Bcl-2 expression predicts radiotherapy failure in laryngeal cancer

Epigallocatechin gallate and curcumin inhibit Bcl-2: a pharmacophore and docking based approach against cancer

The protein Bcl-2, well-known for its anti-apoptotic properties, has been implicated in cancer pathogenesis. Identifying the primary gene responsible for promoting improved cell survival and development has provided compelling evidence for preventing cellular death in the progression of malignancies. Numerous research studies have provided evidence that the abundance of Bcl-2 is higher in malignant cells, suggesting that suppressing Bcl-2 expression could be a viable therapeutic approach for cancer treatment. In this study, we acquired a compound collection using a database that includes constituents from Traditional Chinese Medicine (TCM). Initially, we established a pharmacophore model and utilized it to search the TCM database for potential compounds. Compounds with a fitness score exceeding 0.75 were selected for further analysis. The Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) analysis identified six compounds with favorable therapeutic characteristics. The compounds that successfully passed the initial screening process based on the pharmacodynamic model were subjected to further evaluation. Extra-precision (XP) docking was employed to identify the compounds with the most favorable XP docking scores. Further analysis using the Molecular Mechanics Generalized Born Surface Area (MM-GBSA) method to calculate the overall free binding energy. The binding energy between the prospective ligand molecule and the target protein Bcl-2 was assessed by a 100 ns molecular dynamics simulation for curcumin and Epigallocatechin gallate (EGCG). The findings of this investigation demonstrate the identification of a molecular structure that effectively inhibits the functionality of the Bcl-2 when bound to the ligand EGCG. Consequently, this finding presents a novel avenue for the development of pharmaceuticals capable of effectively addressing both inflammatory and tumorous conditions.

Synthesis, Anticancer Activity, and In Silico Modeling of Alkylsulfonyl Benzimidazole Derivatives: Unveiling Potent Bcl-2 Inhibitors for Breast Cancer

A series of alkylsulfonyl 1H-benzo[d]imidazole derivatives were synthesized and evaluated for anticancer activity against human breast cancer cells, MCF-7 in vitro. The cytotoxic potential was determined using the xCELLigence real-time cell analysis, and expression levels of genes related to microtubule organization, tumor suppression, apoptosis, cell cycle, and proliferation were examined by quantitative real-time polymerase chain reaction. Molecular docking against Bcl-2 was carried out using AutoDock Vina, while ADME studies were performed to predict the physicochemical and drug-likeness properties of the synthesized compounds. The results revealed that compounds 23 and 27 were the most potent cytotoxic derivatives against MCF-7 cells. Gene expression analysis showed that BCL-2 was the most prominent gene studied. Treatment of MCF-7 cells with compounds 23 and 27 resulted in significant downregulation of the BCL-2 gene, with fold changes of 128 and 256, respectively. Docking analysis predicted a strong interaction between the compounds and the target protein. Interestingly, all of the compounds exhibit a higher binding affinity toward Bcl-2 than the standard drug (compound 27 vina score = -9.6 kcal/mol, vincristine = -6.7 kcal/mol). Molecular dynamics simulations of compounds 23 and 27 showed a permanent stabilization in the binding site of Bcl-2 for 200 ns. Based on Lipinski and Veber's filters, all synthesized compounds displayed drug-like characteristics. These findings suggest that compounds 23 and 27 were the most promising cytotoxic compounds and downregulated the expression of the BCL-2 gene. These derivatives could be further explored as potential candidates for the treatment of breast cancer.

Modification of BCLX pre-mRNA splicing has antitumor efficacy alone or in combination with radiotherapy in human glioblastoma cells

Dysregulation of anti-apoptotic and pro-apoptotic protein isoforms arising from aberrant splicing is a crucial hallmark of cancers and may contribute to therapeutic resistance. Thus, targeting RNA splicing to redirect isoform expression of apoptosis-related genes could lead to promising anti-cancer phenotypes. Glioblastoma (GBM) is the most common type of malignant brain tumor in adults. In this study, through RT-PCR and Western Blot analysis, we found that BCLX pre-mRNA is aberrantly spliced in GBM cells with a favored splicing of anti-apoptotic Bcl-xL. Modulation of BCLX pre-mRNA splicing using splice-switching oligonucleotides (SSOs) efficiently elevated the pro-apoptotic isoform Bcl-xS at the expense of the anti-apoptotic Bcl-xL. Induction of Bcl-xS by SSOs activated apoptosis and autophagy in GBM cells. In addition, we found that ionizing radiation could also modulate the alternative splicing of BCLX. In contrast to heavy (carbon) ion irradiation, low energy X-ray radiation-induced an increased ratio of Bcl-xL/Bcl-xS. Inhibiting Bcl-xL through splicing regulation can significantly enhance the radiation sensitivity of 2D and 3D GBM cells. These results suggested that manipulation of BCLX pre-mRNA alternative splicing by splice-switching oligonucleotides is a novel approach to inhibit glioblastoma tumorigenesis alone or in combination with radiotherapy.

Cowanin induces apoptosis in breast cancer cells via Bcl-2 signaling pathway

OBJECTIVES

This study aimed to investigate the effect of cowanin the mechanism of cowanin toward cell death and BCL-2 protein (antiapoptotic) expression of T47D breast cancer.

METHODS

The cell death was evaluated by double staining, namely acridine orange and propidium iodide, and then observed under a fluorescence microscope. Meanwhile, the BCL-2 protein expression was determined by western blotting with measurement of protein area and protein density.

RESULTS

The result found T47D breast cancer cells were viable, apoptosis, and necrosis after treatment with cowanin. The average viable cells, apoptosis, and necrosis percentages were 54.13 %, 45.43 %, and 0.44 %, respectively. Statistical analysis showed cowanin could significantly induce death in T47D breast cancer cells by apoptosis (p<0.05). It was also revealed that cowanin and positive control (doxorubicin) treatment had a significantly decreased protein area and protein density (p<0.05).

CONCLUSIONS

It can be concluded that cowanin can induce death in T47D breast cancer cells by apoptosis and affect the expression of Bcl-2 protein in T47D breast cancer cells.

Correlation of Bcl-2 Expression with Prognosis and Survival in Patients with Head and Neck Cancer: A Systematic Review and Meta-Analysis

Head and neck cancer (HNC) is a growing disease, affecting more than 700.000 cases per year and ranking as the sixth most prevalent type of cancer worldwide. The impossibility of properly entering into apoptosis directly influences uncontrolled growth and consequently tumor development and progression. Bcl-2 emerged as a key regulator in the balance between cell apoptosis and proliferation in apoptosis machinery. This systematic review and meta-analysis aimed to review all published studies investigating changes in Bcl-2 protein expression assessed by immunohistochemistry (IHC) and related to prognostic and survival values of patients with HNC. After applying the inclusion and exclusion factors, we reached the number of 20 articles included in the meta-analysis. The random-effect pooled HR (CI95%) value of OS related to Bcl-2 IHC expression in tissues from HNC patients was 1.80 (CI95% 1.21-2.67) (p < 0.0001) and DFS was 1.90 (CI95% 1.26-2.86 (p < 0.0001). The OS value for the specific oral cavity tumors was 1.89 (1.34-2.67), while in the larynx it was 1.77 (0.62-5.06), and the DFS in the pharynx was 2.02 (1.46-2.79). The univariate and multivariate analyses of OS were respectively 1.43 (1.11-1.86) and 1.88 (1.12-3.16), while in DFS it was 1.70 (0.95-3.03) and 2.08 (1.55-2.80). The OS considering a low cut-off for Bcl-2 positivity was 1.19 (0.60-2.37) and DFS was 1.48 (0.91-2.41), while studies with a high cut-off demonstrated OS of 2.28 (1.47-3.52) and DFS of 2.77 (1.74-4.40). Our meta-analysis demonstrates that Bcl-2 protein overexpression can result in worse LNM, OS, and DFS in patients with HNC, however, it is not a reliable conclusion, due to the wide divergences between the original studies and the fact that many studies have a very high range of confidence and also a high risk of bias.

