Effectively α-Terpineol Suppresses Glioblastoma Aggressive Behavior and Downregulates KDELC2 Expression.

BACKGROUND: Glioblastoma (GBM) is notorious for the aggressive behaviors and easily results in chemo-resistance. Studies have shown that the use of herbal medicines as treatments for GBM as limited by the blood-brain barrier (BBB) and glioma stem cells. PURPOSE: The aim of this study was to investigate the relationship between GBM suppression and α-terpineol, the monoterpenoid alcohol derived from Eucalyptus glubulus and Pinus merkusii. STUDY DESIGN: Using serial in-vitro and in-vivo studies to confirm the mechanism of α-terpineol on down-regulating GBM development. METHODS: The 3-[4,5-dimethylthiazol-2-yl)]-2,5-diphenyltetrazolium bromide (MTT) assay was performed to evaluate IC50 of α-terpineol to inhibit GBM cell survival. In order to evaluate the impact of GBM aggressive behaviors by α-terpineol, the analysis of cell migration, invasion and colony formation were implemented. In addition, the ability of tumor spheres and WB of CD44 and OCT3/4 were evaluated under the impression of α-terpineol decreased GBM stemness. The regulation of neoangiogenesis by α-terpineol via the WB of angiogenic factors and human umbilical vein endothelial cells (HUVEC) tube assay. To survey the decided factors of α-terpineol downregulating GBM chemoresistance depended on the impact of O6-methylguanine-DNA methyltransferase (MGMT) expression and autophagy-related factors activation. Additionally, WB and quantitative real-time polymerase chain reaction (qRT/PCR) of KDEL (Lys-Asp-Glu-Leu) containing 2 (KDELC2), endoplasmic reticulum (ER) stress, phosphoinositide 3-kinase (PI3k), mammalian target of rapamycin (mTOR) and mitogen-activated protein kinase (MAPK) cascade signaling factors were examined to explore the mechanism of α-terpineol inhibiting GBM viability. Finally, the orthotopic GBM mouse model was applied to prove the efficacy and toxicity of α-terpineol on regulating GBM survival. RESULTS: α-terpineol significantly suppressed GBM growth, migration, invasion, angiogenesis and temozolomide (TMZ) resistance. Furthermore, α-terpineol specifically targeted KDELC2 to downregulate Notch and PI3k/mTOR/MAPK signaling pathway. Finally, we also demonstrated that α-terpineol could penetrate the BBB to inhibit GBM proliferation, which resulted in reduced cytotoxicity to vital organs. CONCLUSION: Compared to published literatures, we firstly proved α-terpineol possessed the capability to inhibit GBM through various mechanisms and potentially decreased the occurrence of chemoresistance, making it a promising alternative therapeutic option for GBM in the future.

Low Expression of A3C and PLP2 Indicating a Favorable Prognosis in Human Gliomas.

The roles of apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3C (A3C) in various human malignancies are not consistent. A3C expression is correlated with early-stage breast cancer and is presented as a good prognostic factor; however, it induces fewer therapeutic effects of cytotoxic drugs in low-grade gliomas. To explore the impact of A3C on gliomas, a statistical analysis of several public databases was conducted. The results showed that enhanced A3C expression was associated with advanced tumor grades and poor expression of prognostic factors. Similarly, our in vitro study revealed that glioblastoma (GBM) cell lines had higher A3C mRNA and protein expression than that of normal brain tissue cDNA and lysates. We first performed an immunohistochemical stain (IHC) to prove that gliomas with high A3C expression presented the wild type-Isocitrate dehydrogenase 1 (IDH1), and they had an unfavorable prognosis in human glioma tissues. In addition, the oncological factors associated with A3C expression suggested that DNA repair pathways are important mechanisms for inducing tumorigenesis and chemoresistance in gliomas. Moreover, a significant correlation was observed between A3C expression and proteolipid protein 2  (PLP2). Reactive oxygen species (ROS) -activated PLP2 prevents DNA damage-induced cell apoptosis. Compared to high immunostaining scores for A3C and/or PLP2 expression, combined low immunostaining scores for A3C and PLP2 correlated with improved survival in gliomas; however, the detailed mechanism is to be elucidated. In conclusion, our results not only confirmed A3C played an important role in glioma development, but the A3C IHC test could successfully predict the therapeutic effects and disease prognosis.

Impact of prostatic anterior fat pads with lymph node staging in prostate cancer.

