Novel molecular targeted therapy for esophageal cancer

An In Vivo Study of Lactobacillus rhamnosus (PTCC 1637) as a New Therapeutic Candidate in Esophageal Cancer

Objective

This study is aimed at investigating the effect of probiotic Lactobacillus rhamnosus on esophageal cancer in vivo and in vitro.

Methods and Results

In this study, the cytotoxicity effects of L. rhamnosus supernatant and whole-cell culture on a cancer cell line (Kyse30) compared to 5fu were evaluated by the MTT assay. The real-time PCR method was used to analyse the L. rhamnosus supernatant effect on the expression of Wnt signaling pathway genes. An in vivo investigation in nude mice was done to assess the anti-tumor activity of L. rhamnosus supernatant and whole-cell culture. Both supernatant and whole-cell culture of L. rhamnosus reduced cell survival (Kyse30) P < 0.001. The supernatant of this bacterium significantly reduced the expression of Wnt signaling pathway genes. Administration of supernatant and whole-cell culture of L. rhamnosus expressively reduced tumor growth compared to the control group. The effects of this bacterium on tumor necrosis were quite evident, pathologically P < 0.01.

Conclusion

This study is the first report that assessed the potential impact of L. rhamnosus, especially its supernatant on esophageal cancer and Wnt signaling pathway genes. Therefore, this bacterium can be a harmless candidate for esophageal cancer therapy.

Hypoxia-induced RBBP7 promotes esophagus cancer progression by inducing CDK4 expression

Hypoxia-induced epigenetic regulation calls for more effective therapeutic targets for esophageal cancer. We used GEPIA and UALCAN databases to screen survival-related and cancer stage-associated genes. Eca109 and KYSE450 esophageal cancer cell lines were cultured under normoxia, hypoxia, or CoCl-induced hypoxia conditions, which were further transfected with plasmids expressing RB binding protein 7 (RBBP7), hypoxia-inducible factor 1 (HIF1)-α, or RBBP7 shRNA. Colony formation and MTT assays were used to detect cell proliferation. Tumor sphere formation and stemness marker detection were applied to assess cell stemness. RT-PCR and western blot analysis were used to detect the relative mRNA level and protein expression, respectively. Luciferase assay was utilized to detect the direct interaction between HIF1α and RBBP7. Up-regulated RBBP7 was identified as one of the most prominent survival-related genes, which is negatively correlated with the overall survival (OS), disease recurrence-free survival (DFS), and tumor stages. Hypoxia-induced HIF1α up-regulates RBBP7 expression, which promotes esophagus cancer cell viability, proliferation, and stemness with increased cyclin-dependent kinase 4 (CDK4) expression. Luciferase reporter assay verified that HIF1α transcriptionally regulates the expression of RBBP7. We conclude that hypoxia induces high expression of RBBP7 which is at least partially mediated by HIF1α, up-regulates the expression of downstream CDK4, and thereby promotes tumor progression in esophageal cancer cells.

PRMT5 promotes progression of endometrioid adenocarcinoma via ERα and cell cycle signaling pathways

Protein arginine methyltransferase 5 (PRMT5) has previously been reported to be upregulated in many malignant tumors. This study investigated the significance of PRMT5 in endometrial carcinoma (EC) and explored its function in tumorigenesis. Immunohistochemistry was performed to evaluate PRMT5 expression in 62 EC and 66 endometrial hyperplasia samples. The functions of PRMT5 were investigated by cell counting kit‐8, plate colony formation, wound healing, and transwell and flow cytometry assays. Quantitative reverse transcription‐polymerase chain reaction and western blotting were used to measure the expression of PRMT5, changes in estrogen receptor α (ERα), and related functional proteins. Coimmunoprecipitation was performed to examine the interaction of PRMT5 with ERα and its coactivator steroid receptor coactivator‐1 (SRC1). Compared to endometrial hyperplasia tissue, PRMT5 was overexpressed in endometrioid adenocarcinoma (EAC) but not overexpressed in mucinous EC. The main expression pattern of PRMT5 in EAC was cytoplasmic. However, the positive cases of endometrial hyperplasia showed both cytoplasmic and nuclear positivity in the endometrial glands or were mainly positive in stromal cells. Knockdown of PRMT5 significantly inhibited the growth and migration ability of EAC cells and promoted their apoptosis by regulating cyclin D1, c‐myc, p53, and Bcl2 proteins. Furthermore, PRMT5 could form a complex with ERα and SRC1 to promote the expression of ERα. In conclusion, PRMT5 plays a significant role in the progression of EAC by interacting with ERα and impacting the cell cycle signaling pathways.

