Cyclin D1和p16、p27在脑胶质瘤中的表达及其与PCNA的相关性

目的 :检测CyclinD1 和p16、p2 7以及PCNA在脑胶质瘤中的表达状况 ,以探讨不同病理类型脑胶质瘤中各自的表达及其相关性。方法 :应用免疫组化S P法 ,检测 12例正常脑组织、5 8例脑胶质瘤组织中CyclinD1 、p16、p2 7及PCNA表达及其特征。结果 :CyclinD1 在由低度恶性胶质瘤向高度恶性胶质瘤转化中阳性表达逐渐增强 (χ2 检验 ,P <0 0 0 5 ,χ2 =5 1 6 7) ;而p16、p2 7阳性表达却是随着胶质瘤恶性程度的升高而降低 (χ2 检验 ,P值均 <0 0 0 5 ,χ2 分别为 15 4 1和 12 81)。CyclinD1 与PCNA呈正相关 ,rs =0 74 5 ;p16和p2 7与PCNA呈负相关 ,rs分别为 - 0 5 6 6和 - 0 6 12。结论 :脑胶质瘤中CyclinD1的表达程度对胶质瘤的细胞增殖活性起促进作用 ,而p16、p2 7的表达则起抑制作用。     

Expression of pRb, p53, p16 and cyclin D1 and their clinical implications in urothelial carcinoma

The aim of this study was to assess immunohistochemical expression of p53, pRb, p16, and cyclin D1, alone or in combination, as prognostic indicators and to investigate their correlation with clinocopathologic features of urothelial carcinoma. Immunohistochemical staining for p53, pRb, p16, and cyclin D1 was performed on a tissue microarray from 103 patients with urothelial carcinoma who underwent radical cystectomy. Of the patient samples analyzed, 36 (35%), 61 (59%), 47 (46%) and 30 (29%) had altered expression of p53, pRb, p16, and cyclin D1, respectively. Abnormal expression of p53 and pRb correlated with depth of invasion (P=0.040 and P=0.044, respectively). Cyclin D1 expression was associated with tumor stage and recurrence (P=0.017 and P=0.036, respectively). Altered pRb was significantly correlated with overall survival (P=0.040). According to the expression pattern of pRb and p53, p53/pRb (altered/normal) had worse survival than p53/pRb (normal/altered) (P=0.022). Alteration of all markers had worse survival than all normal (P=0.029). As determined by multivariate analysis, tumor stage, lymph node metastasis and the combined expression of p53 and pRb are independent prognostic factors. In conclusion, immunohistochemical evaluation of cell cycle regulators, especially the p53/pRb combination, might be useful in planning appropriate treatment strategies.     

stathmin和P27kip1在大肠癌中的表达及意义

目的:探讨stathmin蛋白与p27kip1蛋白在大肠癌组织中的表达及意义.方法:应用免疫组织化学SABC法检测25例正常大肠黏膜组织、25例大肠腺瘤组织、47例大肠癌组织中stathmin蛋白及p27kip1蛋白的表达情况.结果:①stathmin蛋白在正常大肠黏膜组织、大肠腺瘤组织及大肠癌组织中的阳性表达率分别为20％、48％、74.47％;正常大肠黏膜组分别与大肠腺瘤组及大肠癌组比较,差异均有统计学意义(P＜0.05);大肠腺瘤组与大肠癌组比较,差异亦有统计学意义(P＜0.05):stathmin蛋白的表达与肿瘤的分化程度、有无淋巴结转移及TNM分期显著相关(P＜0.05).②p27kap1蛋白在正常大肠黏膜组织、大肠腺瘤组织及大肠癌组织中的阳性表达率分别为92％、80％、31.91％.正常大肠黏膜组与大肠癌组比较,差异有统计学意义(P＜0.05);大肠腺瘤组与大肠癌组比较,差异亦有统计学意义(P＜0.05);正常大肠黏膜组与大肠腺瘤组比较,差异无统计学意义(P＞ 0.05);p27kip1蛋白的表达与肿瘤的分化程度及淋巴结转移有关(P＜0.05).③stathmin蛋白的表达与p27kip1蛋白的表达呈负相关(r=--0.695 3,P＜0.01).结论:stathmin蛋白在大肠癌组织中高表达,其表达程度与肿瘤的分化程度、淋巴结转移及TNM分期显著相关,p27kip1蛋白在大肠癌组织中低表达,其表达程度与肿瘤的分化程度及淋巴结转移显著相关,提示stathmin及p27kip1蛋白共同参与了大肠癌的发生、发展;stathmin蛋白可作为一种判断大肠癌恶性程度及侵袭转移的生物学指标.     

