Downregulation of selenium-binding protein 1 is associated with poor prognosis in lung squamous cell carcinoma

Nano selenium-doped TiO2 nanotube arrays on orthopedic implants for suppressing osteosarcoma growth

Osteosarcoma, the most common primary malignant bone tumor, is characterized by malignant cells producing osteoid or immature bone tissue. Most osteosarcoma patients require reconstructive surgery to restore the functional and structural integrity of the injured bone. Metal orthopedic implants are commonly used to restore the limb integrity in postoperative patients. However, conventional metal implants with a bioinert surface cannot inhibit the growth of any remaining cancer cells, resulting in a higher risk of cancer recurrence. Herein, we fabricate a selenium-doped TiO2 nanotube array (Se-doped TNA) film to modify the surface of medical pure titanium substrate, and evaluate the anti-tumor effect and biocompatibility of Se-doped TNA film. Moreover, we further explore the anti-tumor potential mechanism of Se-doped TNA film by studying the behaviors of human osteosarcoma cells in vitro. We provide a new pathway for achieving the anti-tumor function of orthopedic implants while keeping the biocompatibility, aiming to suppress the recurrence of osteosarcoma.

Withdrawal Notice

Withdrawal Notice: Zhu, Y, Pu, Q, Zhang, Q, et al. Selenium-binding protein 1 inhibits malignant progression and induces apoptosis via distinct mechanisms in non-small-cell lung cancer. Cancer Med. 2022; 00: 1-22. doi: 10.1002/cam4.5306. The above article, published online on 13th November 2022 in Wiley Online Library (https://onlinelibrary.wiley.com/doi/10.1002/cam4.5306), has been withdrawn by agreement between the journal Editor in Chief, Dr Stephen Tait, the Authors, and John Wiley & Sons, Ltd. The withdrawal has been agreed due to an editorial office error that led to the publication of the article without peer review. The revised article, which has undergone peer review may be read here: https://onlinelibrary.wiley.com/doi/10.1002/cam4.6309.

Selenium-binding protein 1 inhibits malignant progression and induces apoptosis via distinct mechanisms in non-small cell lung cancer

BACKGROUND

Selenium is an essential trace element in the human body. In epidemiological and clinical studies, Se supplementation significantly reduced the incidence of lung cancer in individuals with low baseline Se levels. The significant action of selenium is based on the selenium-containing protein as a mediator. Of note, the previous studies reported that the expression of selenium-binding protein 1 (SELENBP1) was obviously decreased in many human cancer tissues including non-small cell lung cancer (NSCLC). However, its roles in the origin and development of NSCLC are still unclear.

METHODS

The expression of SELENBP1 was measured by qRT-PCR, Western blotting and IHC in our collected clinical NSCLC tissues and cell lines. Next, the CCK-8, colony formation, wound-haeling, Millicell, Transwell, FCM assay, and in vivo xenograft model were performed to explore the function of SELENBP1 in NSCLC. The molecular mechanisms of SELENBP1 were investigated by Western blotting or IF assay.

RESULTS

We further identified that the expression of SELENBP1 was significantly decreased in NSCLC tissues in TCGA database and 45 out of 59 collected clinical NSCLC tissues compared with adjacent nontumor tissues, as well as in four NSCLC cell lines compared with normal lung cells. Particularly, we unexpectedly discovered that SELENBP1 was obviously expressed in alveolar type 2 (AT-II) cells for the first time. Then, a series of in vitro experiments uncovered that overexpression of SELENBP1 inhibited the proliferation, migration, and invasion of NSCLC cells, and induced cell apoptosis. Moreover, overexpression of SELENBP1 also inhibited growth and induced apoptosis of NSCLC cells in vivo. Mechanistically, we demonstrated that overexpression of SELENBP1 inhibited the malignant characteristics of NSCLC cells in part via inactivating the PI3K/AKT/mTOR signal pathway. Meanwhile, we found that overexpression of SELENBP1 inducing the apoptosis of NSCLC cells was associated with the activation of caspase-3 signaling pathway under nonhigh level of oxidative stress, but overexpression of SELENBP1 facilitating the cell apoptosis might be related to its combining with GPX1 and colocalizing in the nucleus under high level of oxidative stress.

CONCLUSIONS

Our findings highlighted that SELENBP1 was an important tumor suppressor during the origin and development of NSCLC. It may help to discover novel biomarkers or drug therapy targets for NSCLC.