Plantamajoside inhibits lipopolysaccharide-induced epithelial-mesenchymal transition through suppressing the NF-κB/IL-6 signaling in esophageal squamous cell carcinoma cells

Plantamajoside (PMS) is a major compound of Plantago asiatica and possesses anti-tumor activity. However, the effect of PMS on esophageal squamous cell carcinoma (ESCC) and the underlying mechanism of action are unclear. The present study aimed to evaluate the effect of PMS on lipopolysaccharide (LPS)-induced epithelial-mesenchymal transition (EMT) in ESCC. The results showed that PMS inhibited viability of ESCC cell lines (Eca-109 and TE-1) in a concentration-dependent manner. PMS also inhibited LPS-induced EMT in ESCC cells. PMS inhibited LPS-induced activation of the NF-κB pathway and IL-6 expression. PMS also suppressed IL-6-induced EMT in ESCC cells. Treatment of BAY11-7082 (an inhibitor of NF-κB) or antibody against IL-6 alleviated the effect of LPS-induced EMT in ESCC cells. Besides, inhibition of NF-κB decreased IL-6 expression. In conclusion, the results indicated that PMS inhibited LPS-induced EMT through suppressing the NF-κB/IL-6 signaling in ESCC cell lines, suggesting that PMS might be a useful agent for the treatment of ESCC.

Esophageal Cancer: Associated Factors with Special Reference to the Kashmir Valley

Esophageal cancer is one of the most common cancers worldwide. It is a multifactorial disease, and no single agent has been identified so far as the sole cause of the cancer. Many factors like smoking, the consumption of alcohol, fungal-contaminated, spicy and various nitrosamine-containing food stuffs and hot beverages, nutritional deficiency of some vitamins like β-carotene, vitamin A, C and E and minerals like zinc, selenium and molybdenum, the use of opium, HPV infection and various genetic factors have been found associated with the occurrence of the disease worldwide. Wide geographic differences and substantial changes in the incidence of esophageal cancer occurring over time have been suggested. Among the risk factors in India, betel quid chewing carries a relatively high risk. High incidences in Kashmir have been associated with the consumption of hot salted tea, sun-dried, smoked foods, tobacco in the form of hukka and various genetic factors. The exact cause of esophageal squamous cell carcinoma is unknown. Much work has been carried out on the role of various environmental factors, gene mutations, and polymorphisms worldwide, including Kashmir. Although the Kashmir valley is present on the border of the ‘high risk esophageal cancer belt’ and esophageal squamous cell carcinoma represents the most commonly occurring malignancy in Kashmir, the amount of information available on various associated factors is still very little as there is a paucity of various epidemiological and molecular studies being carried out in this field.

Ectopic expression of TWIST1 upregulates the stemness marker OCT4 in the esophageal squamous cell carcinoma cell line KYSE30

Background

The transcription factor TWIST1 plays an important role in the epithelial–mesenchymal transition (EMT) process and in the migration, invasion and metastasis of cancer cells. OCT4, which is a homeobox transcription factor, has an important role in the self-renewal potential of cancer cells. Our aim here is to elucidate impact of ectopic expression of TWIST1 on OCT4 gene expression in esophageal squamous cell carcinoma (ESCC).

Methods

The ESCC line was KYSE30. GP293T cells were transfected with purf-IRES-GFP and pGP plasmids to produce recombinant viral particles. A semi-confluent KYSE30 culture was transduced with the prepared retroviral particles. mRNA extraction and cDNA synthesis were performed from normal KYSE30 cells and those ectopically expressing TWIST1. Expressional analysis of TWIST1 and OCT4 were performed with relative comparative real-time PCR.