Prognosis

Prognosis is defined as the likely outcome or course of a disease and is the result of a complex interplay between patient and tumor factors. Unfortunately, the prognosis of patients with laryngeal cancer has not changed significantly over the past several decades. However, as our understanding of these patient and tumor factors becomes more nuanced and the resulting treatment options become more precise, there is the potential to improve the prognosis for these patients.

Bax/Bcl-2 Cascade Is Regulated by the EGFR Pathway: Therapeutic Targeting of Non-Small Cell Lung Cancer

Non-small cell lung carcinoma (NSCLC) comprises 80%-85% of lung cancer cases. EGFR is involved in several cancer developments, including NSCLC. The EGFR pathway regulates the Bax/Bcl-2 cascade in NSCLC. Increasing understanding of the molecular mechanisms of fundamental tumor progression has guided the development of numerous antitumor drugs. The development and improvement of rationally planned inhibitors and agents targeting particular cellular and biological pathways in cancer have been signified as a most important paradigm shift in the strategy to treat and manage lung cancer. Newer approaches and novel chemotherapeutic agents are required to accompany present cancer therapies for improving efficiency. Using natural products as a drug with an effective delivery system may benefit therapeutics. Naturally originated compounds such as phytochemicals provide crucial sources for novel agents/drugs and resources for tumor therapy. Applying the small-molecule inhibitors (SMIs)/phytochemicals has led to potent preclinical discoveries in various human tumor preclinical models, including lung cancer. In this review, we summarize recent information on the molecular mechanisms of the Bax/Bcl-2 cascade and EGFR pathway in NSCLC and target them for therapeutic implications. We further described the therapeutic potential of Bax/Bcl-2/EGFR SMIs, mainly those with more potent and selectivity, including gefitinib, EGCG, ABT-737, thymoquinone, quercetin, and venetoclax. In addition, we explained the targeting EGFR pathway and ongoing in vitro and in vivo and clinical investigations in NSCLC. Exploration of such inhibitors facilitates the future treatment and management of NSCLC.

B Cell Lymphoma 2: A Potential Therapeutic Target for Cancer Therapy

Defects in the apoptosis mechanism stimulate cancer cell growth and survival. B cell lymphoma 2 (Bcl-2) is an anti-apoptotic molecule that plays a central role in apoptosis. Bcl-2 is the founding constituent of the Bcl-2 protein family of apoptosis controllers, the primary apoptosis regulators linked with cancer. Bcl-2 has been identified as being over-expressed in several cancers. Bcl-2 is induced by protein kinases and several signaling molecules which stimulate cancer development. Identifying the important function played by Bcl-2 in cancer progression and development, and treatment made it a target related to therapy for multiple cancers. Among the various strategies that have been proposed to block Bcl-2, BH3-mimetics have appeared as a novel group of compounds thanks to their favorable effects on many cancers within several clinical settings. Because of the fundamental function of Bcl-2 in the regulation of apoptosis, the Bcl-2 protein is a potent target for the development of novel anti-tumor treatments. Bcl-2 inhibitors have been used against several cancers and provide a pre-clinical platform for testing novel therapeutic drugs. Clinical trials of multiple investigational agents targeting Bcl-2 are ongoing. This review discusses the role of Bcl-2 in cancer development; it could be exploited as a potential target for developing novel therapeutic strategies to combat various types of cancers. We further highlight the therapeutic activity of Bcl-2 inhibitors and their implications for the therapeutic management of cancer.

Breaking the Silence of Tumor Response: Future Prospects of Targeted Radionuclide Therapy

Therapy-induced tumor resistance has always been a paramount hurdle in the clinical triumph of cancer therapy. Resistance acquired by tumor through interventions of chemotherapeutic drugs, ionizing radiation, and immunotherapy in the patientsis a severe drawback and major cause of recurrence of tumor and failure of therapeutic responses. To counter acquired resistance in tumor cells, several strategies are practiced such as chemotherapy regimens, immunotherapy, and immunoconjugates, but the outcome is very disappointing for the patients as well as clinicians. Radionuclide therapy using alpha or beta-emitting radionuclide as payload became state-of-the-art for cancer therapy. With the improvement in dosimetric studies, development of high-affinity target molecules, and design of several novel chelating agents which provide thermodynamically stable complexes in vivo, the scope of radionuclide therapy has increased by leaps and bounds. Additionally, radionuclide therapy along with the combination of chemotherapy is gaining importance in pre-clinics, which is quite encouraging. Thus, it opens an avenue for newer cancer therapy modalities where chemotherapy, radiation therapy, and immunotherapy are unable to break the silence of tumor response. This article describes, in brief, the causes of tumor resistance and discusses the potential of radionuclide therapy to enhance tumor response.

TFEB promotes BCL-2 expression by upregulating its promoter activity in the t(6;11) translocation renal cell carcinomas

t(6;11) translocation renal cell carcinoma (RCC) is classified as a subset of the MiT family translocation RCCs and characterized by harboring the Alpha-TFEB fusion gene. However, the development mechanism of this tumor and its effective treatment have not been fully identified yet. The purpose of this study was to explore the relationship between TFEB and BCL-2 in Alpha-TFEB stably transfected cell lines and in t(6;11) RCC tumor tissue. An Alpha-TFEB eukaryotic expression vector was constructed and stably transfected into CaKi-2 and HK-2 cells. RT-PCR and real-time RT-PCR were used to measure the mRNA expressions of TFEB and BCL-2, and immunohistochemistry, Western blot and dual immunofluorescence assays were used to evaluate the TFEB and BCL-2 protein expressions. MTT proliferation assays and flow cytometry were also performed. Furthermore, luciferase reporter assays were used to evaluate the BCL-2 promoter activity. An Alpha-TFEB eukaryotic expression vector was successfully constructed and stably transfected into CaKi-2 and HK-2 cells (named CaKi-2-TFEB and HK-2-TFEB cells). Compared with the CaKi-2 and HK-2 groups, the TFEB and BCL-2 mRNA expression levels were significantly upregulated in the CaKi-2-TFEB and HK-2-TFEB groups respectively. The TFEB and BCL-2 protein expressions showed a similar result. The overexpression of TFEB and BCL-2 promoted cell proliferation and inhibited cell apoptosis. Moreover, the overexpression of TFEB upregulated the promoter activity of BCL-2. Our data suggest that the overexpression of TFEB promotes BCL-2 expression by upregulating its promoter activity and ultimately results in the development of t(6;11) translocation RCC. BCL-2 inhibitors may serve as potential therapeutic targets for t(6;11) translocation RCC.

A Novel Approach for the Discovery of Biomarkers of Radiotherapy Response in Breast Cancer

Radiotherapy (RT) is an important treatment modality for the local control of breast cancer (BC). Unfortunately, not all patients that receive RT will obtain a therapeutic benefit, as cancer cells that either possess intrinsic radioresistance or develop resistance during treatment can reduce its efficacy. For RT treatment regimens to become personalised, there is a need to identify biomarkers that can predict and/or monitor a tumour's response to radiation. Here we describe a novel method to identify such biomarkers. Liquid chromatography-mass spectrometry (LC-MS) was used on conditioned media (CM) samples from a radiosensitive oestrogen receptor positive (ER⁺) BC cell line (MCF-7) to identify cancer-secreted biomarkers which reflected a response to radiation. A total of 33 radiation-induced secreted proteins that had higher (up to 12-fold) secretion levels at 24 h post-2 Gy radiation were identified. Secretomic results were combined with whole-transcriptome gene expression experiments, using both radiosensitive and radioresistant cells, to identify a signature related to intrinsic radiosensitivity. Gene expression analysis assessing the levels of the 33 proteins showed that 5 (YBX3, EIF4EBP2, DKK1, GNPNAT1 and TK1) had higher expression levels in the radiosensitive cells compared to their radioresistant derivatives; 3 of these proteins (DKK1, GNPNAT1 and TK1) underwent in-lab and initial clinical validation. Western blot analysis using CM samples from cell lines confirmed a significant increase in the release of each candidate biomarker from radiosensitive cells 24 h after treatment with a 2 Gy dose of radiation; no significant increase in secretion was observed in the radioresistant cells after radiation. Immunohistochemistry showed that higher intracellular protein levels of the biomarkers were associated with greater radiosensitivity. Intracellular levels were further assessed in pre-treatment biopsy tissues from patients diagnosed with ER⁺ BC that were subsequently treated with breast-conserving surgery and RT. High DKK1 and GNPNAT1 intracellular levels were associated with significantly increased recurrence-free survival times, indicating that these two candidate biomarkers have the potential to predict sensitivity to RT. We suggest that the methods highlighted in this study could be utilised for the identification of biomarkers that may have a potential clinical role in personalising and optimising RT dosing regimens, whilst limiting the administration of RT to patients who are unlikely to benefit.