The role of SELENBP1 and its epigenetic regulation in carcinogenic progression

The initiation and progression of cancer is modulated through diverse genetic and epigenetic modifications. The epigenetic machinery regulates gene expression through intertwined DNA methylation, histone modifications, and miRNAs without affecting their genome sequences. SELENBP1 belongs to selenium-binding proteins and functions as a tumor suppressor. Its expression is significantly downregulated and correlates with carcinogenic progression and poor survival in various cancers. The role of SELENBP1 in carcinogenesis has not been fully elucidated, and its epigenetic regulation remains poorly understood. In this review, we summarize recent findings on the function and regulatory mechanisms of SELENBP1 during carcinogenic progression, with an emphasis on epigenetic mechanisms. We also discuss the potential cancer treatment targeting epigenetic modification of SELENBP1, either alone or in combination with selenium-containing compounds or dietary selenium.

A concise review on the role of selenium for bone cancer applications

Cancer is one of the most challenging health problems in the world. Several clinical treatments have been developed, but all presenting several limitations. Among different types of cancer, bone cancer is less common, and limited new clinical treatment strategies have been proposed. Recently, a range of advanced materials has been investigated and applied for bone cancer treatment applications. However, due to the unique physiological properties of the bone tissue (a load-bearing tissue), the selection of the right type of material or the combination of suitable functional materials and base materials are critical. Selenium has been reported to present specific targeting inhibition effects on bone cancer without affecting the surrounding healthy tissue, revealing a huge potential for the development of new bone cancer treatment strategies. This paper presents a concise review on the use of selenium for bone cancer applications, discussing main synthesis methods, biocompatibility, and cytotoxicity aspects and the combination of selenium with a wide range of ceramics, metals, and polymers. Future perspectives and the novel concept of a dual-functional scaffold for both cancer treatment and new bone regeneration are also discussed.

Knockdown of annexin VII enhances nasopharyngeal carcinoma cell radiosensitivity in vivo and in vitro

BACKGROUND

Radioresistance leads to treatment failure in patients with nasopharyngeal carcinoma (NPC). Thus, enhancing the radiosensitivity of NPC cells would likely increase the effectiveness of radiotherapy. Annexin VII (Annexin A7, ANXA7) might be a tumor promoter in NPC but its functions in radiosensitivity remain unclear.

METHODS

NPC cell lines CNE2-shANXA7 and CNE2-pLKO.1 were generated and CNE2-shANXA7 nude mice xenograft tumor models were established. The main effects and molecular mechanisms of ANXA7 knockdown in NPC radiosensitivity were studied in vitro and in vivo by analyzing cell viability, clonogenicity, apoptosis, cell cycle distribution, tumor radioresponse and immunohistochemistry assay.

RESULTS

ANXA7 knockdown revealed potentially enhanced NPC cell radiosensitivity via apoptosis and increased the cell number at the G2/M phase. In the xenograft model, NPC cells with ANXA7 knockdown were dramatically sensitive to irradiation and tumor growth was significantly suppressed. Compared to CNE2-pLKO.1 xenografts, CNE2-shANXA7 showed more γ-H2AX foci and less phospho-DNA PKcs.

CONCLUSIONS

ANXA7 knockdown increased the radiosensitivity of NPC by enhancing apoptosis, modulating the cell cycle distribution into more radiosensitive phases, promoting DNA damage, and inhibiting repair. We showed that decreased ANXA7 levels enhanced radiosensitivity and provided insights into the therapeutic targets for NPC radiotherapy.

Sodium Selenite Enhanced the Anti-proliferative Effect of MEK-ERK Inhibitor in Thyroid Cancer Cells

BACKGROUND/AIM

MEK-ERK pathway plays major roles in the progression of thyroid cancer, while the use of MEK-ERK inhibitors has been limited by its toxicity. We investigated the effect of sodium selenite as an adjunct for MEK-ERK inhibitors to avoid the toxicity of ERK inhibitors.

MATERIALS AND METHODS

TPC1, 8505C and HTori-3 cells were treated with U0126 (MEK-ERK inhibitor) and cell viability was counted in the Neubauer chamber. The synergistic effects of sodium selenite and U0126 were also measured. The expression of ERK, p-ERK, and p90^RSK was determined by western blot.

RESULTS

Treatment with U0126 inhibited proliferation of TPC1 and 8505C cells in a dose-dependent manner. When 5 μM sodium selenite was added to 1 μM U0126, relative cell survival further decreased. Decreased expression of p90^RSK indicated that sodium selenite down-regulated ERK signaling in thyroid cancer cells.

CONCLUSION

The combination of U0126 and sodium selenite inhibited proliferation of thyroid cancer cells through ERK inhibition.