Results

Ectopic expression of TWIST1 in KYSE30 cells was related to its significant overexpression: nearly nine-fold higher in GFP-hTWIST1 KYSE-30 cells than in control GFP cells. This induced expression of TWIST1 caused significant upregulation of OCT4 in GFP-hTWIST1 KYSE-30 cells: nearly eight-fold higher. In silico analysis predicted the correlation of TWIST1 and OCT4 through ETS2.

Conclusions

Overexpressed TWIST1 can be correlated with upregulation of the cancer stem cell marker OCT4 and the protein may play critical regulatory role in OCT4 gene expression. Since OCT4 is involved in the self-renewal process, the results may suggest a new linkage between TWIST1 and OCT4 in the cell biology of ESCC, highlighting the probable role of TWIST1 in inducing self-renewal.

Inhibition of human esophageal squamous cell carcinomas by targeted silencing of tumor enhancer genes: an overview

Esophageal cancer has been reported as the ninth most common malignancy and ranks as the sixth most frequent cause of death worldwide. Esophageal cancer treatment involves surgery, chemotherapy, radiation therapy, or combination therapy. Novel strategies are needed to boost the oncologic outcome. Recent advances in the molecular biology of esophageal cancer have documented the role of genetic alterations in tumorigenesis. Oncogenes serve a pivotal function in tumorigenesis. Targeted therapies are directed at the unique molecular signature of cancer cells for enhanced efficacy with low toxicity. RNA interference (RNAi) technology is a powerful tool for silencing endogenous or exogenous genes in mammalian cells. Related results have shown that targeting oncogenes with siRNAs, specifically the mRNA, effectively reduces tumor cell proliferation and induces apoptotic cell death. This article will briefly review studies on silencing tumor enhancer genes related to the induction of esophageal cancer.

Cetuximab plus cisplatin, irinotecan, and thoracic radiotherapy as definitive treatment for locally advanced, unresectable esophageal cancer: a phase-II study of the SWOG (S0414)

INTRODUCTION

The specific aims of the study were to evaluate the 2-year overall survival (OS) and progression-free survival (PFS), toxicity profile, and best objective response rate in patients with locally advanced, clinically unresectable esophageal cancer receiving cetuximab, cisplatin, irinotecan, and thoracic radiotherapy (TRT) within a multi-institutional cooperative-group setting.

METHODS

Eligible patients (cT4 M0 or medically unresectable, biopsy proven, and noncervical esophageal cancer) were to receive four 21-day cycles of cetuximab 400 mg/m (day 1, cycle 1), cetuximab 250 mg/m (day 8, 15, cycle 1; then days 1, 8, and 15 for subsequent cycles), cisplatin 30 mg/m (days 1 and 8, all cycles), and irinotecan 65 mg/m (days 1 and 8, all cycles). TRT was administered at 1.8 Gy in 28 daily fractions to a total dose of 50.4 Gy, to begin with on day 1 of cycle 3. The primary endpoint was 2-year OS, with an accrual goal of 75 patients with adenocarcinoma.

RESULTS

The study was closed because of slow accrual, with 21 eligible patients (11 squamous, 10 adenocarcinoma) enrolled from May 2005 to September 2007. Two-year OS and PFS (95% confidence interval [CI]) were 33.3% (14.6-57.0%) and 23.8% (8.2-47.2%), respectively. Kaplan-Meier estimates of median (95% CI) OS and PFS were 11.2 (6.4-43.6) and 6.4 (3.7-12.0) months, respectively. The overall response rate (95% CI) among 17 evaluable patients was 17.6% (3.8-43.4%), including 6% confirmed complete responders and 12% unconfirmed partial responders. Two deaths resulted from protocol treatment (sudden death and gastrointestinal necrosis). Ten (47.6%) and 6 (28.6%) patients had grade-3 or -4 toxicity, respectively: 52.4% were hematologic, 23.8% had fatigue, 19.0% had nausea, 19.0% had dehydration, and 19.0% had anorexia.