P21和Cyclin D1mRNA在食管癌的表达及其意义

目的探讨p21和Cyclin D1mRNA在食管癌中的表达及其临床意义。方法应用RT-PCR检测45例食管癌组织及其对应的正常组织中p21和Cyclin D1mRNA的表达水平。结果p21 mRNA在肿瘤组织的表达显著低于正常组织（P〈0．05），p21mRNA表达减弱与食管癌的临床分期、肿瘤的分化程度相关（P〈0．05）；Cyclin D1mRNA在肿瘤组织的表达显著高于正常组织（P〈0．05），Cyclin D1mRNA表达增强与食管癌的临床分期、肿瘤的分化程度相关（P〈0．05）；在食管癌组织中，p21 mRNA表达与Cyclin D1mRNA呈负相关（r=-0．757，P〈0．05）。结论p21 mRNA的表达下调、Cyclin D1mRNA参与食管癌的发生、发展。     

人子宫内膜癌中p57 kip2、Cyclin D1的表达及意义

目的：探讨p57 kip2、Cyclin D1在人子宫内膜癌发生、发展中的作用。方法选取子宫内膜样腺癌( endometrioid adenocar-cinoma, EA)100例、子宫内膜上皮内瘤变(endometrial intraepithelial neoplasia, EIN)20例、子宫内膜增生性病变20例、增生期子宫内膜组织20例;选取不同子宫内膜细胞[高分化子宫内膜癌细胞( Ishikawa)、中分化子宫内膜癌细胞( JEC)、低分化子宫内膜癌细胞(KLE)及正常子宫内膜细胞(ESC)]进行细胞培养。应用免疫组化EliVision法检测不同子宫内膜组织中p57kip2、Cyclin D1蛋白的表达;Western blot法检测不同子宫内膜细胞中p57 kip2、Cyclin D1蛋白的表达。结果 p57 kip2蛋白在EIN组织中表达最高,在增生期子宫内膜、EA、子宫内膜增生性病变组织中表达逐渐降低,子宫内膜增生性病变与EIN组织中p57 kip2蛋白表达差异有统计学意义(P<0.05)。 Cyclin D1蛋白在EA组织中表达最高,在增生期子宫内膜组织中表达最低,在子宫内膜增生性病变组织、EIN组织中表达依次增高,差异均有显著性( P<0.01)。 p57 kip2、Cyclin D1蛋白在EA组织中的表达随着组织学分级的增高呈依次递减趋势,但仅p57 kip2蛋白表达和组织学分级有关( P<0.05)。 p57 kip2蛋白在KLE中表达最高,在ESC中表达最低,两组相比差异有显著性( P<0.05);Cyclin D1在JEC、Ishikawa中的表达高于ESC,差异均有显著性( P<0.05)。结论 p57kip2、Cyclin D1均参与子宫内膜癌的发生、发展。 Cyclin D1表达是子宫内膜癌发生的早期事件,可能还存在异常合成的p57 kip2蛋白,其协同Cyclin D1促进子宫内膜的恶性转化。联合检测p57 kip2、Cyclin D1在子宫内膜癌中的表达,对预测子宫内膜癌患者预后有一定的临床意义。     

Overexpressions of Cyclin B1, cdc2, p16 and p53 in human breast cancer: the clinicopathologic correlations and prognostic implications

Purpose

The molecular mechanisms that are responsible for the initiation and progression of breast cancers are largely unknown. This study was to analyze the cyclin B1, cdc2, p53 and p16 tumor suppressor genes in human breast cancer.

