Synthetic β-Nitrostyrene Derivative CYT-Rx20 Inhibits Esophageal Tumor Growth and Metastasis via PI3K/AKT and STAT3 Pathways

The β-nitrostyrene family have been implicated for anti-cancer property. However, the pharmacological role of β-nitrostyrene in esophageal cancer remain unclear. Here, a β-nitrostyrene derivative, CYT-Rx20, was synthesized and assessed for its anti-cancer activities and underlying mechanism in esophageal cancer. CYT-Rx20 induced cytotoxicity in esophageal cancer cells by promoting apoptosis through activation of caspase cascade and poly(ADP-ribose) polymerase (PARP) cleavage. Besides, CYT-Rx20 inhibited esophageal cancer cell migration and invasion by regulating the expression of epithelial to mesenchymal transition (EMT) markers. CYT-Rx20 decreased cell viability and migration through suppression of the PI3K/AKT and STAT3 pathways. Of note, the cytotoxicity and anti-migratory effect of CYT-Rx20 were enhanced by co-treatment with SC79 (AKT activator) or colivelin (STAT3 activator), suggesting the dependency of esophageal cancer cells on AKT and STAT3 for survival and migration, an oncogene addiction phenomenon. In xenograft tumor-bearing mice, CYT-Rx20 significantly reduced tumor growth of the implanted esophageal cancer cells accompanied by decreased Ki-67, phospho-AKT, and phospho-STAT3 expression. In orthotopic esophageal cancer mouse model, decreased tumor growth and lung metastasis with reduced Ki-67 and phospho-STAT3 expression were observed in mice treated with CYT-Rx20. Together, our results suggest that CYT-Rx20 is a potential β-nitrostyrene-based anticancer compound against the tumor growth and metastasis of esophageal cancer.

Tyrosine-protein phosphatase non-receptor type 12 expression is a good prognostic factor in resectable non-small cell lung cancer

Tyrosine-protein phosphatase non-receptor type 12 (PTPN12) has been considered to be a tumor suppressor in human cancer, but its clinical and prognostic significance in non-small cell lung cancer (NSCLC) has not been well elucidated.

A retrospective analysis of 215 patients with surgically resected NSCLCs from Sun Yat-Sen University Cancer Center between April 2002 and March 2005 was performed using immunohistochemistry and Western Blot to analyze PTPN12 expression. The association between PTPN12 expression and patient survival was investigated.

Western Blots showed that the expression level of PTPN12 were higher in normal paracancerous lung tissues than in NSCLC tissues. High PTPN12 expression was less common in the presence than in the absence of visceral pleural invasion (p=0.038). Patients with PTPN12-high tumors had a longer disease-free survival (DFS) (P<0.001) and overall survival (OS) (p<0.001), especially for those with non-squamous cell carcinoma (non-SCC) (DFS, p<0.001; OS, p<0.001). Multivariate analysis confirmed that PTPN12 positivity was associated with increased survival duration (DFS, p<0.001; OS, p<0.001), independent of prognostic indicator.

High PTPN12 expressive levels are associated with favorable survival duration in patients with NSCLC, especially those with non-SCC. Our study suggests that PTPN12 expression is a valuable prognostic biomarker for NSCLC patients.