Differential Protein Expression between Cystic and Solid Vestibular Schwannoma Using Tandem Mass Tag-Based Quantitative Proteomic Analysis

PURPOSE

Cystic vestibular schwannoma (CVS) and solid vestibular schwannoma (SVS) are subgroups of vestibular schwannoma (VS). The tumorigenesis of CVS and SVS have not been fully elucidated, and this study is designed to identify differentially expressed proteins involved in the tumorigenesis of CVS and SVS.

EXPERIMENTAL DESIGN

Tandem mass tag-based proteomics is used to determine the protein expression profiles from CVS and SVS tissues.

RESULTS

A total of 30 differentially expressed proteins are identified between CVS and SVS, with 6 being upregulated and 24 being downregulated. Bioinformatics analyses are performed according to Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses. These results indicate that two selected proteins (COL1A1 and COL1A2) are potential biomarkers for distinguishing CVS and SVS.

CONCLUSIONS AND CLINICAL RELEVANCE

Differentially expressed proteins linked to CVS and SVS are identified, and these proteins might provide potential biomarkers for human VS diagnosis. Furthermore, the present study supports the notion that decreased collagen might be the reason for bleeding associated with CVS.

Knockdown of Annexin A1 Enhances Radioresistance and Inhibits Apoptosis in Nasopharyngeal Carcinoma

Radiotherapy is the primary treatment for nasopharyngeal carcinoma while radioresistance can hinder efficient treatment. To explore the role of annexin A1 and its potential mechanisms in radioresistance of nasopharyngeal carcinoma, human nasopharyngeal carcinoma cell line CNE2-sh annexin A1 (knockdown of annexin A1) and the control cell line CNE2-pLKO.1 were constituted and CNE2-sh annexin A1 xenograft mouse model was generated. The effect of annexin A1 knockdown on the growth of xenograft tumor after irradiation and radiation-induced DNA damage and repair was analyzed. The results of immunohistochemistry assays and Western blotting showed that the level of annexin A1 was significantly downregulated in the radioresistant nasopharyngeal carcinoma tissues or cell line compared to the radiosensitive nasopharyngeal carcinoma tissues or cell line. Knockdown of annexin A1 significantly promoted CNE2-sh annexin A1 xenograft tumor growth compared to the control groups after irradiation. Moreover, the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assays revealed that knockdown of annexin A1 significantly inhibited apoptosis in vivo compared to the control groups. We assessed the intracellular reactive oxygen species levels and the extent of radiation-induced DNA damage and repair using reactive oxygen species assay, comet assays, and immunohistochemistry assay. The results showed that knockdown of annexin A1 remarkedly reduced the intracellular reactive oxygen species levels, level of DNA double-strand breaks, and the phosphorylation level of H2AX and increased the accumulation of DNA-dependent protein kinase in nasopharyngeal carcinoma cells after irradiation. The findings suggest that knockdown of annexin A1 inhibits DNA damage via decreasing the generation of intracellular reactive oxygen species and the formation of γ-H2AX and promotes DNA repair via increasing DNA-dependent protein kinase activity and therefore improves the radioresistance in nasopharyngeal carcinoma cells. Together, our findings suggest that knockdown of annexin A1 promotes radioresistance in nasopharyngeal carcinoma and provides insights into therapeutic targets for nasopharyngeal carcinoma radiotherapy.

Robust network-based regularization and variable selection for high-dimensional genomic data in cancer prognosis

In cancer genomic studies, an important objective is to identify prognostic markers associated with patients' survival. Network-based regularization has achieved success in variable selections for high-dimensional cancer genomic data, because of its ability to incorporate the correlations among genomic features. However, as survival time data usually follow skewed distributions, and are contaminated by outliers, network-constrained regularization that does not take the robustness into account leads to false identifications of network structure and biased estimation of patients' survival. In this study, we develop a novel robust network-based variable selection method under the accelerated failure time model. Extensive simulation studies show the advantage of the proposed method over the alternative methods. Two case studies of lung cancer datasets with high-dimensional gene expression measurements demonstrate that the proposed approach has identified markers with important implications.

Selenium-Binding Protein 1 in Human Health and Disease

Selenium-binding protein 1 (SBP1) is a highly conserved protein that covalently binds selenium. SBP1 may play important roles in several fundamental physiological functions, including protein degradation, intra-Golgi transport, cell differentiation, cellular motility, redox modulation, and the metabolism of sulfur-containing molecules. SBP1 expression is often reduced in many cancer types compared to the corresponding normal tissues and low levels of SBP1 are frequently associated with poor clinical outcome. In this review, the transcriptional regulation of SBP1, the different physiological roles reported for SBP1, as well as the implications of SBP1 function in cancer and other diseases are presented.

lncRNA Gm15290 promotes cell proliferation and invasion in lung cancer through directly interacting with and suppressing the tumor suppressor miR-615-5p

