Differential expression of Bcl-2, Bcl-XL and p53 in colorectal cancer

Astilbin targeted Sirt1 to inhibit acetylation of Nrf2 to alleviate grass carp hepatocyte apoptosis caused by PCB126-induced mitochondrial kinetic and metabolism dysfunctions

3, 3', 4, 4', 5-pentachlorobiphenyl (PCB126) is extensively utilized in electronic products, lubricant, and insecticide due to its excellent chemical stability and insulation prosperity, resulting in its frequent detection in environment. In addition, atmospheric deposition, as well as industrial and urban wastewater discharge can also lead to PCB126 contamination in marine environment, triggering damages to the tissues of aquatic organisms through oxidative stress. Astilbin is a type of flavonoid compound found in plants that plays a crucial role in providing powerful antioxidant and anti-inflammatory properties. In this study, we aimed to investigate the specific mechanism of PCB126-induced damage and the potential protective effect of Astilbin. To achieve this, we treated grass carp hepatocytes (L8824) with 75 μM PCB126 and/or 0.5 mM Astilbin for 24 h and used experimental methods such as Flow cytometry, molecular docking, PPI analysis, detection of commercial kits (ATP concentration and ATPnase activity) and measurement of mitochondrial membrane potential (ΔΨm). Our findings revealed that PCB126 exposure resulted in a decrease in expression levels of Sirt1, factors related to mitochondrial fusion (Opa1, Mfn1, and Mfn2), antioxidant (CAT, SOD1, and SOD2), energy metabolism (PKM2, IDH, and SDH) and anti-apoptosis (Bcl-2), and an increase in expression levels of Nrf2 acetylation, mitochondrial fission (Drp1), factors that promote apoptosis (Cytc, Bax, Cas9, and Cas3) in L8824 cells. Furthermore, our findings revealed a decrease in ΔΨm, ATP concentration and ATPnase activity and apoptosis levels in L8824 cells. Noteworthy, treatment with Astilbin reversed these results. Molecular docking provides solid evidence for the interaction between Astilbin and Sirt1. In summary, our findings suggested that Astilbin promoted the deacetylation of Nrf2 by interacting with Sirt1, thereby alleviating PCB126-induced mitochondrial apoptosis mediated by mitochondrial dynamics imbalance and energy metabolism disorder through the inhibition of oxidative stress in L8824 cells. Our research has initially revealed the correlation between acetylation and apoptosis induced by PCB126, which provided a foundation for a better comprehension of PCB126 toxicity. Additionally, it expanded the potential application value of Astilbin.

The complementary role of lymphovascular invasion and perineural invasion in the TNM staging process of rectal cancer

The aim of this study is to clarify the association between lymphovascular invasion (LVI) and/or perineural invasion (PNI) and the clinical characteristics and prognostic importance of rectal cancer, to provide a basis for early adjuvant treatment of rectal cancer. We retrospectively analyzed patients diagnosed with rectal cancer. This study involved rectal cancer tissue samples were obtained by surgical methods. Data on histological form, tumor classification, tumor size, gross growth pattern, blood and lymphatic vessel invasion, and PNI of the slice by HE staining were obtained from pathological examination. Immunohistochemical analysis of tissue samples was performed to determine p53 and EGFR expressions. There were 330 rectal cancer patients included in the study. LVI and/or PNI can be used as a high-risk factor for the prognosis of rectal cancer, predict prognostic survival, and guide adjuvant therapy. The detection rates of LVI and PNI were 32.1% and 16.1%. Differentiation grade, Union for International Cancer Control staging, tumor-lymph node-metastasis staging are significantly related to LVI or PNI. Multivariate logistic regression analysis shows that poor differentiation and N ≥ 1 can be used as independent risk factors and predictive factors for LVI. At the same time, poor differentiation and T > 3 is an independent risk factor for PNI. Only poor differentiation is the risk factor for poor prognosis in Cox risk regression analysis. In addition, the simultaneous occurrence of LVI and PNI is an independent prognostic factor.