Biomarkers of laryngeal squamous cell carcinoma: a review

Laryngeal carcinoma is the second common malignancy of the upper aerodigestive tract after lung cancer; in most cases is a squamous cell carcinoma, whose risk factors include tobacco smoking and alcohol consumption. Despite therapeutic progress, the five-year overall survival rate for this malignancy has remained nearly 50% and many patients already present metastasis at the time of diagnosis. To date, there are no tools that predict the evolution of laryngeal carcinoma: in this light, during the last years, many studies were planned with the aim to investigate the role played by different biomarkers expressed by larynx cancer, which can help make an early diagnosis, predict disease evolution and direct therapeutic choice. This review aims to summarize these markers and correlating them with disease evolution.

Targeting Stress-Response Pathways and Therapeutic Resistance in Head and Neck Cancer

Head and neck cancer is the sixth leading cancer worldwide; head and neck squamous cell carcinoma (HNSCC) accounts for more than 90% of incident cases. In the US, cases of HNSCC associated with human papillomavirus (HPV) have been growing in proportion amongst a younger demographic with superior outcomes to the same treatments, relative to cases associated with tobacco. Yet failures to improve the long-term prognosis of advanced HNSCC over the last three decades persist in part due to intrinsic and acquired mechanisms of resistance. Deregulation of the pathways to respond to stress, such as apoptosis and autophagy, often contributes to drug resistance and tumor progression. Here we review the stress-response pathways in drug response and resistance in HNSCC to explore strategies to overcome these resistance mechanisms. We focus on the mechanisms of resistance to current standard cares, such as chemotherapy (i.e., cisplatin), radiation, and cetuximab. Then, we discuss the strategies to overcome these resistances, including novel combinations and immunotherapy.

Aberrant Bcl-x splicing in cancer: from molecular mechanism to therapeutic modulation

Bcl-x pre-mRNA splicing serves as a typical example to study the impact of alternative splicing in the modulation of cell death. Dysregulation of Bcl-x apoptotic isoforms caused by precarious equilibrium splicing is implicated in genesis and development of multiple human diseases, especially cancers. Exploring the mechanism of Bcl-x splicing and regulation has provided insight into the development of drugs that could contribute to sensitivity of cancer cells to death. On this basis, we review the multiple splicing patterns and structural characteristics of Bcl-x. Additionally, we outline the cis-regulatory elements, trans-acting factors as well as epigenetic modifications involved in the splicing regulation of Bcl-x. Furthermore, this review highlights aberrant splicing of Bcl-x involved in apoptosis evade, autophagy, metastasis, and therapy resistance of various cancer cells. Last, emphasis is given to the clinical role of targeting Bcl-x splicing correction in human cancer based on the splice-switching oligonucleotides, small molecular modulators and BH3 mimetics. Thus, it is highlighting significance of aberrant splicing isoforms of Bcl-x as targets for cancer therapy.

Radiation Resistance: A Matter of Transcription Factors

Currently, radiation therapy is one of the standard therapies for cancer treatment. Since the first applications, the field of radiotherapy has constantly improved, both in imaging technologies and from a dose-painting point of view. Despite this, the mechanisms of resistance are still a great problem to overcome. Therefore, a more detailed understanding of these molecular mechanisms will allow researchers to develop new therapeutic strategies to eradicate cancer effectively. This review focuses on different transcription factors activated in response to radiotherapy and, unfortunately, involved in cancer cells’ survival. In particular, ionizing radiations trigger the activation of the immune modulators STAT3 and NF-κB, which contribute to the development of radiation resistance through the up-regulation of anti-apoptotic genes, the promotion of proliferation, the alteration of the cell cycle, and the induction of genes responsible for the Epithelial to Mesenchymal Transition (EMT). Moreover, the ROS-dependent damaging effects of radiation therapy are hampered by the induction of antioxidant enzymes by NF-κB, NRF2, and HIF-1. This protective process results in a reduced effectiveness of the treatment, whose mechanism of action relies mainly on the generation of free oxygen radicals. Furthermore, the previously mentioned transcription factors are also involved in the maintenance of stemness in Cancer Stem Cells (CSCs), a subset of tumor cells that are intrinsically resistant to anti-cancer therapies. Therefore, combining standard treatments with new therapeutic strategies targeted against these transcription factors may be a promising opportunity to avoid resistance and thus tumor relapse.

Intrinsic and extrinsic pathways of apoptosis: Role in cancer development and prognosis

Apoptosis, also named programmed cell death, is a fundament process required for morphogenetic homeostasis during early development and in pathophysiological conditions. It is come into existence in 1972 by work of Kerr, Wyllie and Currie and later on investigated during the research on development of the C. elegans. Trigger by several stimuli, apoptosis is necessary during the embryonic development and aging as homeostatic mechanism to control the cell population and also play a key role as defense mechanism against the immune responses and elimination of damaged cells. Cancer, a genetic disease, is a growing burden on the health and economy of both developing and developed countries. Every year there is tremendously increasing in the number of new cancer cases and mortality rate. Although, there is a significant improvement have been made in biotechnological and bioinformatic fields however, the therapeutic advantages and cancer etiology is still under explored. Several studies determined the deregulation of different apoptotic components during the cancer development and progression. Apoptosis relies on activation of distinct signaling pathways that are often deregulated in cancer. Thus, exploring the single or more than one apoptotic component underlying their expression in carcinogenesis could help to track the disease progression. Current book chapter will provide the several evidences supporting the use of different apoptotic components as prognosis and prediction markers in various human cancer types.

Early glottic cancer recurrence: A critical review on its current management

INTRODUCTION

Recurrent early glottic cancer (rEGC) poses several issues in terms of timely diagnosis, correct re-staging, and treatment. We want to critically review the latest evidence about rEGC considering its epidemiology, biology, diagnostic challenges, and treatment strategies.

METHODS

A systematic search of the literature using PubMed from 1990 to October 31, 2020 was performed.

RESULTS

There are many different treatment options available (open surgery, transoral mini-invasive surgery, radiotherapy), and many factors related to the patient's status and previous treatments must be considered when planning the best management strategy for rEGC. While its overall prognosis remains satisfactory, it is of the utmost importance to appreciate all the clinical implications derived from the choice of the initial therapeutic modality, and from a correct primary and recurrent staging.

CONCLUSION

The balance between oncological and voice and swallowing functions represents the fundamental principle underlying rEGC management. Future studies should focus on molecular profiling of rEGC, and on the results of the emerging radiation delivery techniques and mini-invasive procedures.