CONCLUSIONS

Concomitant cetuximab, cisplatin, irinotecan, and TRT were poorly tolerated in the first North American cooperative group trial testing this regimen for locally advanced esophageal cancer as treatment-related mortality approached 10%. Single-institution phase-II cetuximab-based combined modality trials have yielded encouraging results in preliminary analyses. The SWOG GI Committee endorses enrollment to open clinical trials to clarify the therapeutic ratio of cetuximab-based combined modality approaches for esophageal cancer.

Decreased expression of CIAPIN1 is correlated with poor prognosis in patients with esophageal squamous cell carcinoma

BACKGROUND

CIAPIN1, a newly identified antiapoptotic molecule, is a downstream effector of the receptor tyrosine kinase-Ras signaling pathway in the mouse Ba/F3 pro-B cell line. Neither CIAPIN1 expression nor its clinical significance has been previously examined in esophageal squamous cell carcinoma (ESCC), and the present immunohistochemical analysis is the first study on CIAPIN1 distribution in ESCC.

AIMS

To investigate the relationships between the expression of CIAPIN1 and clinicopathological characteristics of ESCC, and evaluate the relationship between the expression of this gene and prognosis in ESCC patients.

METHODS

The expression of CIAPIN1 was investigated in 112 surgically resected specimens of ESCC by immunohistochemistry using a specific monoclonal antibody. The relations of CIAPIN1 expression with clinicopathological characteristics and the postoperative survival rate were statistically analyzed.

RESULTS

We found that the expression of CIAPIN1 was statistically correlated with the degree of differentiation, depth of invasion, and lymph node metastasis of ESCC. Consistently, the survival rates of patients with CIAPIN1-negative tumors tended to be statistically lower than those with CIAPIN1-positive tumors. However, no significant difference was observed between CIAPIN1 expression and the patient age, sex, tumor location, and distant metastasis. Furthermore, multivariate analysis was performed by using Cox's proportional hazards model, and the results showed that lymph node metastases and CIAPIN1 expression were two independent prognostic factors.

CONCLUSIONS

CIAPIN1 might play an important role in esophageal carcinogenesis, and it could be considered as a valuable prognostic indicator in ESCC. Finally, functional enhancement of CIAPIN1 might lead to a novel strategy for the treatment of SCC in the esophagus.

Pharmacokinetics and pharmacogenomics in esophageal cancer chemoradiotherapy

Esophageal cancer is one of the most lethal malignancies. Surgical resection of the tumor from the primary site has been the standard treatment, especially for localized squamous cell carcinoma, but considerable clinical efforts during the last decade have resulted in novel courses of treatment. These options include chemoradiotherapy, consisting of a continuous infusion of 5-fluorouracil (5-FU), cisplatin (CDDP), and concurrent radiation. Given the substantial inter- and/or intra-individual variation in clinical outcome, future improvements will likely require the incorporation of a novel anticancer drug, pharmacokinetically guided administration of CDDP or 5-FU, and identification of potential responders by patient genetic profiling prior to treatment. In this review, the latest information on incidence, risk factors, biomarkers, therapeutic strategies, and the pharmacokinetically guided or genotype-guided administration of CDDP and 5-FU is summarized for future individualization of esophageal cancer treatment.

Targets for molecular therapy in esophageal squamous cell carcinoma: an immunohistochemical analysis