Colorectal Carcinoma Growth Inhibition by Dietary Care Combined with Probiotic Intervention through Targeting NRP2 Expression

The present study investigated the effect of probiotics on inhibition of colorectal tumor growth in vivo and as anti-proliferative agent in vitro. Viability changes were measured by MTT assay whereas protein expression was assessed using western blotting. The study demonstrated that tumor growth was delayed significantly (P < 0.05) in probiotic administered mice from 2nd week compared to the control group. The difference in body weight of the mice in probiotic administered, 5-fluorouracil treated and untreated groups of the mice showed no significant differences during 5-weeks of the study. In probiotic administered mice the expression of miR-331-3p was significantly promoted and that of NRP2 effectively alleviated. Probiotic administration of the mice led to a significant (P < 0.05) increase in p53 and p-c-Jun expression and reduction in Bcl-2 level. Probiotic treatment of SW480 and HCT116 cells led to a significant (P < 0.05) reduction in viability after 48 h compared to the control cells. However, no changes were observed in FHC cell viability after 48 h of treatment with probiotics. The expression of miR-331-3p in SW480 and HCT116 cells was significantly promoted on treatment with probiotics after 48 h. Additionally, probiotic treatment for 48 h led to a remarkable reduction in NRP2 expression in SW480 and HCT116 cells. Thus, probiotic administration inhibited colorectal tumor growth in vivo in mice possibly by upregulation of miR-331-3p expression and down-regulation of NRP2 level. Therefore, probiotics may be used for the treatment of colorectal cancer growth.

Protease-activated receptor 2 stabilizes Bcl-xL and regulates EGFR-targeted therapy response in colorectal cancer

The Bcl-2 homolog Bcl-xL is emerging as a key factor in tumorigenesis due to its prominent pro-survival and cell death-independent functions. However, the regulation of Bcl-xL by microenvironment and its implication in cancer therapy of colorectal carcinoma (CRC) are unclear. Here, we demonstrated that Bcl-xL expression was positively associated with protease-activated receptor 2 (PAR2) in CRC. Activation of PAR2 stabilized Bcl-xL protein in a proteasome-dependent manner, whereas E3 ligase RING finger protein 152 (RNF152) accelerated the ubiquitination and degradation of Bcl-xL. RNF152 silencing by specific siRNAs rescued the expression of Bcl-xL in PAR2-deficient cells. Moreover, RNF152 physically interacted with Bcl-xL, which was disturbed by PAR2 activation. Further studies with serial mutation of Bcl-xL revealed that phosphorylation of Bcl-xL at S145 reduced its binding affinity for RNF152 and stabilized Bcl-xL. Importantly, inhibition of PAR2 signaling by its gene silencing or specific chemical inhibitors increased apoptosis induced by different EGFR-targeted therapies. In patient-derived xenograft model, inhibition of PAR2 increased the response of CRC to different EGFR-targeted therapies. These results indicate that PAR2 stabilizes Bcl-xL by altering RNF152 signaling and that PAR2 inhibition sensitizes CRC to EGFR-targeted therapies in vivo.

Limonoid compounds from Xylocarpus granatum and their anticancer activity against esophageal cancer cells

Background

To investigate the anticancer effects of limonoid compounds that were isolated and purified from Xylocarpus granatum fruits on human esophageal cancer (EC) cells. A structure‐activity relationship experiment was designed to identify the functional moiety of limonoid compounds identified as being critical for its anticancer activity.

Methods

Eca109 cells were cultured in RPMI1640 medium and treated with limonoid compounds. Cell proliferation was determined by the MTT assay in vitro. Eca109 cells apoptosis was analyzed by by flow cytometry after being treated with xylogranatin C. The expression of p53, Bax, bcl‐2, caspase‐3 and GRP78 in Eca109 cells after xylogranatin C treatment was examined by western blot assay.

Results

Four linonoid compounds strongly inhibited the cellular proliferation of Eca109 cells. Xylogranatin C was the strongest inhibitor, whose inhibitory effect was comparable to that of the well‐known chemotherapeutic agent, cisplatin. Furthermore, xylogranatin C might induce Eca109 cell apoptosis through joint effects on multiple pathways, including the death receptor and endoplasmic reticulum pathways. Additionally, xylogranatin C suppressed tumor cell proliferation by upregulating miR‐203a expression in Eca109 cells.