Long non-coding RNA MIAT promotes the proliferation and invasion of laryngeal squamous cell carcinoma cells by sponging microRNA-613

Accumulating evidence indicates that the long non-coding RNA myocardial infarction associated transcript (lncRNA MIAT) serves an important role in the progression of a number of cancer types. However, the precise molecular mechanism of MIAT in laryngeal squamous cell carcinoma (LSCC) progression remain elusive. The aim of the current study was to assess the effects and to clarify the molecular mechanism of MIAT on the proliferation and invasion of LSCC cells. The expression of MIAT was detected in LSCC tissues and cells using reverse transcription-quantitative PCR. MTT and colony formation assays were performed to examine the effects of MIAT on the proliferation of LSCC cells. Additionally, wound healing and Transwell experiments were employed to examine cellular migration and invasion. Luciferase reporter gene assay was also used to confirm the direct binding between MIAT and microRNA (miR)-613 in LSCC cells. An RNA immunoprecipitation assay was performed to verify the interaction between MIAT and miR-613. In the present study, it was found that the expression of MIAT in LSCC tissues was markedly higher compared with that in adjacent non-tumor tissues. In addition, MIAT expression was also increased in the human LSCC cell lines TU686, TU-177 and AMC-HN-8 compared with that in normal human keratinocytes (HaCaT). Knocking down MIAT expression significantly reduced LSCC cell proliferation and inhibited colony formation, a shown by MTT and colony formation assays, respectively. MIAT knockdown also substantially inhibited the migratory and invasive abilities of LSCC cells, as shown by wound healing and Transwell invasion assays, respectively. Subsequently, luciferase reporter assays verified that MIAT could bind to miR-613, where a negative correlation was observed between the expression of MIAT and miR-613 in LSCC tissues. Suppression of miR-613 partially reversed the inhibitory effects of MIAT knockdown on the proliferation, migration and invasion of LSCC cells. Taken together, the present study identified that MIAT may function as an oncogenic lncRNA to promote LSCC progression, which provides a potential therapeutic target or as a novel diagnostic biomarker for LSCC.

The future potential of Annona muricata L. extract and its bioactive compounds as radiation sensitizing agent: proposed mechanisms based on a systematic review

Despite technological advances in cancer treatment, especially in radiotherapy, many efforts are being made in improving cancer cell radio-sensitivity to increase therapeutic ratio and overcome cancer cell radio-resistance. In the present review, we evaluated the anticancer mechanism of Annona muricata L. (AM) leaves extract and its bioactive compounds such as annonaceous acetogenins, annomuricin, annonacin, or curcumin; and further correlated them with the potential of the mechanism to increase or to reduce cancer cells radio-sensitivity based on literature investigation. We see that AM has a promising future potential as a radio-sensitizer agent.

Biological tumor markers associated with local control after primary radiotherapy in laryngeal cancer: A systematic review

BACKGROUND

The choice of treatment in laryngeal cancer is mainly based on tumor stage, post-treatment morbidity and quality of life. Biological tumor markers might also be of potential clinical relevance.

OBJECTIVE OF THE REVIEW

The aim was to systematically review the value of published biological tumor markers to predict local control in laryngeal cancer patients treated with definitive radiotherapy.

TYPE OF REVIEW

Systematic review.

SEARCH STRATEGY

PubMed, Embase, Cochrane Library.

EVALUATION METHOD

A literature search was performed using multiple terms for laryngeal cancer, radiotherapy, biological markers, detection methods and local control or survival. Studies regarding the relation between biological tumor markers and local control or survival in laryngeal cancer patients primarily treated with radiotherapy were included. Markers were clustered on biological function. Quality of all studies was assessed. Study selection, data extraction and quality assessment was performed by two independent reviewers.

RESULTS

A total of 52 studies out of 618 manuscripts, concerning 118 markers, were included. EGFR and P53 showed consistent evidence for not being predictive of local control after primary radiotherapy, whereas proliferation markers (ie high Ki-67 expression) showed some, but no consistent, evidence for being predictive of better local control. Other clusters of markers (markers involved in angiogenesis and hypoxia, apoptosis markers, cell cycle, COX-2 and DNA characteristics) showed no consistent evidence towards being predictors of local control after primary radiotherapy.

CONCLUSIONS

Cell proliferation could be of potential interest for predicting local control after primary radiotherapy in laryngeal cancer patients, whereas EGFR and p53 are not predictive in contrast to some previous analyses. Large diversity in research methods is found between studies, which results in contradictory outcomes. Future studies need to be more standardised and well described according to the REMARK criteria in order to have better insight into which biomarkers can be used as predictors of local control after primary radiotherapy.

The role of CD133 expression of cancer stem cells on radiotherapy response in early stage glottic cancers

PURPOSE

To investigate the relationship between CD133 positivity and radiotherapy (RT) response in early stage glottic laryngeal cancers.

METHODS

Thirty seven patients with early-stage glottic laryngeal carcinoma who were treated with primary RT were evaluated. Patients with regular follow-up of at least 3 years were included in the study. Patients who had previously received chemotherapy for laryngeal surgery or underwent surgery were excluded. The patients were divided into two groups as recurrent and non-recurrent. These two groups were compared in terms of CD133 expression by immunohistochemical method.

RESULTS

There were 37 patients in the study. Ten patients had recurrence and seven (70%) had CD133 positive and three had CD133 negative. Of 27 patients who had no recurrence, 16 (59%) had CD133 positive and 11 (41%) had CD133 negative. 7 (70%) of ten patients with recurrence were found to be positive for CD133; There was no statistically significant difference between recurrent and non-recurrent patient groups in terms of CD133 positivity (p > 0.05). There was no correlation between the final CD133 score and recurrence status as well (p > 0.05).

CONCLUSION

There was no relationship between radiotherapy response and CD133 staining in early-stage glottic laryngeal cancers. It is the largest study about CD133 and RT sensitivity in early stage glottic carcinomas.

UBR5 regulates proliferation and radiosensitivity in human laryngeal carcinoma via the p38/MAPK signaling pathway

Laryngeal carcinoma (LCC) is a common malignant tumor with low radiosensitivity and generally poor response rates. The ubiquitin protein ligase E3 component n-recognin 5 (UBR5) has prognostic implications in several neoplasms; however, its role in LCC and radiotherapy sensitivity remains unknown. Immunohistochemistry and bioinformatics analyses were performed to measure UBR5 protein and mRNA expression in LCC and adjacent non-tumor tissues. The gene and protein expression of UBR5 in LCC and HuLa-PC cell lines were measured using quantitative PCR and western blot analyses. Following transfection with small interfering RNA or UBR5 overexpression plasmid in LCC cells, the proliferation, cell cycle distribution, invasion, migration and radiosensitivity of LCC cells were analyzed. UBR5-related lncRNA, targeted miRNA and protein-protein interaction networks were analyzed using bioinformatics. Finally, the expression of the p38/mitogen-activated protein kinase (MAPK) pathway was evaluated following UBR5 silencing in M2E cells treated with radiation. Increased UBR5 expression was observed in LCC tissues compared with adjacent non-tumor tissues, and it was correlated with poor overall survival of LCC patients. After overexpression or silencing of UBR5 in M2E and M4E LCC cells, cell proliferation and radiosensitivity were significantly increased or decreased, respectively, compared with the control groups. The percentage of S phase cells decreased in the UBR5 si-RNA group compared with that in the control group, while overexpression of UBR5 exerted no effect on the cell cycle. In addition, the expression of Bcl-2 and p38 was decreased in the si-UBR5 combined with radiation groups. The level of phosphorylated p38 expression was increased after combination of si-UBR5 with radiation. The small molecule inhibitor of p38/MAPK signaling, SB203580, decreased the viability of UBR5-overexpressing cells and the survival fraction when cells were exposed to radiation. These findings demonstrated that UBR5 may be involved in regulating cell proliferation and sensitivity to radiotherapy in LCC via the p38/MAPK pathway, thereby highlighting its possible value for the development of new therapeutic strategies and targets for the treatment of this disease.

Positive BCL2L12 expression predicts favorable prognosis in patients with laryngeal squamous cell carcinoma

BACKGROUND

Laryngeal squamous cell carcinoma (LSCC) constitutes the third most frequent head and neck cancer. Several tissue biomarkers have been studied for their prognostic significance in LSCC.

OBJECTIVE

To investigate the prognostic significance of BCL2L12, a new member of the BCL2 family, in primary LSCC along with well-examined biomarkers such as BCL2 and BAX.

METHODS

Cancerous tissue specimens of patients with primary LSCC were collected during 2005 and 2012 as pretreatment tissue biopsy. The specimens were immunohistochemically evaluated for the protein expression of BCL2L12, BCL2 and BAX. Kaplan-Meier survival curves and Cox proportional hazard regression models were performed to evaluate prognosis.

RESULTS

In the study cohort of 78 patients with primary LSCC, Kaplan-Meier survival curves demonstrated that advanced-stage LSCC patients with BCL2L12-positive tumors had significantly higher OS time in comparison with advanced-stage LSCC patients with BCL2L12-negative tumors (p= 0.014). Also, advanced-stage LSCC patients with BCL2L12-positive tumors had significantly lower risk of death from LSCC compared to advanced-stage LSCC patients with BCL2L12-negative tumors (HR = 0.228, 95%CI = 0.063-0.833, p= 0.025).

