Correlation between the expression of Id-1 and hyperthermia-associated molecules in oral squamous cell carcinoma

Gains of 20q11.21 in human pluripotent stem cells: Insights from cancer research

The genetic abnormalities observed in hPSC cultures worldwide have been suggested to pose an important hurdle in their safe use in regenerative medicine due to the possibility of oncogenic transformation by mutant cells in the patient posttransplantation. One of the best-characterized genetic lesions in hPSCs is the gain of 20q11.21, found in 20% of hPSC lines worldwide, and strikingly, also amplified in 20% of human cancers. In this review, we have curated the existing knowledge on the incidence of this mutation in hPSCs and cancer, explored the significance of chromosome 20q11.21 amplification in cancer progression, and reviewed the oncogenic role of the genes in the smallest common region of gain, to shed light on the significance of this mutation in hPSC-based cell therapy. Lastly, we discuss the state-of-the-art strategies devised to detect aneuploidies in hPSC cultures, avoid genetic changes in vitro cultures of hPSCs, and strategies to eliminate genetically abnormal cells from culture.

RING induces cell cycle arrest and apoptosis in human breast cancer cells by regulating the HSF1/MT2A axis

It was reported that lowly expressed RING1 indicates poor prognosis in breast cancer (BC) patients, while the mechanism by which RING1 is involved in BC progression is not fully understood. Here, we found that RING1 was lowly expressed in BC tissues and cells than in normal mammary tissues and epithelial cells. Overexpression of RING1 suppressed the cell proliferative and colony formation abilities, and facilitated cell cycle arrest and cell apoptosis in BC cells (T47D and MCF-7 cells). Mechanistically, as an ubiquitin ligase, RING1 bound to HSF1 and induced its proteasome-dependent degradation. HSF1 could bind to the promoter region of MT2A to promote the transcriptional level of MT2A. While RING1 overexpression hindered the transcriptional activation of MT2A induced by HSF1. Moreover, ectopic expression of MT2A reversed the inhibitory effect of RING1 on cell proliferation and clonogenesis, and antagonized the promotion effect of RING1 on cell cycle arrest and apoptosis in BC cells. Additionally, T47D cells infected with or without lentivirus-mediated RING1 overexpression vector (LV-RING1) were injected subcutaneously into the right back of nude mice to evaluate tumorigenicity. And overexpression of RING1 impeded the growth of BC xenografts in mice. In conclusion, RING1 suppressed the transcriptional activation of MT2A induced by HSF1 by facilitating the ubiquitination degradation of HSF1, resulting in cell cycle arrest and apoptosis in BC cells.

Prognostic ability of DNA-binding protein inhibitor ID-1 expression in patients with oral squamous cell carcinoma

DNA-binding protein inhibitor ID-1 (ID-1) plays a vital role in the development of cancer. In the present study, ID-1 expression in oral squamous cell carcinoma (OSCC), and its association with prognosis were investigated in 128 patients with OSCC, treated at the Qilu Hospital of Shandong University and followed up for an additional 10 years. Immunohistochemical analysis was performed to detect ID-1 expression, and the association between ID-1 expression and recurrence, and estimated disease-specific survival (DSS) time were subsequently analyzed using the Mann-Whitney U test and the Kaplan-Meier method, respectively. In addition, the log-rank test was implemented to compare the survival curves and multivariate Cox proportional hazards analysis was performed to assess the prognostic value of ID-1. The results demonstrated that ID-1 was highly expressed in the majority of OSCC tissues investigated, and ID-1 expression was significantly higher in cases with recurrence of local tumors and lymph node metastasis. Furthermore, higher ID-1 expression levels were associated with a shorter DSS time. Taken together, the results of the present study suggest that ID-1 may serve as an independent prognostic factor to predict DSS time in patients with OSCC.

A study of the impact of inhibitors of DNA binding-1 on proliferation and migration in human colon carcinoma cells

This study aims to explore the effect of an inhibitor of DNA binding-1 (Id-1) on the proliferation and migration of human colon carcinoma cell line SW480 and HT-29. SW480 and HT-29 cells transfected with Id-1-interference sequence were assigned to the experimental groups (inhibition groups 1 and 2), and SW480 and HT-29 cells with blank interference sequence (blank groups) and blank load transfection (blank load groups) were assigned as the control groups. The expression of Id-1 in six groups was detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Cell proliferation in vitro was assessed by MTT assay. RT-PCR and Western blot results demonstrated that the mRNA and protein expressions of Id-1 in the inhibition group 1 were lower than those in the blank group 1 and blank load group 1. RT-PCR and Western blot results revealed that the mRNA and protein expressions of Id-1 were lower in the inhibition group 2 than in the blank group 2 and blank load group 2. The results of the growth curve revealed that proliferation ability was significantly weaker from the third day in the inhibition groups 1 and 2 than in the blank group and blank load group. Transwell chamber experiment and Matrigel invasion assay revealed that the number of Transwell cells significantly decreased in the inhibition groups 1 and 2 than in the blank groups and blank load groups (P < 0.01). Id-1 significantly promotes the proliferation and migration of human colon carcinoma cell lines SW480 and HT-29.