Conclusions

Xylogranatin C induced Eca109 cellular apoptosis and exerted antitumor activity. Xylogranatin C suppressed tumor cell proliferation by upregulating miR‐203a expression in Eca109 cells.

Correlation study of GAPDH, Bcl-2, and Bax protein immunoexpression in patients with colorectal adenocarcinoma

Introduction

Colorectal cancer (CRC) is the third and second most commonly diagnosed cancer worldwide in males and females, respectively. Despite prominent progress in diagnosis and treatment, the recurrence rates are still high. A tumour hypoxic environment leads to an increase in glycolytic metabolism. The crucial intermediate component of glycolysis, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), could play a significant role in cancer progression. An increased level of GAPDH has been described in oncogene-induced transformation and anti-apoptotic function. In other studies, GAPDH has been involved in apoptosis induction.

Aim

We examined colorectal adenocarcinoma samples to assess the immunoexpression of GAPDH protein. We also evaluated the correlation between the expression of GAPDH protein and apoptotic parameters including expression of Bcl2 and Bax.

Material and methods

Paraffin sections were incubated for 60 min with primary antibody against GAPDH, Bcl-2, and Bax.

Results

Results of our study have shown that GAPDH expression in colorectal cancer is upregulated. We revealed significant positive correlation between expression of this protein and grade and size of tumour, and regional lymph node involvement. In the case of apoptosis-associated proteins, e.g. Bcl-2 and Bax, we found negative correlations between expression of these proteins and grade and size of tumour, lymphovascular invasion, and regional lymph node involvement. Finally, we demonstrated that GAPDH up-regulation is connected with down-regulation in Bcl-2 and Bax.

Conclusions

Up-regulation of GAPDH protein and down-regulation of Bcl-2 and Bax may result in increased of cancer.

Segmental distribution of some common molecular markers for colorectal cancer (CRC): influencing factors and potential implications

Proximal and distal colorectal cancers (CRCs) are regarded as distinct disease entities, evolving through different genetic pathways and showing multiple clinicopathological and molecular differences. Segmental distribution of some common markers (e.g., KRAS, EGFR, Ki-67, Bcl-2, COX-2) is clinically important, potentially affecting their prognostic or predictive value. However, this distribution is influenced by a variety of factors such as the anatomical overlap of tumorigenic molecular events, associations of some markers with other clinicopathological features (stage and/or grade), and wide methodological variability in markers' assessment. All these factors represent principal influences followed by intratumoral heterogeneity and geographic variation in the frequency of detection of particular markers, whereas the role of other potential influences (e.g., pre-adjuvant treatment, interaction between markers) remains rather unclear. Better understanding and elucidation of the various influences may provide a more accurate picture of the segmental distribution of molecular markers in CRC, potentially allowing the application of a novel patient stratification for treatment, based on particular molecular profiles in combination with tumor location.

Genetic dissimilarity between primary colorectal carcinomas and their lymph node metastases: ploidy, p53, bcl-2, and c-myc expression--a pilot study

The current paradigm of metastasis proposes that rare cells within primary tumors acquire metastatic capability via sequential mutations, suggesting that metastases are genetically dissimilar from their primary tumors. This study investigated the changes in the level of expression of a well-defined panel of cell proliferation, differentiation, and apoptosis markers between the primary colorectal cancer (CRC) and the corresponding synchronous lymph node (LN) metastasis from the same patients. DNA flow cytometry and immunostaining of p53, bcl-2, and c-myc were carried out on 36 cases of CRC radical resection specimens with their corresponding LN metastases. There was very low probability that the histological patterns of primary tumors and LN metastases are independent (p < 0.001). Metastatic tumors were significantly more diffusely positive for p53 than the primary tumors (p < 0.001). Conversely, primary tumors were significantly more diffusely positive for c-myc than metastatic tumors (p = 0.011). No significant difference was found between the LNs and the primary tumors in bcl-2 positivity (p = 0.538) and DNA aneuploidy (p = 0.35), with a tendency towards negative bcl-2 and less aneuploidy in LN metastases than primary tumors. In conclusion, LN metastatic colorectal carcinomas have a tendency of being less differentiated, with a higher incidence of diffuse p53 staining, lower incidence of bcl-2 staining, and less aneuploidy in comparison to their primary counterparts suggesting a more aggressive biological behavior, which could indicate the necessity for more aggressive adjuvant therapy.