Neoadjuvant chemotherapy may improve the outcome of esophageal cancer after esophagectomy, but is accompanied by considerable toxicity by collateral destruction of normal cells. Such side effects may be avoided by developing therapies that specifically target molecular characteristics of tumors. The aim of the present study was to determine the proportion of esophageal squamous cell carcinoma (ESCC) patients that could possibly benefit from (a combination of) currently available targeted therapies, by assessing the frequency of immunohistochemical expression of their target molecular markers in ESCC tissues. Sections from a validated tissue microarray comprising 108 ESCCs were immunohistochemically stained for Bcl-2, c-KIT, cyclo-oxygenase-2 (COX-2), cyclin D1, estrogen receptor (ER), epidermal growth factor receptor (EGFR), Her-2/neu, progesterone receptor (PR), and vascular endothelial growth factor (VEGF). VEGF, cyclin D1, EGFR, and COX-2 could be detected in 55, 42, 40, and 40%, respectively. Her-2/neu, Bcl-2, and c-KIT were detected in 12, 11, and 10% of the tumors, respectively. No nuclear expression of ER or PR was noticed. Concurrent expression of two markers was noticed in 28% of ESCCs, whereas 25% of ESCCs showed concurrent expression of three markers. The concurrent expression of two of the most frequently expressed markers (VEGF, cyclin D1, EGFR, and COX-2) ranged from 11 (COX-2 and EGFR) to 26% (cyclin D1 and VEGF). The expression of all of these four markers was seen in 5% of ESCCs. Promising targets for molecular therapy in ESCC appear to be COX-2, VEGF, EGFR, and cyclin D1, as they are frequently overexpressed. Phase II clinical studies on these molecular markers may therefore be warranted. The role for targeted therapy against ER, PR, Her-2/neu, c-KIT, or Bcl-2 in ESCC seems limited.

Novel thermo-sensitive core-shell nanoparticles for targeted paclitaxel delivery

Novel thermo-sensitive nanoparticles self-assembled from poly(N,N-diethylacrylamide-co-acrylamide)-block-poly(gamma-benzyl L-glutamate) were designed for targeted drug delivery in localized hyperthermia. The lower critical solution temperature (LCST) of nanoparticles was adjusted to a level between physiological body temperature (37 degrees C) and that used in local hyperthermia (about 43 degrees C). The temperature-dependent performances of the core-shell nanoparticles were systemically studied by nuclear magnetic resonance (NMR), circular dichroism (CD), fluorescence spectroscopy, dynamic light scattering (DLS), and atom force microscopy (AFM). The mean diameter of the nanoparticles increased slightly from 110 to 129 nm when paclitaxel (PTX), a poorly water-soluble anti-tumor drug, was encapsulated. A stability study in bovine serum albumin (BSA) solution indicated that the PTX loaded nanoparticles may have a long circulation time under physiological environments as the LCST was above physiological body temperature and the shell remained hydrophilic at 37 degrees C. The PTX release profiles showed thermo-sensitive controlled behavior. The proliferation inhibiting activity of PTX loaded nanoparticles was evaluated against Hela cells in vitro, compared with Taxol (a formulation of paclitaxel dissolved in Cremophor EL and ethanol). The cytotoxicity of PTX loaded nanoparticles increased obviously when hyperthermia was performed. The nanoparticles synthesized here could be an ideal candidate for thermal triggered anti-tumor PTX delivery system.

Novel thermosensitive polymeric micelles for docetaxel delivery

Targeted delivery of antitumor drugs triggered by hyperthermia has significant advantages in clinical applications, since it is easy to implement and side effects are reduced. To release drugs site-specifically upon local heating often requires the drugs to be loaded into a thermosensitive polymer matrix with a low critical solution temperature (LCST) between 37 and 42 degrees C. However, the LCSTs of most thermosensitive materials were below 37 degrees C, which limits their application in clinic because they would precipitate once injected into human body and lost thermal targeting function. Herein, we prepared a novel thermosensitive copolymer (poly(N-isopropylacrylamide-co-acrylamide)-b-poly (DL-lactide)) that exhibits no obvious physical change up to 41 degrees C when heated. Docetaxel loaded micelles made of such thermosensitive polymer were prepared by dialysis method and the maximum loading content was found to be up to 27%. The physical properties, such as structure, morphology, and size distribution of the micelles with and without docetaxel were investigated by NMR, X-ray diffraction, dynamic light scattering, atomic force microscopy, etc. The efficacy of this drug delivery system was also evaluated by examining the proliferation inhibiting activity against different cell lines in vitro. After hyperthermia, the cytotoxicity of docetaxel-loaded micelles increased prominently. Our results demonstrated that this copolymer could be an ideal candidate for thermal targeted antitumor drug delivery.