CONCLUSIONS

BCL2L12 protein expression could be used as a favorable prognostic tissue biomarker in patients with primary advanced-stage LSCC. On the contrary, BCL2 and BAX did not correlate with prognosis in patients with primary LSCC.

Adaptive Responses to Monotherapy in Head and Neck Cancer: Interventions for Rationale-Based Therapeutic Combinations

Most Phase II and III clinical trials in head and neck cancer (HNC) combine two or more treatment modalities, which are based, in part, on knowledge of the molecular mechanisms of innate and acquired resistance to monotherapy. In this review, we describe the range of tumor-cell autonomously derived (intrinsic) and tumor-microenvironment-derived (extrinsic) acquired-resistance mechanisms to various FDA-approved monotherapies for HNC. Specifically, we describe how tumor cells and the tumor microenvironment (TME) respond to radiation, chemotherapy, targeted therapy (cetuximab), and immunotherapies [programmed cell death 1 (PD-1) inhibitors] and adapt to the selective pressure of these monotherapies. Due to the diversity of adaptive responses to monotherapy, monitoring the response to treatment in patients is critical to understand the path that leads to resistance and to guide the optimal therapeutic drug combinations in the clinical setting. We envisage that applying such a rationale-based therapeutic strategy will improve treatment efficacy in HNC patients.

Reprogramming of Energy Metabolism in Response to Radiotherapy in Head and Neck Squamous Cell Carcinoma

Head and neck cancer (HNC) is the sixth cause of cancer-related death worldwide. Head and neck squamous cells carcinoma (HNSCC) is the most frequent subtype of HNC. The development of HNSCC is associated to alcohol consumption, smoking or infection by high-risk human Papillomavirus (HR-HPV). Although the incidence of cancers associated with alcohol and tobacco has diminished, HNSCC associated with HR-HPV has significantly increased in recent years. However, HPV-positive HNSCC responds well to treatment, which includes surgery followed by radiation or chemoradiation therapy. Radiation therapy (RT) is based on ionizing radiation (IR) changing cell physiology. IR can directly interact with deoxyribonucleic acid (DNA) or produce reactive oxygen and nitrogen species (RONS), provoking DNA damage. When DNA damage is not repaired, programmed cell death (apoptosis and/or autophagy) is induced. However, cancer cells can acquire resistance to IR avoiding cell death, where reprogramming of energy metabolism has a critical role and is intimately connected with hypoxia, mitochondrial physiology, oxidative stress (OS) and autophagy. This review is focused on the reprogramming of energy metabolism in response to RT in HPV-positive and HPV-negative HNSCC, showing their differences in cellular metabolism management and the probable direction of treatments for each subtype of HNSCC.

MiR-196b affects the progression and prognosis of human LSCC through targeting PCDH-17

OBJECTIVE

To explore the effect of miR-196bon the biological features of human laryngeal squamous cell carcinoma (LSCC) through targeting PCDH-17.

METHODS

miR-196b and PCDH-17 expressions were determined in tissues, and the targeting relation of miR-196b and PCDH-17 was verified through dual-luciferase reporter system. In vitro, Hep-2 cells were divided into the Control, miR-196b inhibitors, miR-NC, PCDH-17, and miR-196b mimics+PCDH-17 groups. The miR-196b and PCDH-17 expressions were determined by qRT-PCR or/and Western blot, and the biological features by MTT, Annexin V-FITC/PI, wound-healing and Transwell assays.

RESULTS

MiR-196b was found to be up-regulated, while PCDH-17 was down-regulated in a negative correlation in LSCC patients, which was related to histological grade and TNM stage. And low expression of miR-196b and high expression of PCDH-17 contributed to an increase in the 5-year-survival rate of LSCC patients. Besides, miR-196b directly targeted PCDH-17, while miR-196b inhibitors could up-regulate the PCDH-17 in Hep-2 cells. Moreover, miR-196b inhibitors and PCDH-17 curbed Hep-2 cell proliferation but facilitated the apoptosis, with decreases in cell invasion and migration. In addition, no statistical significance was found in cell proliferation, apoptosis, invasion and migration between Control group and miR-196b mimics+PCDH-17 group.

CONCLUSION

LSCC patients exhibited the up-regulated miR-196b and down-regulated PCDH-17, which are correlated with the major clinical features and prognosis. Inhibiting miR-196b may suppress proliferation, migration and invasion abilities, and promote apoptosis of Hep-2 cells via targeting PCDH-17.

Precision Therapy of Head and Neck Squamous Cell Carcinoma

Precision medicine is an approach to disease prevention and treatment that takes into account genetic variability and environmental and lifestyle influences that are unique to each patient. It facilitates stratification of patient populations that vary in their susceptibility to disease and response to therapy. Shared databases and the implementation of new technology systems designed to advance the integration of this information will enable health care providers to more accurately predict and customize prevention and treatment strategies for patients. Although precision medicine has had a limited impact in most areas of medicine, it has been shown to be an increasingly successful approach to cancer therapy. Despite early promising results targeting aberrant signaling pathways or inhibitors designed to block tumor-driven processes such as angiogenesis, limited success emphasizes the need to discover new biomarkers and treatment targets that are more reliable in predicting response to therapy and result in better health outcomes. Recent successes in the use of immunity-inducing antibodies have stimulated increased interest in the use of precision immunotherapy of head and neck squamous cell carcinoma. Using next-generation sequencing, the precise profiling of tumor-infiltrating lymphocytes has great promise to identify hypoimmunogenic cancer that would benefit from a rationally designed combinatorial approach. Continued interrogation of tumors will reveal new actionable targets with increasing therapeutic efficacy and fulfill the promise of precision therapy of head and neck cancer.

The evaluation of bcl-2 expression as a prognostic marker in early stage laryngeal cancer

Aims and background

To evaluate the effect of bcl-2 expression on the local control and overall survival of patients with early stage laryngeal cancer treated with radiotherapy alone.

Methods and study design

We included 53 patients with stage Tis, T1, and T2 laryngeal cancer who were irradiated in our department. Paraffin blocks of all biopsy specimens were subjected to immunohistochemical analysis with a bcl-2 oncoprotein mouse clone 124 Scytek kit.

Results

The mean follow-up time was 61 months (range, 7–166). Local-regional recurrence was observed in 10 (19%) patients. Forty-three patients (81%) had negative bcl-2 staining, 5 patients (9%) had + staining, 3 patients (6%) ++ staining, and 2 patients (4%) +++ staining. No relationship was detected between bcl-2 expression and local control or overall survival. The emergence of a recurrence and a younger age (<50 years) were significantly related to poor overall survival (P = 0.000 and P = 0.021, respectively). Patients with hemoglobin levels in the middle of radiotherapy and at the end of radiotherapy higher than 13 g/dl had improved overall survival in multivariate analyses (P = 0.002 and P = 0.001, respectively). Regarding local control, the following were poor prognostic factors: smoking more than 20 cigarettes a day (P = 0.001) and being younger than 50 years of age (P = 0.001).

Conclusions

No correlation was observed between bcl-2 expression and local control or overall survival. Whereas hemoglobin level, age and existence of a recurrence had a prognostic impact on overall survival, patient age and smoking status influenced local control rates.