Background: Several reports have revealed the presence of lymph nodes in the prostatic anterior fat pad (PAFP). To date, no study has described the characteristics of Taiwanese patients harboring PAFP lymph nodes with metastatic prostate cancer involvement. Method: Between December 2006 and May 2015, a total of 849 consecutive patients underwent robot-assisted laparoscopic radical prostatectomy with PAFP dissection. Pathological examination of the dissected PAFP was conducted to assess the presence of lymphoid tissue and prostate cancer involvement. Results: Of the 849 patients, 76 (9.0%) had 1-3 PAFP lymph nodes. Moreover, 11 (1.3%) of the 76 patients had positive lymph node metastases of prostate cancer in the PAFP; 5 (0.6%) of the 11 patients, who had negative pelvic lymph node involvement, were upstaged because of positive metastases in PAFP lymph nodes. Among the 76 patients having PAFP lymph nodes, metastatic lymph nodes were associated with the clinical T stage, preoperative Gleason score, pathological T stage, and pathological N stage (p < 0.001). Patients with pathological seminal vesicle invasion and a higher surgical Gleason score also exhibited PAFP lymph node metastases (p < 0.005). Conclusion: Our data show that 9.0% of patients had PAFP lymph nodes and that 1.3% had prostate cancer metastases. Additionally, 0.6% of patients were upstaged because of positive metastases in PAFP lymph nodes. Because of the pathological analysis of the PAFP, a few patients were upstaged. Thus, routine pathological analysis of the PAFP should only be conducted for those with higher preoperative prostate-specific antigen, higher Gleason score, and advanced T stage observations.

Impaired Gut Epithelial Tight Junction Expression in Hemodialysis Patients Complicated with Intradialytic Hypotension.

BACKGROUND: There is accumulating evidence pointing to uremia-induced impairment of the intestinal epithelial barrier structure in advanced chronic kidney disease (CKD) and hemodialysis (HD) patients. In this study, the impact of intradialytic hypotension on intestinal barrier integrity is being explored. METHODS: Immunohistochemical staining was used to detect the expression of 4 types of tight junction (TJ) proteins such as occludin, zonula occludens-1 (ZO-1), claudin-1, and claudin-4, in colonic samples of a group of patients receiving segmental colectomy. Five patients with nondialysis CKD (group 2), 5 HD patients with intradialytic hypotension (group 3), and 5 non-CKD subjects (group 1) were examined. RESULTS: Both patients' groups 2 and 3 demonstrated significantly reduced expression of occludin as compared to group 1 (p < 0.05 and p < 0.01, resp.). Except for claudin-4, expression of all markers of TJ proteins was significantly reduced in patients' group 3 as compared to control (p < 0.01). In addition, decreased expressions of claudin-1 and ZO-1 were also more pronounced in group 3 when compared to group 2. CONCLUSIONS: This study extends the earlier finding by demonstrating that dialysis-related hypotension caused even marked depletion of the key protein constituents of the epithelial TJ.

The detection of tumor location and lymph node metastasis by aberrant NXPH1 and NXPH2 expressions in pancreatic ductal adenocarcinomas.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease associated with a poor prognosis and high morbidity. Early diagnosis and complete tumor removal are still the principal factors extending life expectancy in PDAC patients. Here, the relationship of neurexophillin 1 (NXPH1) and NXPH2 expressions with clinicopathological parameters of PDAC was evaluated. Immunohistochemical analysis of NXPH1 and NXPH2 was performed in one tissue microarray of 96 surgical specimens, including normal pancreatic duct tissue (n = 5), PDACs at various stages of differentiation (n = 77), and pancreatic neuroendocrine tumors (n = 14). The intensity of both NXPH1 and NXPH2 staining was weak in only a small proportion of benign pancreatic ductal epithelial cells and was significantly higher in most PDAC specimens than in non-neoplastic pancreatic tissue specimens. However, no correlation of the expression of these PDAC biomarkers with tumor grades, T, N, and American Joint Committee on Cancer (AJCC) pathologic stages was established. Contrary to our expectation, the immunohistochemical results of NXPH1 and NXPH2 were inversely correlated with N stage in PDAC. NXPH1 and NXPH2 as PDAC biomarkers may be used to identify patients with this tumor, help delineate appropriate surgical margins, and identify lymph node metastasis in imaging studies.