Expression and prognostic value of MG7-Ag in patients with surgically resectable esophageal squamous cell carcinoma

PURPOSE

MG7-Ag is a human gastric-carcinoma-associated antigen. The expression of MG7-Ag was found to increase gradually with the development and progression of gastric cancer. Moreover, a poorer prognosis was found in MG7-Ag positive gastric-carcinoma patients than in MG7-Ag negative patients. However, neither MG7-Ag expression nor its clinical significance has been previously examined in squamous cell carcinoma (SCC) of the esophagus. In this study, we examined the expression of MG7-Ag in esophageal squamous cell carcinomas to assess its value as a prognostic indicator.

METHODS

The expression of MG7-Ag was detected in 112 cases of esophageal squamous cell carcinoma (SCC) by immunohistochemical analysis. The relation of MG7-Ag staining with various clinicopathological features was statistically analyzed.

RESULTS

The staining of MG7-Ag was detected in SCC, while not in normal epithelial cells. In esophageal SCC, MG7-Ag was found significantly correlated with depth of invasion (P = .012), in T4, T3 carcinomas but not in T2, T1 carcinomas, lymph node metastases (P = .029), pathological stage (P = .005). Consistently, the survival rate tended to be statistically lower in patients with MG7-Ag positive SCCs than in MG7-Ag negative SCCs (P = .005). However, no significant difference was observed between MG7-expression and patient age, sex, tumor location, differentiation, distant metastasis, and lymphatic invasion.

CONCLUSION

MG7-Ag might play a positive role in the process of carcinogenesis and progression of esophageal SCC, and it could be considered as one valuable prognostic indicator in esophageal SCC.

The role of the mitochondria in mediating cytotoxicity of anti-cancer therapies

Optimal cytotoxic anticancer therapy, at the cellular level, requires effective and selective induction of cell death to achieve a net reduction of biomass of malignant tissues. Standard cytotoxic chemotherapeutics have been developed based on the observations that mitotically active cancer cells are more susceptible than quiescent normal cells to chromosomal, microtubular or metabolic poisons. More recent development of molecularly targeted drugs for cancer focuses on exploiting biological differentials between normal and transformed cells for selective eradication of cancers. The common thread of "standard" and "novel" cytotoxic drugs is their ability to activate the apoptosis-inducing machinery mediated by mitochondria, also known as the intrinsic death signaling cascade. The aim of this article is to provide an overview of the role of the mitochondria, an energy-generating organelle essential for life, in mediating death when properly activated by cytotoxic stresses.

Her-2/neu in barrett esophagus: a comparative study between histology, immunohistochemistry, and fluorescence in situ hybridization

Her-2/neu is a protooncogene frequently overexpressed in breast cancer, recently found to be also overexpressed in carcinoma arising on Barrett esophagus (BE). Immunohistochemistry and fluorescence in situ hybridization (FISH) are conventionally used for Her-2 testing in carcinomas, but a single assay is not yet accepted as a "gold standard" in BE. To evaluate the correlation between histopathology variables and gene expression/amplification in the sequence BE-low grade dysplasia-high grade dysplasia-adenocarcinoma, fifty esophageal specimens from patients with a diagnosis of BE (21 BE, 4 low-grade dysplasia, 12 high-grade dysplasia, and 13 adenocarcinomas) were evaluated. Histopathologic evaluation was carried out using hematoxylin and eosin staining. Paraffin-embedded tissues were investigated for Her-2 by immunohistochemistry (HercepTest) and FISH. HercepTest was scored 0, 1+, 2+, and 3+ depending on the percentage (cut off 10%) of membrane staining, whereas gene assessment evaluated by FISH was based on the ratio between Her-2/neu and the 17 chromosome copy number. There was a positive correlation between gene amplification and protein overexpression. No case with HercepTest scoring 0 or 1+ displayed gene amplification, but this was present in 20% of cases scoring 2+ and in all cases scoring 3+. Her-2/neu amplification or overexpression was never observed in BE. Gene amplification and overexpression was observed in more than 50% of dysplasias and adenocarcinomas. Her-2/neu amplification/overexpression might be considered as a marker of progression from BE to dysplasia. FISH may represent a useful diagnostic tool to integrate the result of HercepTest for selecting patients for more targeted therapeutic approaches.