Radiotherapy-Associated Long-term Modification of Expression of the Inflammatory Biomarker Genes ARG1, BCL2L1, and MYC

Ionizing radiation (IR) exposure of cells in vitro and in vivo triggers a complex cellular response among which modifications of gene expression have been consistently reported. Nevertheless, little is currently known about the transcriptionally responsive genes which play a role in the inflammation response. In order to improve our understanding of such transcriptional response to radiation in vivo, we simultaneously monitored the expression of 249 genes associated with the inflammation response over the course of the radiotherapy treatment in blood of patients treated for endometrial or head and neck cancer. We have identified genes whose transcriptional expression is either upregulated (ARG1, BCL2L1) or downregulated (MYC) several fold in vivo. These modifications were consistently detected across patients and further confirmed by quantitative real-time polymerase chain reaction (QRT-PCR); they were specifically significant toward the end of the radiotherapy treatment, 5 weeks following the first radiation fraction and more pronounced in endometrial patients (respectively, 2.9, 4.1, and 1.8 times). Importantly, in an attempt to correlate expression levels with normal tissue reaction to IR, we also identified three other genes CD40, OAS2, and CXCR1 whose expression level fluctuations during radiotherapy were more pronounced in patients developing late normal tissue responses to curative radiotherapy after the end of the radiotherapy treatment. Overall, we identified inflammation-associated genes which are promising biomarkers of IR exposure and susceptibility to radiation-induced toxicity.

Overcoming radioresistance in head and neck squamous cell carcinoma

Radiation therapy plays an essential role in the treatment of head and neck squamous cell carcinoma (HNSCC), yet therapeutic efficacy is hindered by treatment-associated toxicity and tumor recurrence. In comparison to other cancers, innovation has proved challenging, with the epidermal growth factor receptor (EGFR) antibody cetuximab being the only new radiosensitizing agent approved by the FDA in over half a century. This review examines the physiological mechanisms that contribute to radioresistance in HNSCC as well as preclinical and clinical data regarding novel radiosensitizing agents, with an emphasis on those with highest translational promise.

High BAX/BCL2 mRNA ratio predicts favorable prognosis in laryngeal squamous cell carcinoma, particularly in patients with negative lymph nodes at the time of diagnosis

OBJECTIVES

Laryngeal squamous cell carcinoma (LSCC), a common type of head and neck cancer, is associated with high rates of metastasis and recurrence. Therefore, accurate prognostic stratification of LSCC patients based on molecular prognostic tumor biomarkers would definitely lead to a better clinical management of this malignancy. The aim of this study was the investigation of the potential combinatorial prognostic value of BCL2 and BAX mRNA expression in LSCC.

DESIGN AND METHODS

Total RNA was isolated from 105 cancerous laryngeal tissue specimens obtained from patients having undergone surgical treatment for primary LSCC. After cDNA preparation, a low-cost, in-house developed, sensitive and accurate real-time quantitative PCR (qPCR) methodology was applied for the quantification of BCL2 and BAX mRNA levels. Then, we carried out a biostatistical analysis to assess the prognostic value of the BAX/BCL2 mRNA expression ratio.

RESULTS

High BAX/BCL2 mRNA expression constitutes a favorable prognosticator in LSCC, predicting significantly longer disease-free survival (P=0.011) and overall survival (P=0.014) of patients. More importantly, the significant prognostic value of the BAX/BCL2 mRNA expression appeared to be independent of the histological grade and size of the malignant laryngeal tumor as well as TNM stage, as revealed by the multivariate bootstrap Cox regression analysis. Kaplan-Meier survival analysis demonstrated also that the BAX/BCL2 ratio can stratify node-negative (N0) LSCC patients into two subgroups with significantly different DFS and OS (P=0.021 and P=0.009, respectively).

CONCLUSIONS

The BAX/BCL2 mRNA ratio is a putative molecular tissue biomarker in CLL and hence deserves further validation in larger cohorts of LSCC patients.

Inhibiting GLUT-1 expression and PI3K/Akt signaling using apigenin improves the radiosensitivity of laryngeal carcinoma in vivo

Hypoxia is an important factor in radioresistance of laryngeal carcinoma. Glucose transporter-1 (GLUT-1) is an important hypoxic marker in malignant tumors, including laryngeal carcinoma. Apigenin is a natural phytoestrogen flavonoid that has potential anticancer effects. Various studies have reported that the effects of apigenin on lowering GLUT-1 expression were involved in downregulation of the PI3K/Akt pathway. Thus, apigenin may improve the radiosensitivity of laryngeal carcinoma by suppressing the expression of GLUT-1 via the PI3K/Akt pathway. The effect of GLUT-1 and PI3K/Akt pathway-related factor expressions by apigenin or antisense oligonucleotides (AS-ODNs) on the radiosensitivity of laryngeal carcinoma in vivo was assessed. The xenograft volume, xenograft weight and apoptosis detection were performed to determine radiosensitivity. The results showed that apigenin or apigenin plus GLUT-1 AS-ODNs improved the radiosensitivity of xenografts. Apigenin or apigenin plus GLUT-1 reduced the expression of GLUT-1, Akt, and PI3K mRNA after X-ray radiation. We found similar results at the protein level. The results suggest that the effects of apigenin on inhibiting xenograft growth and enhancing xenograft radiosensitivity may be associated with suppressing the expression of GLUT-1 via the PI3K/Akt pathway. In addition, apigenin may enhance the effects of GLUT-1 AS-ODNs via the same mechanism.

Effective Biomarkers and Radiation Treatment in Head and Neck Cancer

CONTEXT

Radiation is a key arm in the multidisciplinary treatment of patients with head and neck squamous cell carcinoma. During the past 2 decades, significant changes in the way radiation therapy is planned and delivered have improved efficacy and decreased toxicity. Refined approaches in the application of radiation and chemoradiation have led to organ-sparing treatment regimens for laryngeal and pharyngeal cancers and have improved local and regional control rates in the postoperative, adjuvant setting. The molecular and genetic determinants of tumor cell response to radiation have been studied, and several potential biomarkers are emerging that could further improve application and efficacy of radiation treatment in head and neck squamous cell carcinoma.

OBJECTIVE

To discuss the current understanding of potential biomarkers related to radiation response in head and neck squamous cell carcinoma.

DATA SOURCES

Existing published literature.

CONCLUSIONS

Several potential biomarkers are actively being studied as predictors and targets to improve the use and efficacy of radiation therapy to treat head and neck squamous cell carcinoma. Several promising candidates have been defined, and new markers are on the horizon.

Prognostic value of Bcl-2 expression in squamous cell carcinoma of the larynx: a systematic review

The aim of this systematic review was to determine the prognostic value of Bcl-2 immunostaining in patients affected by laryngeal squamous cell carcinoma. An appropriate search was conducted on PubMed to retrieve articles dealing with this topic. A double cross-check was performed on citations and full-text articles by 2 investigators independently to review all manuscripts and perform a comprehensive quality assessment. Of 115 abstracts identified, 15 articles were included. These studies reported on 1,150 patients with histologically confirmed diagnosis of laryngeal squamous cell carcinoma. Only a few studies showed a statistical correlation between Bcl-2 immunohistochemical expression and at least 1 of the clinical and histopathological parameters considered by the authors. Moreover, these findings were also discordant between them. Overall the studies analyzed suggested that Bcl-2 expression was statistically connected with N stage (2/14), grading (2/14), disease-free survival (3/14) and overall survival (5/14). Interestingly, all of the 3 studies investigating the relation between Bcl-2 and radioresistance showed significant results in terms of recurrence-free survival and overall survival. Our review strongly suggests that the immunohistochemical staining of Bcl-2 does not correlate with tumoral aggressiveness and prognosis of patients affected by laryngeal squamous cell carcinoma and treated with primary surgery. However, an interesting connection of this protein could be demonstrated with tumoral radioresistance. Further, high-quality prospective studies should be carried out to confirm this hypothesis.

Different protein expression associated with chemotherapy response in oropharyngeal cancer according to HPV status

BACKGOUND

Oropharyngeal cancer (OPC) associated with human papilloma virus (HPV OPC) shows better treatment outcomes than non-HPV OPC. We investigated the expression of p53, β-tubulin, bcl-2 and ERCC 1, which are well-known biomarkers to predict the chemotherapy response, according to HPV status in OPC patients.

METHODS

Patients who treated with at least 2 cycles of induction chemotherapy followed by concurrent chemoradiotherapy for locally advanced oropharyngeal cancer were reviewed. HPV PCR and immunohistochemical stain was done in paraffin embedded tumor tissue and evaluated the relation with the chemotherapy response and survival outcomes according to HPV status.