Differentiating gastrointestinal stromal tumors from gastric adenocarcinomas and normal mucosae using confocal Raman microspectroscopy.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract, and gastric adenocarcinomas are a common cancer worldwide. To differentiate GISTs from adenocarcinomas is important because the surgical processes for both are different; the former excises the tumor with negative margins, while the latter requires radical gastrectomy with lymph node dissection. Endoscopy with biopsy is used to distinguish GISTs from adenocarcinomas; however, it may cause tumor bleeding in GISTs. We reported here the confocal Raman microspectroscopy as an effective tool to differentiate GISTs, adenocarcinomas, and normal mucosae. Of 119 patients enrolled in this study, 102 patients underwent gastrectomy (40 GISTs and 62 adenocarcinomas), and 17 patients with benign lesions were obtained as normal mucosae. Raman signals were integrated for 100 s for each spot on the specimen, and 5 to 10 spots, depending on the sample size, were chosen for each specimen. There were significant differences among those tissues as evidenced by different Raman signal responding to phospholipids and protein structures. The spectral data were further processed and analyzed by using principal component analysis. A two-dimensional plot demonstrated that GISTs, adenocarcinomas, and normal gastric mucosae could be effectively differentiated from each other.

Novel Method for Differentiating Histological Types of Gastric Adenocarcinoma by Using Confocal Raman Microspectroscopy.

Gastric adenocarcinoma, a single heterogeneous disease with multiple epidemiological and histopathological characteristics, accounts for approximately 10% of cancers worldwide. It is categorized into four histological types: papillary adenocarcinoma (PAC), tubular adenocarcinoma (TAC), mucinous adenocarcinoma (MAC), and signet ring cell adenocarcinoma (SRC). Effective differentiation of the four types of adenocarcinoma will greatly improve the treatment of gastric adenocarcinoma to increase its five-year survival rate. We reported here the differentiation of the four histological types of gastric adenocarcinoma from the molecularly structural viewpoint of confocal Raman microspectroscopy. In total, 79 patients underwent laparoscopic or open radical gastrectomy during 2008-2011: 21 for signet ring cell carcinoma, 21 for tubular adenocarcinoma, 14 for papillary adenocarcinoma, 6 for mucinous carcinoma, and 17 for normal gastric mucosas obtained from patients underwent operation for other benign lesions. Clinical data were retrospectively reviewed from medical charts, and Raman data were processed and analyzed by using principal component analysis (PCA) and linear discriminant analysis (LDA). Two-dimensional plots of PCA and LDA clearly demonstrated that the four histological types of gastric adenocarcinoma could be differentiated, and confocal Raman microspectroscopy provides potentially a rapid and effective method for differentiating SRC and MAC from TAC or PAC.

Positive cyclin T expression as a favorable prognostic factor in treating gastric gastrointestinal stromal tumors.

Positive transcriptional elongation factor b (P-TEFb) contains the catalytic subunit cyclin-dependent kinase 9 (Cdk9) and the regulatory subunit cyclin T. Cyclin T1 and Cdk9 are the key factors of the PTEFb pathways and are overexpressed in the human head and neck carcinoma cell line. However, there have been limited studies regarding the role of cyclin T1 and Cdk9 in gastric gastrointestinal stromal tumors (GISTs). The aim of the present study was to assess the association between cyclin T1 and Cdk9 and their clinical significance in gastric GISTs. A total of 30 gastric GIST patients who underwent either laparoscopic or laparotomic partial gastrectomy were enrolled in the study. The surgical tissue slides were stained with Cdk9 and cyclin T1 antibodies, and the immunohistochemistry scores and disease-free survival (DFS) were analyzed. Ten patients were cyclin T1-positive, and 20 were negative. All 11 patients with recurrent tumors or distant metastases were cyclin T1-negative patients. Old age, large tumor size, a high Ki67 IHC staining score, high mitotic count and negative cyclin T1 staining revealed a worse clinical outcome in univariate analysis. By contrast, the Cdk9 score was not associated with clinical parameters. The Kaplan-Meier survival curve illustrated that the DFS rate of the patients with negative cyclin T1 staining was significantly lower than that of the patients with positive cyclin T1 staining. Positive expression of cyclin T1 was a good prognostic factor in patients with gastric GISTs.

Increased cyclin T1 expression as a favorable prognostic factor in treating gastric adenocarcinoma.