Long non-coding RNAs (lncRNAs) have been involved in occurrence and progression of multiple cancers. In the present study, we investigated the role of lncRNA Gm15290 in the proliferation and invasion of non-small cell lung cancer (NSCLC) cells. First, we found that lncRNA Gm15290 was markedly up-regulated in tumor tissues from NSCLC patients and NSCLC cell lines, compared with adjacent normal tissues and normal lung cell line HBE respectively. Then, different concentrations of pcDNA-Gm15290 expression vector and Gm15290 siRNA were respectively transfected into A549 NSCLC cells. Our results showed that overexpression of Gm15290 significantly increased the proliferation and invasion of A549 cells and suppressed cell apoptosis. Knockdown of Gm15290 suppressed A549 cell proliferation and invasion and promoted cell apoptosis. Subsequently, we explored the underlying mechanism through which Gm15290 promoted cell proliferation and invasion. The output of RNA hybrid bioinformatic tool revealed that Gm15290 potentially interacted with tumor suppressor miR-615-5p which displayed an opposite expression pattern in the cell lines and a strong negative correlation with the levels of Gm15290 in NSCLC patients (r2 = 0.9677, P<0.0001). The results of RNA pull-down assays confirmed that Gm15290 directly bound with miR-615-5p Gm15290 negatively regulated the expression of miR-615-5p and increased the protein levels of miR-615-5p target genes, including IGF2, AKT2, and SHMT2 Moreover, miR-615-5p mimic could antagonize the promoting effect of Gm15290 on cell proliferation and invasion.

Eight potential biomarkers for distinguishing between lung adenocarcinoma and squamous cell carcinoma

Lung adenocarcinoma (LADC) and squamous cell carcinoma (LSCC) are the most common non-small cell lung cancer histological phenotypes. Accurate diagnosis distinguishing between these two lung cancer types has clinical significance. For this study, we analyzed four Gene Expression Omnibus (GEO) datasets (GSE28571, GSE37745, GSE43580, and GSE50081). We then imported the datasets into the Gene-Cloud of Biotechnology Information online platform to identify genes differentially expressed in LADC and LSCC. We identified DSG3 (desmoglein 3), KRT5 (keratin 5), KRT6A (keratin 6A), KRT6B (keratin 6B), NKX2-1 (NK2 homeobox 1), SFTA2 (surfactant associated 2), SFTA3 (surfactant associated 3), and TMC5 (transmembrane channel-like 5) as potential biomarkers for distinguishing between LADC and LSCC. Receiver operating characteristic curve analysis suggested that KRT5 had the highest diagnostic value for discriminating between these two cancer types. Using the PrognoScan online survival analysis tool and the Kaplan-Meier Plotter, we found that high KRT6A or KRT6B levels, or low NKX2-1, SFTA3, or TMC5 levels correlated with unfavorable prognoses in LADC patients. Further studies will be needed to verify our findings in additional patient samples, and to elucidate the mechanisms of action of these potential biomarkers in non-small cell lung cancer.

Downregulation of P38 phosphorylation correlates with low-grade differentiation and proliferation of lung squamous cell carcinoma

BACKGROUND

P38MAPK has been investigated as a tumor-related signaling molecule because of its apparent association with tumorigenesis. This study aimed to investigate P38MAPK expression and its role in lung squamous carcinoma (LSCC).

METHODS

The expression of P38MAPK and phosphorylated P38 (P-P38) in LSCC tissues and cells was examined by Western blot, real-time PCR, and immunohistochemistry. The influence of P38MAPK inhibitor SB203580 on the proliferation of LSCC cells was detected by MTT and flow cytometry.

RESULTS

The expression of P-P38 in LSCC tissues and cells was lower than that in cancer-adjacent normal tissues and normal bronchial epithelial cells (P<0.05). In addition, the expression of P-P38 was downregulated in LSCC tissues of poor differentiation, stages III and IV, and with lymph node metastasis compared with the LSCC tissues of well differentiation, stages I and II, and without lymph node metastasis (P<0.05). Moreover, the cell proliferation of LSCC SK-MES-1 cells treated by P38MAPK inhibitor SB203580 significantly increased in a concentration-dependent manner compared with that of SK-MES-1 cells without SB203580 (P<0.05). The inhibition of P38MAPK promoted the transition of the S phase to the G2 phase.

CONCLUSIONS

P-P38 was poorly expressed in LSCC tissues and cells. Its low expression was correlated with low-grade differentiation, lymph node metastasis, and advanced stage of LSCC. Inhibition of P38MAPK expression could significantly increase the proliferation of LSCC cells by promoting the transition of the S phase to the G2 phase.