Expression of apoptosis regulating proteins identifies stage II and III colon cancer patients with high risk of recurrence

BACKGROUND AND OBJECTIVES

Deregulation of apoptosis related genes may be associated with poor outcome in cancer. Aim of the present study was to investigate the prognostic role of expression levels of apoptosis related proteins in stage II and III colon cancer.

METHODS

From tumor samples of 386 stage II and III colon cancer patients, DNA was isolated and tissue microarrays were constructed. Expression of Bcl-2, Bcl-X, BAX, XIAP, Fas, FasL and c-FLIP was evaluated and PCR-based microsatellite instability analysis was performed.

RESULTS

High FasL expressing tumors were associated with high disease recurrence rates in stage II colon cancer patients overall, as was low Bcl-X expression in microsatellite stable stage II patients. In stage II patients, a multivariable model based on FasL and Bcl-XL expression revealed a significant association with disease free survival (DFS). In stage III colon cancer patients, low Bcl-2, low BAX and low Fas expression levels were associated with worse outcome. In these patients a multivariable model based on angioinvasion and Bcl-2, Fas and FasL expression was significantly associated with DFS.

CONCLUSIONS

Stage II patients with low Bcl-X and high FasL protein expression levels and stage III patients with low Fas, high FasL and low Bcl-2 expression could be considered as high risk for disease recurrence.

Expression of apoptosis-related Bcl-2-family and P53 in human adenocarcinoma of the pancreas

AIM: To investigate the relationships between P53 and Bcl-2 family (Bcl-2, Bax, Bcl-xL, Bcl-xS) expression and apoptosis in human pancreatic carcinoma (PC).

METHODS: The immunohistochemical method was used to detect the expression of P53 protein in a total of 35 patients with PC. The patients were divided into two groups, group 1 with immunonegative P53 (18 cases) and group 2 with immunopositive (17 cases). The expressions of P53, Bcl-2, Bax, Bcl-xL, and Bcl-xS in both groups were detected by Western blot. The apoptosis index (AI) of group 1 was determined by terminal deoxynucleotidyltransferase-mediated UTP end-labeling (TUNEL).

RESULTS: Bcl-2 was remarkably up-regulated in group 2 but down-regulated in group 1 (P = 0.047). Expressions of both Bax and Bcl-xL proteins were up-regulated in those two groups (P = 0.274, 0.334). Bcl-xS was remarkably down-regulated in group 2 but up-regulated in group1 (P = 0.01). The AI of both groups were 12.1 ± 2.47 and 9.1 ± 1.48, respectively (P = 0.023), no correlations were found between AI and expression of Bcl-2 family members, but marked correlations were noted between AI and the Bcl-2/bax ratios (P < 0.01).

CONCLUSION: Bcl-2 family is a group of anti-apoptotic proteins, and Bcl-xS is a pro-apoptotic protein. Both of them are dependent on the regulation of P53 which modulates apoptosis mainly through modifying Bcl-2/Bax ratios.

Apoptosis signaling proteins as prognostic biomarkers in colorectal cancer: a review

Colorectal cancer is a leading cause of cancer related mortality in the Western world. In recent years, combination 5-fluorouracil based adjuvant chemotherapy as first line treatment of this disease has led to improved disease free and overall survival. However drug resistance, both innate and acquired, remains an obstacle in the effective treatment of this disease. Apoptotic pathways are frequently altered in both tumor progression and drug resistance; therefore proteins associated with this pathway may have potential as prognostic biomarkers for this disease. Identification of clinical biomarkers that are able to identify patients who are more likely to respond to specific chemotherapy will lead to more personalized, effective, and less toxic therapy. This review focuses on the current status of apoptosis related proteins as biomarkers for colorectal cancer and discusses the possible application of systems approaches in this context.