The expression of cyclin A, B1, D1 and E in gastric adenocarcinoma is known to be associated with clinical outcome. However, few studies have investigated the role of cyclin T1 and cyclin-dependent kinase 9 (CDK9) in gastric adenocarcinoma. Therefore, this study assessed the clinical significance of cyclin T1 and CDK9 expression in gastric adenocarcinoma. A total of 39 gastric adenocarcinoma patients received either radical total or distal gastrectomy in this study. Surgical tissue slides were stained with CDK9 and cyclin T1 antibodies, and immunohistochemistry scores and disease-free survival (DFS) rates were analyzed. Among the 19 patients with tumor-recurrent or distant metastasis, 16 were recorded as exhibiting low expression of cyclin T1. The remaining three patients exhibited high expression of the antibody. The results of patients with a higher T stage, N stage and tumor grade were less favorable. For patients with adenocarcinoma, the percentage of tissue slides stained with cyclin T1 was significantly higher than for those with normal stomach epithelia. The DFS rates of patients with low expression of cyclin T1 were significantly associated with poorer DFS rates. In conclusion, high expression of cyclin T1 is a favorable prognostic factor in treating patients with stomach adenocarcinoma.

Secondary pulmonary conventional chordoma arising from primary sarcomatoid chordoma of the sacrum: A case report.

Chordomas are low- to intermediate-grade malignant tumors that recapitulate the notochord. Chordomas belong to the dysontogenetic bone tumors and appear primarily in the region of the axial skeleton. Chordomas are divided into conventional, chondroid, sarcomatoid and dedifferentiated subtypes. The different subtypes of chordoma have varied survival periods. According to the literature to date, secondary pulmonary and lymph-node metastases occur most frequently, followed by liver, bone and skin metastases. To the best of our knowledge, there has been no previous report of one subtype of chordoma metastasizing or transforming into another subtype with a different histopathology. This study presents a 24-year-old man with secondary pulmonary conventional chordoma arising from a primary sarcomatoid chordoma of the sacrum. The patient was alive at the end of November, 2009 and the survival time exceeded eight years. This is the first case of a patient with primary sarcomatoid chordoma of the sacrum with complete remission in whom a secondary pulmonary conventional chordoma arose from the primary cancer.

The association of urocortin expression with clinicopathologic parameters of gastric adenocarcinomas.

Gastric adenocarcinoma is a lethal disease with high incidence in Chinese people. The purpose of this study was to evaluate the expression of urocortin (UCN) in normal gastric mucosa and gastric adenocarcinomas. Immunohistochemical analysis of UCN was performed in 112 surgical specimens (21 normal gastric mucosa specimens and 91 gastric adenocarcinoma specimens varying in histologic grade and pathologic stage). Immunostain intensity was scored on a scale ranging from 0 (absence of staining) to 3 (strong staining). The percentage of UCN stained cells was scored on a scale ranging from 0 (<5%) to 4 (75% to 100%). The UCN immunoscore (ranging from 0 to 12) was the product of the above 2 scores. The UCN immunoscore was high in all 9 normal gastric mucosa specimens, significantly lower in poorly differentiated gastric adenocarcinoma than in well and moderately differentiated tumors (P=0.018), and significantly lower in more advanced pathologic stages of gastric adenocarcinomas than in the early stages of these tumors. Moreover, UCN expression was higher in gastric adenocarcinomas with neuroendocrine differentiation than in mucinous adenocarcinomas and signet-ring cell carcinomas. In conclusion, UCN is expressed in most non-neoplastic gastric glandular epithelia. However, UCN expression inversely correlates with higher tumor grade and advanced TNM stage in gastric adenocarcinomas.

Expression of urocortin in pancreatic ductal adenocarcinoma and pancreatic intraepithelial neoplasia.

Urocortin (UCN) is a 40-amino acid neuropeptide that regulates angiogenesis and inhibits cell proliferation. Our aim was to examine the relationship of UCN expression to the clinicopathological parameters of pancreatic ductal adenocarcinoma (PDAC) and histological grade of pancreatic intraepithelial neoplasia (PanIN). Tissue microarray was used to analyze UCN protein expression in 89 surgical specimens including 21 PanIN, 3 PDAC arising from PanIN, and 65 PDAC without PanIN. UCN immunoscores ranging from 0 to 12 were obtained by multiplying intensity (scored on a 3-point scale) by the percentage of stained cells (scored on a 4-point scale). Strong expression of UCN was detected in 5 specimens of non-neoplastic pancreatic ductal epithelia. UCN immunoscore was significantly higher in PanIN-1 than in PanIN-2 and PanIN-3 (p = 0.038) and significantly higher in well-differentiated PDAC or early American Joint Committee on Cancer (AJCC) stage PDAC than in poorly differentiated or advanced stage PDAC (p = 0.025, p = 0.018). Higher expression of UCN correlates with PDAC tumor grade and AJCC pathologic stage as well as PanIN grade. Immunohistochemical assessment of UCN may help clinicians predict tumor recurrence rate and help pathologists make a proper diagnosis.