Materials and Methods

To investigate the role of cyclin B1, cdc2, p53 and p16 in the pathogenesis and progression of breast carcinomas, 98 cases of breast cancers were examined by immunohistochemical method. The correlations of cyclin B1, cdc2, p53 and p16 expression with various clinico-pathologic findings were analysed.

Results

In the normal breast tissues, cyclin B1, cdc2 and p16 were weakly expressed, while p53 was not expressed. On the other hand, cyclin B1, cdc2, p53 and p16 were overexpressed in breast cancer, showing correlation between the expression of cyclin B1 and cdc2 and breast cancers (p=0.00). The overexpressions of cdc2 and p16 were correlated with an infiltrative tumor border pattern and this was statistically significant (p<0.05). In addition, the overexpression of cdc2 was correlated with histologic high grade carcinomas (p=0.00).

Conclusion

Cyclin B1 and cdc2 appeared to be involved in the genesis or progression of breast cancers. In addition, the overexpressions of p16 and p53 may play important roles in more aggressive tumor and the overexpression of cdc2 is associated with progression of tumor to a higher grade of breast carcinomas. The deranged overexpressions of cyclin B1, cdc2, p16 and p53 may play an important role in human breast carcinogenesis.     

Reduced expression of p16 and p27 is correlated with tumour progression in cutaneous melanoma

AIMS: To determine if the cyclin dependent kinase inhibitors (CDKIs) p16 and p27 show reduced expression in the progression from benign to malignant melanocytic tumours, and to correlate these findings with patient prognosis. METHODS: Ninety-two melanocytic tumours were assessed for immunohistochemical expression of p16 and p27. These specimens included nine compound naevi, 10 dysplastic naevi, 17 thin (<1 mm) melanomas, 22 thick (>1 mm) melanomas, nine in-transit metastases, 13 lymph node metastases, and 12 soft tissue metastases. Clinicopathological information on the 39 patients with melanoma primaries was obtained from the Sydney Melanoma Unit database. The median follow up period was 43.3 months. RESULTS: A significant loss of expression of p16 and p27 was found with tumour progression. Positive expression of p27 was found in all compound and dysplastic naevi but only 43.6% of melanoma primaries. Expression of p27 was greater in lymph node and in-transit metastases (63.6%), but lower in soft tissue metastases (36.4%). Positive expression of nuclear p16 was evident in 73.7% of benign naevi, 28.2% of primary melanomas and 14.7% of metastatic melanomas. Neither p16 nor p27 expression was significantly correlated with overall survival, disease free survival or other clinicopathological markers. CONCLUSIONS: The CDKIs p16 and p27 are associated with tumour progression in melanoma, but do not reliably predict recurrence or survival.     

Prognostic implications of cyclin B1, p34cdc2, p27(Kip1) and p53 expression in gastric cancer

PURPOSE: Cell cycle progression is regulated by interactions of specific cyclins and cyclin dependent kinases (CDKs) at the G1-S and G2-M checkpoints and cell cycle deregulation plays a major role in carcinogenesis of human cancers. PATIENTS AND METHODS: To investigate the role of cell cycle regulators in the pathogenesis and progression of human gastric cancers, 23 cases of gastric carcinomas were examined for the expression of cyclin B1, p34cdc2, p27(Kip1) and p53 by immunohistochemical methods, and gene expression was correlated with various clinicopathologic findings. RESULTS: Out of 23 cases studied, cyclin B1 was diffusely expressed in 20 cases (87.0%), p34cdc2 in 14 cases (60.9%) and p53 in 12 cases (52.2%), whereas in normal gastric tissues, cyclin B1 and p34cdc2 were weakly expressed and p53 was not expressed. In contrast, p27(Kip1) was expressed in only 8.7% of gastric carcinomas compared with 78.3% of normal gastric tissues. There was correlation between the expression of cyclin B1 and expression of p34cdc2 (p=0.002), between the expression of cyclin B1 and loss of p27(Kip1) (p=0.025), and between the expression of p34cdc2 and loss of p27(Kip1) (p=0.065). In addition, expression of cyclin B1 was correlated with regional lymph node metastasis (p=0.032). CONCLUSION: Our results indicate that cyclin B1 and p34cdc2 are involved in the genesis or progression of gastric cancers. Furthermore, overexpression of cyclin B1 may play an important role in lymph node metastatic potential of gastric cancer. Thus, abnormal expression of cyclin B1 and CDKs, overexpression of p53 and loss of p27(Kip1) expression may play important roles in human gastric carcinogenesis.     