P53 and bcl-2 in colorectal cancer arising in patients under 40 years of age: distribution and prognostic relevance

Young people (40 years of age) with colorectal cancer (CRC) represent a distinct subgroup with more aggressive disease behaviour compared to older patients. We evaluate whether p53 and bcl-2 could be useful in identifying young patients at higher risk of tumour progression. We reviewed 1340 CRC patients with 58 patients 40 years (4.2%). They had more frequent moderately or poorly differentiated mucinous adenocarcinomas (26% versus 12.3%, p=0.03); higher advanced stage at diagnosis; shorter 5-year overall survival (49.8% versus 71%; p=0.02); more frequent p53 positive (89.8% versus 72.6%, p<0.05) and bcl-2 negative (88.0% versus 66.2%, p<0.05) tumours; no difference in DNA content or proliferation indexes. Moreover, p53+ and bcl-2- resulted in being independent predictors of survival with shorter survival for the p53+/bcl-2- patients. Combining p53 and bcl-2, we could identify young CRC patients at higher risk of progression, who probably require development of a more sophisticated therapeutic approach based on identification of predictive factors.

Research progress in anti-apoptosis gene Bcl-xL

Apoptosis is a physiological process that an organism selectively eliminates cells that are no longer needed, or have been damaged, or are dangerous. Bcl-xL, an important member of the Bcl-2 family that plays indispensable roles in regulating cell survival and apoptosis, is frequently over-expressed in various kinds of human cancers. The inhibition of this molecule is associated with decreased tumorigenesis and resistance to conventional chemotherapy. This article briefly reviews some progresses in the study of Bcl-xL in the past few years.

Potential role of apoptosis and apoptotic regulatory proteins in colorectal neoplasia: correlations with clinico-pathological parameters and survival

An imbalance between apoptotic and proliferative processes is believed to underlie colorectal neoplasia. We evaluated the expression of bcl-2, p53, mdm2 proteins, and apoptosis in colorectal neoplasms, as well as their correlation with clinico-pathological parameters, using image analysis. Biopsies from 46 colorectal cancers, 121 adenomas, and 25 controls were studied using monoclonal antibodies against p53, bcl-2, mdm2 and the terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling (TUNEL) method for apoptosis. P53 and bcl2 protein expression was higher in adenomas >or=1 cm (P < 0.03) and tubulovillous-villous adenomas (P < 0.03), and correlated with dysplasia (P < 0.03). In Cox regression analysis, Dukes' stage was the most significant independent prognostic indicator of a worse survival (P < 0.019), whereas when stage was eliminated, bcl-2 expression was also a powerful predictor for bad prognosis (P = 0.02). In conclusion, both bcl-2 and p53 immunohistochemical profiles may be useful adjuncts in detecting adenomas with a malignant potential, whereas bcl-2 could be used in combination with Dukes' stage as a predictor of prognosis in colorectal cancer.

Inhibition of human gastric carcinoma cell growth by treatment of N(3)-o-toluyl-fluorouracil as a precursor of 5-fluorouracil

N(3)-o-toluyl-fluorouracil (TFU), the pro-drug of 5-fluorouracil (5-FU), is the metabolite of N(1)-acetyl-N(3)-o-toluyl-fluorouracil (atofluding). We aimed to evaluate the efficacy of TFU as a precursor of 5-FU on the growth inhibition of human gastric carcinoma cell lines SGC-7901 and MKN-45. Growth of SGC-7901 and MKN-45 cells was remarkably suppressed by treatment with TFU in the presence of liver microsomal enzymes in vitro, suggesting that TFU may be converted to 5-FU by the enzymes. Similar treatment of TFU induced apoptosis of the cells, which was deduced from typical apoptotic features such as morphology, the formation of characteristic ladder pattern of DNA migration and the accumulation of sub-G1 phase. Cancer cells xenografts in nude mice were employed to evaluate the efficacy of TFU in vivo. Growth of human gastric carcinoma cells was significantly delayed by oral administration of TFU with low side effects. Apoptosis in xenografts was also observed by means of TUNEL staining method. These results suggest that the treatment of TFU in the presence of liver microsomal enzymes and the oral administration of TFU in mice induced anti-proliferation and apoptosis in gastric carcinoma cells. This suggests that TFU may be a promising pro-drug of 5-FU for cancer treatments.