Local hyperthermia in head and neck cancer: mechanism, application and advance

Local hyperthermia (HT), particularly in conjunction with surgery, radiotherapy and chemotherapy was useful for the treatment of human malignant tumors including head and neck cancer. However, at present it suffered from many limitations such as thermal dose control, target treatment regions and discrimination between healthy and cancer cells. Recent developments in nanotechnology have introduced novel and smart therapeutic nanomaterials to local HT of head and neck cancer that basically take advantage of various targeting approaches. The aim of this paper is to give a brief review of the mechanism, methods and clinical applications of local HT in head and neck cancer, mainly focusing on photothermal therapy (PTT) and nanoparticle-based hyperthermia.

Heat shock factor 1 induces cancer stem cell phenotype in breast cancer cell lines

Heat shock factor 1 (HSF1) has long been recognized as the master transcription factor that regulates heat shock proteins (HSPs).  More recently HSF1 has been associated with a broader role in regulating response to a variety of cellular stresses beyond heat-shock.  We previously found that high HSF1 expression is associated with poor outcome in lung, breast and colon cancers. Importantly, however, the HSF1 signature correlated with poor outcome in these studies was not related to the heat shock response, which suggested that tumor outcome associated with high HSF expression may be due to processes other than stress response. Hence, we explored the question whether high HSF1 expression might be associated with the cancer stem cell (CSC) phenotype. To do so, we examined the association of HSF1 with CSC phenotype by FACS and immunofluorescence. In addition, we evaluated the effects of HSF1 over-expression and knock-down on sphere formation and CSC marker expression in breast cancer cell lines. Here, we report results demonstrating that high HSF1 not only correlates with CSC marker expression, but inducible HSF1 over-expression augments and HSF1 knock-down inhibits CSC phenotype. Furthermore, HSF1 expression confers resistance to chemotherapeutic drugs and increases CSC frequency. In conclusion, our study indicates that one of the potential HSP-independent HSF1 driven mechanisms that may contribute to poor outcome in human tumors involves regulation of the CSC phenotype. Hence, therapeutic inhibition of HSF1 may be one route to target CSCs in human tumors.

Suppressed Krüppel‑like factor 17 expression induces tumor proliferation, metastasis and a poor prognosis in papillary thyroid carcinoma

Although the role of krüppel‑like factor 17 (KLF17) in the regulation of proliferation and epithelial‑mesenchymal transition has been examined in breast and liver cancer, their effect on papillary thyroid carcinoma (PTC) remains to be elucidated. The present study aimed to investigate the expression pattern of KLF17 in PTC and the correlation between KLF17 expression and the malignant potential of PTC. KLF17 expression in PTC and adjacent liver tissues was studied by polymerase chain reaction and western blot analysis, and the association between KLF17 expression and the clinicopathological features of PTC was studied in 50 patients. By using RNA interference against KLF17, the correlation between KLF17 expression and malignant potential was examined by downregulating KLF17 expression in TPC‑1 cells, and the effects of KLF17 downregulation on cell proliferation and motility were analyzed. Furthermore, the association between KLF17 expression and the surgical outcomes of PTC patients were analyzed. Downregulated expression of KLF17 was associated with a shorter overall survival time in clinical patients (P<0.05). Low KLF17 expression was significantly associated with tumor stage, tumor size, nodal stage and metastasis stage in PTC (P<0.05). The reduced expression of KLF17 promoted the motility and proliferation ability of TPC‑1 cells by altering the expression of tight junction protein 1 and Snai1, and activating the AKT pathway by upregulating inhibitor of DNA binding 1. In conclusion, the present study demonstrated that KLF17 is important in tumor proliferation and may be a useful prognostic indicator in directing therapy. Therefore, further investigation regarding the role of KLF17 in PTC is required.

Wnt signaling as a possible promoting factor of cell differentiation in pleomorphic adenomas

There are well known that Wnt signaling was some roles of cell differentiation at the development tissues, especially the oral and maxillofacial regions of some developmental stages. Therefore, to determine Wnt signaling in the pleomorphic adenoma tissues, we examined. The expression of Wnt1 and β-catenin as well as the distribution of various cytoskeletal proteins CK7 and CK13 was examined in 30 cases of pleomorphic adenoma by immunohistochemistry. Wnt1 was detected in almost all tumor cells. The peripheral columnar cells in squamous metaplasia and small cuboidal cells in duct-like structures were strongly positive to Wnt1. Although β-catenin was clearly localized on the cell membrane of tumor cells, nuclear translocation was observed in small cuboidal cells and in some basaloid cells. The immunofluorescent staining pattern of Wnt1 and CK7 as well as Wnt1 and CK13 was consistent with IHC results. Thus, in pleomorphic adenoma, Wnt is involved in tumor cell differentiation of peripheral columnar cells forming solid nests and small peripheral columnar cells forming duct-like structures. Moreover, among the three currently known Wnt pathways, β-catenin is the suggested pathway working during cell differentiation. Furthermore, peripheral columnar cells in solid tumor nests and in squamous metaplasia are governed by another Wnt pathway other than β-catenin. Therefore, Wnt signaling through β-catenin pathway may be involved in the 'mixed' differentiation characteristic of pleomorphic adenoma although another pathway may also be possibly working in other parts of the tumor tissue.