Inflammatory fibroid polyp of rectum mimicking rectal cancer.

Inflammatory fibroid polyps (IFPs) are rare benign tumors of the rectum. Mutation and activating platelet-derived growth factor receptor alpha (PDGFRA) contribute to tumor development. We present a case of IFPs in the middle rectum that mimic rectal cancer. A 65-year-old woman presented with the symptom of fresh blood in the stool and body weight loss of 6 kg in the preceding 3 weeks. A rectal polypoid tumor was noted upon digital examination. Sigmoidoscopy showed a middle rectal tumor measuring 3 × 2.7 cm with obstruction. Computed tomography (CT) scans of the abdomen showed a rectal tumor that had invaded the sacral bone and was associated with four enlarged lymph nodes greater than 1 cm. The radiological report suggested a diagnosis of rectal cancer with lymph node metastases. To remove the obstruction, the patient was initially treated with excision of the tumor and loop sigmoidal colostomy to the abdomen wall. Total mesorectal resection of rectal and sacral tumor followed 10 days later. Histopathological examination of the rectal and sacral tumor showed proliferation of vessels, fibroblast-like spindle cells, and mixed inflammatory cells, including the plasma cells and eosinophils. The spindle cells were diffusely positive to PDGFRA and were focal positive to CD34 and smooth muscle actin. Based on histopathological and immunohistochemical findings, the diagnosis of IFP is indicated. This was the first reported case of IFPs of the rectum presenting with lymph node enlargement and attachment to the sacrum mimicking rectal cancer.

The correlations of LMX1A and osteopontin expression to the clinicopathologic stages in pancreatic adenocarcinoma.

AIM: To test the association of LMX1A and osteopontin (OPN) expression with histologic differentiation or pathologic stage in pancreatic ductal adenocarcinoma. METHODS: Immunohistochemical analysis was performed to determine LMX1A and OPN expression in 100 surgical specimens obtained from Chinese patients with well-differentiated (n=15), moderately differentiated (n=65), and poorly differentiated (n=20) pancreatic ductal adenocarcinomas. RESULTS: LMX1A and OPN immunoreactivities were undetectable in normal pancreatic glandular epithelia. Stronger immunostaining for LMX1A and OPN was associated with advanced nuclear grades of pancreatic ductal adenocarcinomas (70.7 and 87.1 for grade I, 109.8 and 118.3 for grade II, and 171.3 and 183.8 for grade III), and advanced TNM and American Joint Committee on Cancer stages of pancreatic ductal adenocarcinomas. CONCLUSIONS: A higher expression of LMX1A and OPN is well correlated with histologic grade and pathologic stage of pancreatic ductal adenocarcinomas.

The correlation of cortactin and fascin-1 expression with clinicopathological parameters in pancreatic and ampulla of Vater adenocarcinoma.

Cortactin and fascin-1 are important factors affecting progression and metastasis of carcinomas. We tested the hypothesis that cortactin and fascin expression has significant correlation with clinicopathological parameters in pancreatic and ampulla of Vater adenocarcinomas. Immunohistochemical analysis of cortactin and fascin-1 was performed in 50 pancreatic and 40 ampulla of Vater adenocarcinomas. The specimens were from 29 R0, 8 R1, and 13 palliative resections of pancreatic adenocarcinomas and 18 R0, 14 R1, and 8 palliative resections of ampulla of Vater adenocarcinomas. 'R0' resection is defined by complete removal of the tumor and histologically negative surgical margins and 'R1' resection indicates the presence of microscopically residual disease at the surgical margins. The level of expression was assessed by scoring the intensity of cytoplasmic or membranous immunostaining on a 4-point scale. Higher immunostaining scores of cortactin and fascin-1 were both significantly correlated with histological grade, American Joint Committee on Cancer (AJCC) stage, and survival rate in all patients. In conclusion, overexpression of cortactin and fascin-1 implies poorer tumor differentiation, advanced AJCC stage, and shorter survival rate in pancreatic and ampulla of Vater adenocarcinomas.

Cytoplasmic CD133 expression is a reliable prognostic indicator of tumor regression after neoadjuvant concurrent chemoradiotherapy in patients with rectal cancer.