RESULTS

Seventy-four patients were enrolled for this study and all patients received induction chemotherapy with docetaxel, 5-FU and cisplatin. After induction chemotherapy, complete response (CR) was shown in 22 patients (30%) and partial response (PR) in 46 patients (62%). HPV + was detected in 21 patients (28%), while 35 patients (47%) showed p16+ expression by IHC analysis. p16 positive patients showed better overall response, PFS and OS than p16 negative patients. p53 and class III beta-tubulin expression were significantly higher in HPV- and p16- than HPV + and p16+ patients. Conversely, bcl-2 expression was greater in HPV + or p16+ than HPV- or p16- patients. ERCC1 expression did not differ significantly according to HPV status. In multivariate analyses, early T stage (p = 0.036) and good PS (PS 0) (p = 0.029) showed a better 3Y-PFS rate, and low p53 expression (p = 0.012) and complete response after induction chemotherapy (p = 0.026) were highly associated with 3Y-OS rate. Low expression of p53 and p16 positive patients showed significantly prolonged OS than others (p = 0.010).

CONCLUSION

P53, class III beta-tubulin and bcl-2 were differently expressed in OPC according to HPV status and present study suggested the underlying mechanism of better response to chemotherapy in case of HPV OPC than non-HPV OPC. Among these biomarkers, p53 is the strongest prognostic marker in OPC and p53 in addition to p16 support the rationale to study of de-escalation strategy for OPC.

Bcl-xL overexpression and its association with the progress of tongue carcinoma

Apoptosis-related protein B-cell lymphoma-extra large (Bcl-xL) has a crucial role in the control of cell death through its inhibition of apoptosis. This study was designed to investigate the expression of Bcl-xL in relation to the development of tongue carcinoma and whether it has potential as a marker for the clinical diagnosis of tongue carcinoma and as a therapeutic target to evaluate the dynamic of tongue carcinoma progression. A statistical analysis of 100 cases oral tongue carcinoma tissue specimens were performed using pathological grading and clinical TNM staging, and 14 cases corresponding non-tumor tissues as control. The changes in Bcl-xL mRNA expression between different pathological grades and clinical TNM stages of tissue were analyzed by RT-PCR. Additionally, immunohistochemical SP method and Western blot assays were employed to detect changes in Bcl-xL protein expression in different tongue carcinoma tissues. The results showed the expression of Bcl-xL was significantly higher in tongue carcinoma tissues than in normal tongue tissues and was positively associated with the degree of differentiation and the clinical TNM staging, but negatively correlated with the degree of malignancy of the tumor. There was higher expression of Bcl-xL in oral tongue squamous cell carcinoma (OTSCC) tissues compared with oral tongue adenocarcinoma (OTA) tissues, but Bcl-xL expression in tissue with lymph node metastasis was significantly higher than that without lymph node metastasis. Thus, Bcl-xL overexpression may be closely related to the dynamic of the pathogenesis and development of tongue carcinoma. It may be a useful marker for clinical diagnosis and an aid to evaluating the efficacy of therapeutics in tongue carcinoma.

A novel panel of biomarkers predicts radioresistance in patients with squamous cell carcinoma of the head and neck

PURPOSE

Global gene expression analysis was performed on pre-treatment biopsies from patients with squamous cell carcinoma of the head and neck (SCCHN) to discover biomarkers that can predict outcome of radiation based therapy.

METHODS

We initially evaluated RNA expression using cDNA microarray analysis of 38 patients that received radiotherapy (RT). The five strongest candidates (VEGF, BCL-2, CLAUDIN-4, YAP-1 and c-MET) were then analysed in pre-treatment biopsies in a second group of 86 patients who received radiation based treatment using immunohistochemical staining (IHC), prepared by tissue microarray.

RESULTS

In the first population, 13 of 38 (34%) had no (NR) or partial response (PR) to RT. cDNA microarrays revealed 60 genes that were linked to response to therapy. In the second series, 12 of 86 patients (14%) experienced NR or PR to CRT. Cause specific survival (CSS) and recurrence free survival (RFS) at 2 years was 85% and 90% and at 3 years 81% and 84%, respectively. Biomarkers predictive for NR/PR were increased expression of vascular endothelial growth factor (VEGF) (p=0.02), Yes-associated protein (YAP-1) (p<0.01), CLAUDIN-4 (p<0.01), c-MET (p<0.01) and BCL-2 (p=0.02). Biomarkers predictive of poor RFS were YAP-1 (p=0.01) and BCL-2 (p<0.01). Biomarkers predictive of poor CSS were YAP-1 (p=0.04), VEGF (p=0.03) and CLAUDIN-4 (p=0.03). Furthermore, when YAP-1 and c-MET expression levels were combined the prediction of radio-resistance was increased.

CONCLUSION

All five biomarkers were predictive of poor response to radiation based therapy. In particular, YAP-1 and c-MET have synergistic power and could be used to make treatment decisions.

Effect of silencing Bcl-2 expression by small interfering RNA on radiosensitivity of gastric cancer BGC823 cells

OBJECTIVE

To explore the influence of silencing Bcl-2 expression by small interfering RNA (siRNA) on Bcl-2 protein expression, cell apoptosis rate and radiosensitivity of gastric cancer BGC823 cells.

METHODS

siRNA segment for Bcl-2 gene was designed and synthesized, then was induced into gastric cancer BGC 823 cells by liposome transfection. Bcl-2 protein expression was detected by Western Blotting. After X radiation, flow cytometry and clone forming assay were used to determine the effects of RNA interference on BGC823 cell apoptosis rate and radiosensitivity.

RESULT

After the transfection of Bcl-2 siRNA, the positive expression rate of Bcl-2 protein in BGC823 cells was (35.45±2.35)%. Compared with the control group and negative siRNA transfection group, the rate was significantly decreased (P<0.01). The apoptosis rate of BGC823-RNAi cell was (10.81±0.91)%, which was significantly higher than the control group and negative siRNA transfection group (P<0.01). After 48h X radiation, the apoptosis rate of BGC823-RNAi was (28.91±1.40)%, which was significantly higher than the control group and the group without radiation (P<0.01). During clone forming assay D(0), D(q) and SF(2) values in Bcl-2 siRNA1 transfection group were all lower than those in the control group. The radiosensitivity ratio was 1.28 (the ratio of D(0)) and 1.60 (the ratio of D(q)).

CONCLUSIONS

Specific siRNA of Bcl-2 gene can effectively inhibit the expression of Bcl-2 gene, enhance the radiosensitivity and apoptosis of gastric cancer BGC823 cells, having good clinical application perspective.

RRM2 regulates Bcl-2 in head and neck and lung cancers: a potential target for cancer therapy

PURPOSE

Ribonucleotide reductase subunit M2 (RRM2) plays an active role in tumor progression. Recently, we reported that depletion of RRM2 by systemic delivery of a nanoparticle carrying RRM2-specific siRNA suppresses head and neck tumor growth. The aim of this study is to clarify the underlying mechanism by which RRM2 depletion inhibits tumor growth.

EXPERIMENTAL DESIGN

siRNA-mediated gene silencing was carried out to downregulate RRM2. Immunoblotting, reverse-transcriptase PCR, confocal microscopy, tissue fractionation, gene overexpression and knockdown were employed to analyze critical apoptosis signaling. Conventional immunohistochemistry and quantum dot-based immunofluorescence were applied to detect RRM2 and Bcl2 expression and localization in tissue samples from patients and mice.

RESULTS

Knockdown of RRM2 led to apoptosis through the intrinsic pathway in head and neck squamous cell carcinoma (HNSCC) and non-small cell lung cancer (NSCLC) cell lines. We showed that Bcl-2 is a key determinant controlling apoptosis, both in vitro and in vivo, and that RRM2 depletion significantly reduces Bcl-2 protein expression. We observed that RRM2 regulates Bcl-2 protein stability, with RRM2 suppression leading to increased Bcl-2 degradation, and identified their colocalization in HNSCC and NSCLC cells. In a total of 50 specimens each from patients with HNSCC and NSCLC, we identified the colocalization of Bcl-2 and RRM2 and found a significant positive correlation between their expression in HNSCC (R = 0.98; P < 0.0001) and NSCLC (R = 0.92; P < 0.0001) tumor tissues.