Expression of p21Waf1, p27Kip1 and cyclin D1 proteins in breast ductal carcinoma in situ: Relation with clinicopathologic characteristics and with p53 expression and estrogen receptor status

p21Waf1 (p21), p27Kip1 (p27) and cyclin D1 have recently been reported as useful prognostic markers for patients with breast carcinoma. However, studies on these cell cycle regulators in ductal carcinoma in situ (DCIS) have been extremely limited. Therefore, we studied the immunohistochemical expression of p21, p27 and cyclin D1 proteins in 49 DCIS cases and compared the findings with the clinicopathologic parameters (age, tumor size, gross type, histologic type, histologic grade, necrosis and mitotic index), p53 and estrogen receptor (ER) status. A significant correlation was found between positive p21 immunoreactivity (67.3% of the cases) and well-differentiated histologic grade, non-comedo type, ER-positive and p53-negative (p53-) status. DCIS with p21+/p53- is likely to be the non-comedo type. The overexpression of cyclin D1 (59.2% of the cases) correlated positively with the ER expression (P = 0.001). The p27 protein expression (46.9% of the cases) correlated with the cyclin D1 immunopositivity (P = 0.0003) and ER expression (P = 0.005). No significant associations were seen in the p27 or cyclin D1 expression and other clinicopathologic parameters. Our results suggest that p21 might be more related to the useful biologic markers in DCIS than p27 or cyclin D1. The significant positive association between p21, p27 or cyclin D1 and ER status, and close association of p27 and cyclin D1 expression might be implicated in the tumor biology of DCIS.     

Immunohistochemical analysis of thymidylate synthase, p16(INK4a), cyclin-dependent kinase 4 and cyclin D1 in colorectal cancers receiving preoperative chemotherapy: significance of p16(INK4a)-mediated cellular arrest as an indicator of chemosensitivity to 5-fluorouracil

High expression of thymidylate synthase (TS) is allegedly associated with the chemoresistance to 5-fluorouracil (5-FU) in colorectal cancers. However, low TS expression does not necessarily imply chemosensitivity. Inactivation of p16(INK4a) correlates with poor prognosis in various cancers. We immunohistochemically evaluated the relationship between the expression of TS, p16(INK4a), CDK4 and cyclin D1 and the effect of 5-FU-based chemotherapy in colorectal cancers. After antigen retrieval, immunoperoxidase staining was performed on the paraffin-embedded, biopsy and surgical specimens of 37 advanced colorectal cancers preoperatively treated with peroral administration of 5-FU derivatives. As a control group, 31 colorectal cancers without preoperative treatment were analyzed. High TS expression was found in 23 (74%) of 31 tumors resected from histological non-responders and in 19 (61%) of 31 controls but in none of six responders. High p16(INK4a) expression was seen in 83% of the responders, 52% of the non-responders and 32% of the controls. The TS-low/p16(INK4a)-high phenotype was noted in 83% of the responders, but only in 3% of the non-responders (P = 0.0001). Induction of p16(INK4a) expression after chemotherapy was predominantly seen in the responders. Neither CDK4 nor cyclin D1 expression was related to the chemotherapeutic effects. In conclusion, the combination of low expression of TS and induction of p16(INK4a) after chemotherapy can be important indicators of the sensitivity to 5-FU-based chemotherapy in colorectal cancers.     