BACKGROUND: Despite development in therapeutic strategies, such as neoadjuvant concurrent chemoradiotherapy (CCRT), the prognosis of colorectal cancer remains relatively poor. Cancer stem cells (CSC) with several characteristics can lead to therapeutic resistance. CD133 has been identified as a putative CSC marker in colorectal cancer; however, its functional role still needs elucidation. We verified the role of CD133 with emphasis on expression location and correlated the results of CD133 with clinical outcome in colorectal cancer. METHODS: We used immunohistochemistry to investigate the expression of CD133 in samples from 157 patients with colonic adenocarcinoma and from 76 patients with rectal adenocarcinoma who received neoadjuvant CCRT. We also correlated the expression location of CD133 with the clinicopathological parameters and prognosis. RESULTS: CD133 protein was variably overexpressed in colorectal cancer tissues and was present in three locations: apical and/or endoluminal surfaces, cytoplasm, and lumen. Cytoplasmic CD133 expression level correlated significantly with tumor local recurrence (P = 0.025) and survival of patients with colorectal cancer (P = 0.002), and correlated inversely with tumor regression grading (P = 0.021) after CCRT in patients with rectal cancer. CONCLUSIONS: The expression of CD133 in the cytoplasm is closely associated with local recurrence and patient survival, and may provide a reliable prognostic indicator of tumor regression grading in patients with rectal cancer after CCRT. Cytoplasmic CD133 expression may also help identify the surviving cancer cells in areas with nearly total regression after CCRT.

Solitary gastric Peutz-Jeghers type stomach polyp mimicking a malignant gastric tumor.

Most cases of Peutz-Jeghers type polyps of the stomach are associated with mucocutaneous pigmentation and multiple intestinal polyposis. A solitary Peutz-Jeghers type polyp of the stomach is rare. We here report a case of a 71-year-old woman with a solitary Peutz-Jeghers type polyp of the stomach who presented with intolerable epigastric pain and weight loss of 5 kg over the prior two months. During the hospital treatment course for this patient, endoscopic examination revealed a bulging lesion with a central hole, mucosal ulceration, an asymmetrical wall thickness and a narrowing of the gastric lumen. A gastric biopsy further revealed ulceration with moderate dysplasia. The patient received endoscopic ultrasonography which showed a second subepithelial lesion that measured 4 cm × 3 cm. Computed tomography of the abdomen subsequently showed a thickened gastric wall with three visibly enlarged lymph nodes, all greater than 1 cm. The suspected diagnosis was malignant gastric cancer with lymph node metastases. The other lesion, which measured 2 cm × 2 cm × 1 cm was noted in the submucosa of the jejunum during surgery. The patient was treated using a subtotal gastrectomy and partial resection of the jejunal tumor. The final pathological report indicated a gastric Peutz-Jeghers type polyp with proliferation of smooth muscle bundles in the submucosal layer, and hyperplastic glands in the mucosal layer and ectopic pancreas of the jejunum. This is the first reported clinical case of a solitary Peutz-Jeghers type polyp of the stomach accompanying a lymph node enlargement and ectopic pancreas in the jejunum that simulates stomach cancer with lymph node metastases.

SAHA inhibits the growth of colon tumors by decreasing histone deacetylase and the expression of cyclin D1 and survivin.

We studied the effects of suberoylanilide hydroxamic acid (SAHA), a histone deacetylase (HDAC) inhibitor, on colon cancer. The expression of HDACs in colorectal cancer specimens and the effects of SAHA on colon cancer cells and tumors of nude mice were assessed. Treatment with SAHA (3 µm) for 72 h induced downregulation of different subtypes of HDAC proteins and also induced acetylation of histone 3 and histone 4. SAHA significantly inhibited the expression of the oncogenic protein c-myc and also increased the expression of the p53 and Rb proteins. The immunohistochemical staining of HDACs, including HDAC1, HDAC2, HDAC3, and HDAC4, was significantly increased in colorectal adenocarcinoma specimens compared to healthy control tissues. In addition, murine studies showed that 100 mg/kg SAHA administered by intraperitoneal injection significantly induced tumor necrosis and inhibited the growth of colon tumors. Immunohistochemistry of the tumor tissues from nude mice revealed that SAHA inhibited the expression of different subtypes of histone deacetylase, the anti-apoptotic proteins cyclin D1, survivin, and also inhibited cell proliferative as determined by Ki67 expression. SAHA inhibited the growth of colon tumors by decreasing histone deacetylases and the expression of cyclin D1 and survivin in nude mice.