CONCLUSIONS

Our novel findings add to the knowledge of RRM2 in regulating expression of the antiapoptotic protein Bcl-2 and reveal a critical link between RRM2 and Bcl-2 in apoptosis signaling.

Deubiquitinase USP9x confers radioresistance through stabilization of Mcl-1

Myeloid cell leukemia sequence 1 (Mcl-1), an antiapoptotic member of the Bcl-2 family, is often overexpressed in tumor cells limiting the therapeutic success. Mcl-1 differs from other Bcl-2 members by its high turnover rate. Its expression level is tightly regulated by ubiquitylating and deubiquitylating enzymes. Interaction of Mcl-1 with certain Bcl-2 homology domain 3 (BH3)-only members of the Bcl-2 family can limit the access to Mcl-1 ubiquitin ligase E3 and stabilizes the antiapoptotic protein. In addition, the overexpression of the deubiquitinase ubiquitin-specific protease 9x (USP9x) can result in the accumulation of Mcl-1 by removing poly-ubiquitin chains from Mcl-1 preventing its proteasomal degradation. Analyzing radiation-induced apoptosis in Jurkat cells, we found that Mcl-1 was downregulated more efficiently in sensitive parental cells than in a resistant subclone. The decline of Mcl-1 correlated with cell death induction and clonogenic survival. Knockdown of BH3-only proteins Bim, Puma, and Noxa did not affect Mcl-1 level or radiation-induced apoptosis. However, ionizing radiation resulted in activation of USP9x and enhanced deubiquitination of Mcl-1 in the radioresistant cells preventing fast Mcl-1 degradation. USP9x knockdown enhanced radiation-induced decrease of Mcl-1 and sensitized the radioresistant cells to apoptosis induction, whereas USP9x knockdown alone did not change Mcl-1 level in unirradiated cells. Together, our results indicate that radiation-induced activation of USP9x inhibits Mcl-1 degradation and apoptosis resulting in increased radioresistance.

Treatment results and prognostic factors of patients undergoing postoperative radiotherapy for laryngeal squamous cell carcinoma

Postoperative radiotherapy (PRT) is widely advocated for patients with squamous cell carcinomas of the head and neck that are considered to be at high risk of recurrence after surgical resection. The aims of this study were to evaluate the treatment outcomes of PRT for patients with laryngeal carcinoma and to identify the value of several prognostic factors. We reviewed the records of 256 patients treated for laryngeal squamous cell carcinoma between January 1993 and December 2005. Disease-free survival (DFS) and overall survival (OS) were estimated using the Kaplan-Meier method. Log-rank test was employed to identify significant prognostic factors for DFS and OS. The Cox proportional hazards model was applied to identify covariates significantly associated with the aforementioned endpoints. Our results showed the 3-, 5-, and 10-year DFS for all patients were 69.9%, 59.5%, and 34.9%, respectively. The 3-, 5-, and 10-year OS rates were 80.8%, 68.6%, and 38.8%, respectively. Significant prognostic factors for both DFS and OS on univariate analysis were grade, primary site, T stage, N stage, overall stage, lymph node metastasis, overall treatment times of radiation, the interval between surgery and radiotherapy, and radiotherapy equipment. Favorable prognostic factors for both DFS and OS on multivariate analysis were lower overall stage, no cervical lymph node metastasis, and using 60Co as radiotherapy equipment. In conclusion, our data suggest that lower overall stage, no cervical lymph node metastasis, and using 60Co as radiotherapy equipment are favorable prognostic factors for DFS and OS and that reducing the overall treatment times of radiation to 6 weeks or less and the interval between surgery and radiotherapy to less than 3 weeks are simple measures to remarkably improve treatment outcome.

Linifanib (ABT-869) enhances radiosensitivity of head and neck squamous cell carcinoma cells

OBJECTIVES

Novel targeted therapeutic strategies to overcome radio-resistance of cancer cells traditionally treated with radiation may improve patient survival with the added benefit of reduced systemic toxicity. Herein, we tested the feasibility of Linifanib (ABT-869), a multi-receptor tyrosine kinase inhibitor of members of vascular endothelial growth factor (VEGF) and platelet derived growth factor (PDGF) receptor families, on radio-sensitization of Head and Neck Squamous Cell Carcinoma (HNSCC).

MATERIALS AND METHODS

UMSCC-22A and UMSCC-22B cells were treated with Linifanib and γ-radiation response was determined. Cell viability, cytotoxicity, apoptosis induction and cell cycle distribution were examined by MTT assay, colony formation assay and flow cytometry. In addition, expression of STAT3 and downstream signaling proteins were assessed using western immunoblotting.

RESULTS

Treatment with Linifanib resulted in cell growth inhibition, G2/M cell cycle arrest, induction of cell death via apoptosis, reduced phosphorylation of STAT3, which has been linked to radio-resistance, lower expression of cyclin D1, survivin and increased PARP cleavage. In addition, Linifanib overcame the radio-resistance of the cell lines and significantly enhanced radiation-induced cytotoxicity (p<0.05).

CONCLUSION

These data suggest the possibility of combining targeted therapeutic such as Linifanib with radiation to enhance inhibition of cell growth and apoptosis in HNSCC cells. Thus, it may provide a novel therapeutic strategy and improve efficacy of radiation against HNSCC in the future.

hPEBP4 as a predictive marker for the pathological response of rectal cancer to preoperative radiotherapy

PURPOSE

The ability to predict tumor sensitivity toward radiotherapy is important in the personalized application of preoperative radiotherapy for patients with rectal cancer. The aim of the present study was to test the human phosphatidylethanolamine-binding protein 4 (hPEBP4) as a predictive marker of tumor response to preoperative radiotherapy in patients with rectal cancer.

METHOD

A retrospective analysis was conducted, consisting of 86 patients with locally advanced rectal cancer who underwent short-course preoperative radiotherapy (20 Gy in five fractions for 1 week) followed by a radical resection. Both pretreatment biopsy specimens and resected primary tumor tissue were collected. Immunohistochemistry and tumor regression grading system were used to evaluate the expression of hPEBP4 in the pretreatment biopsy specimens and the response of rectal cancer to radiotherapy, respectively. Expression of hPEBP4 was correlated with tumor regression in the resected specimen and the clinical outcome of the patients as well.

RESULTS

We found that high expression of hPEBP4 was associated with radioresistance in both univariate and multivariate analyses, and patients with a high hPEBP4 expression had a poorer progression-free survival than those with low hPEBP4 expression.

CONCLUSION

Our study revealed the independent predictive values of hPEBP4 in response of rectal cancer to preoperative radiotherapy, which suggests that upregulating hPEBP4 might be a potential mechanism by which rectal cancer cells avoid the destructive effects of radiotherapy.

Study of the UTMD-based delivery system to induce cervical cancer cell apoptosis and inhibit proliferation with shRNA targeting Survivin

Apoptosis induction by short hairpin RNA (shRNA) expression vectors could be an efficient and promising strategy for cancer gene therapy. Ultrasound-targeted microbubble destruction (UTMD) is an appealing technique. In this study, we investigated the apoptosis induction and suppression of cell proliferation in vivo transfected by the UTMD-based shRNA delivery system. Nude mice with transplanted tumors of cervical cancer were randomly arranged into three groups: control group, plasmid injection and ultrasound (P + US), P + UTMD group. Expressions of Survivin and proliferating cell nuclear antigen (PCNA), Bcl-2, Bax, Caspase-3, Ki-67, nucleostemin (NS) were investigated by immunohistochemistry. Furthermore, microvessel density (MVD) was detected by CD34 protein expressions and apoptotic index (AI) was measured by TUNEL. As compared with those in the control and P + US groups, protein expressions of PCNA, Ki-67, Bcl-2, Survivin and NS in P + UTMD groups were down-regulated markedly, while those of Bax, Caspase-3 were up-regulated significantly (p < 0.05). MVD decreased significantly, whereas AI increased remarkably (p < 0.05). We suggested that UTMD-based shRNA delivery system could induce apoptosis and inhibit proliferation significantly, without causing any apparently adverse effect, representing a new, promising technology that would be used in the future gene therapy and research.