Increased cyclin D3 expression significantly correlates with p27 nuclear positivity in gastrointestinal stromal tumors

Gastrointestinal stromal tumors, the most common mesenchymal tumors of the gastrointestinal tract, are characterized by strong expression of c-Kit protein. Recently, it has been shown that gastrointestinal stromal tumors may also contain alterations of genes involved in the regulation of cell cycle. In this study, we evaluate the prevalence and clinical significance of cyclin D1 and D3, Ki-67, p27, and retinoblastoma protein expression in a group of 50 human gastrointestinal stromal tumors selected from the files of the Moffitt Cancer Center. Tissue sections from each case were subjected to immunostaining using the avidin-biotin complex method. Cyclin D1 nuclear positivity was detected in 21 of 50 (42%) and cyclin D3 in 24 of 50 (48%) cases. p27 high immunoreactivity and negative or decreased retinoblastoma protein expression were identified in 33 of 50 (66%) gastrointestinal stromal tumors. In 19 of 50 (38%) tumors, Ki-67 had high labeling index. Direct correlation was observed between cyclin D3 and p27 expression (P < .0001), and between cyclin D1 and retinoblastoma protein (P = .03). Coexpression of cyclin D3 and p27 was demonstrated by immunofluorescence. The p27 protein expression inversely correlated with tumor size (P = .004), but was not correlated with tumor grade (P = .12). Ki-67 directly correlated with both tumor size (P = .03) and tumor grade (P = .008). We report a direct correlation between cyclin D3 and p27 expression in gastrointestinal stromal tumors. Additional alterations in cyclin D1, Ki-67, and retinoblastoma protein expression indicate a disregulated cell cycle in these tumors.     

细胞周期抑制蛋白p16、p27蛋白表达与垂体腺瘤侵袭性的关系

目的探讨p27、p16、PCNA的蛋白表达与垂体腺瘤侵袭性的关系,为根治垂体腺瘤及减少肿瘤术后复发提供实验依据。方法应用免疫组化SP法检测43例侵袭性垂体腺瘤和37例非侵袭性腺瘤的p16、p27和PCNA蛋白表达水平,分析p16、p27蛋白表达水平与PCNA蛋白表达之间的相关性。结果垂体侵袭腺瘤p16、p27蛋白表达较非侵袭组明显减低;复发组p16蛋白表达的阳性率与非复发组之间无统计学意义。p27蛋白表达的阳性率较非复发组减低有显著差异。结论p16、p27蛋白表达异常与垂体腺瘤的发生及侵袭性有关,它们的表达情况能作为垂体腺瘤侵袭性的参考指标。     

p16INK4A overexpression and HPV infection in uterine cervix adenocarcinoma

Human papillomaviruses (HPVs) are causally involved in the genesis of cervical carcinomas and their precursors, and there is a strong relationship between the cyclin-dependant kinase inhibitor p16^INK4A and HPV infection. This study was carried out to assess the correlations between p16^INK4A expression as an early biomarker of the endocervical adenocarcinoma and HPV infection. p16^INK4A expression and HPV typing were performed on 46 samples including 5 normal endocervix, 9 benign lesions of the endocervix, 25 endocervical adenocarcinomas, and 7 endometrioid adenocarcinomas of the uterine corpus. A semiquantification of the p16^INK4A immunostaining was realized (using both the staining intensity and the percentage of positive cells) and was graded from 0 to 15. All of the 25 endocervical adenocarcinomas overexpressed p16^INK4A; the adjacent epithelium and the connective tissue were strictly negative. No p16^INK4A was detected in nine benign endocervical lesions and in five normal endocervix. Few endometrioid adenocarcinomas of the uterine corpus that infiltrate the endocervix exhibited a low immunoreactivity (score 0/15 or 1/15). This pattern of expression is significantly associated with HPV infection (p<10 ⁻³), mainly high-risk HPV types (p=0.02). Our results suggest that p16^INK4A is a putative molecular biomarker that consistently discriminates uterine cervix adenocarcinomas from benign lesions and from endometrioid adenocarcinomas of the uterine corpus .     

Differential expression of cdk inhibitors p16, p21cip1, p27kip1, and cyclin E in cervical cytological smears prepared by the ThinPrep method

Our objective was to correlate p16, p21cip1, p27kip1, and cyclin E protein expression with the degree of dysplasia on ThinPrep Papanicolaou (Pap) smears using a modified immunoperoxidase staining. Smears read as normal, atypical squamous cells of undetermined significance (ASC-US), low-grade squamous intraepithelial lesion (LSIL), or high-grade SIL (HSIL) were identified and tested for high-risk human papillomavirus (HR-HPV). Additional smears were processed for immunoperoxidase for p16, p21cip1, p27kip1, and cyclin E. Thirty-four smears were satisfactory for study. The p16 was positive in all nine HSIL, in four of nine LSIL, and in one of seven ASC-US. The p27kip1 was positive in all nine HSIL, in eight of nine LSIL, and in one of seven ASC-US. The p21cip1 was positive in all nine HSIL, in one of nine LSIL, and in one of seven ASC-US. Cyclin E was positive in seven of nine HSIL and in one of nine LSIL and in none of the ASC-US smears. Normal smears were negative for all the antigens. There was poor correlation of protein expression and HR-HPV infection. We concluded that p16, p21cip1, p27kip1, and cyclin E can be demonstrated on Pap smears and they are expressed differentially in dysplastic cells, with highest expression in HSIL. The p21cip1 and cyclin E showed the greatest correlation with HSIL.     

胃肠道类癌中p27kip1、PCNA表达及p16基因缺失

目的 :探讨 p2 7kip1 、PCNA及 p1 6与胃肠道类癌转移的关系。 方法 :采用免疫组化SABC法检测 2 5例胃肠道类癌组织中p2 7kip1 和PCNA蛋白表达 ,同时用PCR法检测 p1 6基因的缺失情况。 结果 :p2 7kip1 在胃肠道类癌阳性表达率为 64 % (1 6/ 2 5) ,PCNAⅠ～Ⅱ级和Ⅲ～Ⅳ级表达率分别为 56 %、44 %。 2种蛋白阳性表达率与分化程度无相关性 (P >0 0 5) ,与淋巴结转移相关 (P <0 0 5)。p2 7kip1 与PCNA表达负相关。p1 6基因纯合性缺失率为 48% (1 2 / 2 5) ,其缺失率与类癌分化程度和淋巴结转移无关。结论 :p2 7kip1 低表达、PCNA高表达与胃肠道类癌转移有关 ,胃肠道 ;类癌的发生与p1 6基因缺失有关 ,但可能为早期分子事件。     

Alterations of expression of Rb,p16INK4A and cyclin D1 in non-small cell lung carcinoma and their clinical significance

Inactivation of the Rb pathway in non-small cell lung carcinoma (NSCLC) occurs mostly through inactivation of the cyclin-dependent kinase inhibitor p16^INK4A and/or up-regulation of cyclin D1. In order to assess the frequency and the prognostic value of these abnormalities in NSCLC, immunohistochemical analysis of Rb, p16^INK4, and cyclin D1 has been performed on 168 cases of NSCLC including 77 squamous cell carcinomas, 43 adenocarcinomas, and 48 basaloid carcinomas. The reduced survival rate of basaloid carcinoma (stage I–II) compared with other histological types of NSCLC was confirmed (p = 0·008). Loss of protein expression of Rb and p16^INK4A was observed in 12 per cent and 58 per cent of NSCLC cases respectively and cyclin D1 overexpression in 43 per cent. There was an inverse correlation between Rb and p16 expression ( p < 0·0001) and a direct correlation between Rb and cyclin D1 expression ( p = 0·0007). In univariate analysis, Rb-negative adenocarcinomas at stages I–II had a significantly shorter survival than Rb-positive cases ( p = 0·04) and stages I–II p16-positive cases had a shorter survival than p16-negative cases ( p = 0·02), which was more significant in basaloid carcinoma ( p = 0·003). p16 status retained its influence on survival in multivariate analysis at stage I–II for all cases ( p = 0·01) and for basaloid carcinoma ( p = 0·005). Cyclin D1 overexpression did not influence survival. Combined Rb/p16/cyclin D1 phenotypes in univariate analysis showed a shorter survival for Rb-negative/p16-positive/cyclin D1-negative tumours ( p = 0·002). These results, linked to previous data, indicate that the Rb pathway of G1 arrest is initially disrupted in the vast majority of NSCLCs (83 per cent), but could not confirm an unfavourable role for each individual event (p16^INK4A loss or cyclin D1 up-regulation) in prognosis. Copyright © 1999 John Wiley & Sons, Ltd.     

p16 expression in colorectal adenocarcinoma: marker of aggressiveness and morphological types

Aim: The aim of the present study was to investigate the clinicopathological roles of p16 expression in a large cohort of patients with colorectal adenocarcinoma with tight methodology and close follow-up. Methods: p16 protein expression was investigated in 194 patients (102 men, 92 women) with colorectal adenocarcinomas by immunohistochemistry. The findings were correlated with their clinicopathological features. Results: p16 protein was detected in 80% (155 of 194) of patients with colorectal carcinoma. The p16 protein was more often detected in male patients with colorectal cancers (86% versus 73%, p = 0.03). p16 protein expression was more often seen in carcinomas in the rectum, sigmoid and descending colon compared with more proximal colon (90% versus 61%, p = 0.001). The p16 protein was more often detected in well or moderately differentiated colorectal adenocarcinoma than poorly differentiated colorectal adenocarcinoma (84% versus 63%, p = 0.009). The level of expression of p16 protein is related to the lymph nodal status (p = 0.004) and the TNM staging of the colorectal carcinoma (p = 0.008). Conclusion: p16 protein expression was common in colorectal adenocarcinomas. The expression correlated with gender of the patient, distal location, differentiation and staging of the tumour. The findings suggest that p16 plays an important role in cancer pathogenesis and has implications for improving the clinical management.     

Reduced expression of the RNA‐binding protein HuD in pancreatic neuroendocrine tumors correlates with low p27Kip1 levels and poor prognosis

For the majority of patients diagnosed with pancreatic neuroendocrine tumors (NETs), there is significant malignant potential with a poor prognosis; however, the molecular abnormalities and pathogenesis of pancreatic NETs have not been firmly established. Here, we report that loss of expression of the RNA‐binding protein HuD correlates with low p27^Kip1 (p27) levels and poor prognosis in pancreatic NETs. HuD expression was frequently lost in many human pancreatic NETs, and these pancreatic NETs showed aggressive clinicopathological phenotypes with low p27 levels, increased tumor size, higher World Health Organization grade and pT stage of the tumor, and the presence of angioinvasion. Furthermore, loss of HuD was an independent, progression‐free prognostic factor in multivariate survival analysis. However, the level of HuR, a member of the same Hu protein family as HuD, was not significantly correlated with pancreatic NET size and progression. Mechanistically, HuD enhanced p27 mRNA translation by interacting with both the 5′‐untranslated region (UTR) and the 3′‐UTR of p27 mRNA, and consequently suppressed cell cycle progression and tumor growth. In addition, HuD competed with miR‐30a‐3p for binding to the 3′‐UTR of p27 mRNA, suggesting an interplay between HuD and miR‐30a‐3p in controlling p27 translation. Our results identify HuD as a pivotal suppressor of pancreatic NET growth, and suggest that HuD has potential value as a prognostic factor of pancreatic NETs. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.