Differential expression of keratins 10, 17, and 19 in normal cervical epithelium, cervical intraepithelial neoplasia, and cervical carcinoma

Use of Cytokeratin 17 in the Differentiation Between Desmoplastic Trichilemmoma and Cutaneous Basal Cell Carcinoma

ABSTRACT

Desmoplastic trichilemmoma (DTL) is a variant of trichilemmoma characterized by a prominent desmoplastic stroma that may mimic invasive carcinoma. These lesions typically show features of a conventional trichilemmoma at the periphery, surrounding dense hyalinized stroma with entrapped cords of tumor cells. On a small or superficial biopsy, DTL may pose a diagnostic challenge in distinguishing this benign adnexal neoplasm from invasive carcinoma, particularly basal cell carcinoma (BCC). We aimed to investigate whether the immunohistochemical expression of cytokeratin 17 (CK17) would be useful in the differentiation between DTL and BCC. CK17 is expressed in normal adnexal structures and has been shown to demonstrate strong staining in BCCs. Expression of CK17 was examined in 23 cases of DTL and 23 BCCs. An immunoreactivity score was assigned using the percentage of tumor cells staining with scoring as follows: 0, complete negativity; 1, < 15% tumor cells staining; 2, 15%-84% tumor cells staining; and 3, >85% staining. All cases of BCC scored as 3, whereas 18% of DTL scored as 3. The mean percent staining for CK17 was significantly higher for BCCs (97% of tumor cells) than DTLs (57% of tumor cells); P < 0.001 in the unpaired t test. The pattern of CK17 staining may also help differentiate between cases scoring 3. All BCCs showed strong diffuse staining throughout, whereas for those cases of DTL with a score of 3, the peripheral basaloid rim in the tumor lobules did not stain. CK17 is a useful adjunct in distinguishing DTL from BCC in small or superficial biopsy specimens.

The cytokeratin 17 expression in primary ovarian tumors has diagnostic but not prognostic significance

We assessed the value of cytokeratin 17 (CK17) expression for the differential diagnosis between primary ovarian mucinous tumors and metastases from the gastrointestinal tract (GIT) and the significance of CK17 expression in a broad spectrum of primary ovarian tumors with respect to their prognosis. The sample set consisted of 554 primary ovarian tumors and 255 GIT tumors. In the primary ovarian tumors, a higher CK17 expression (in > 10% of tumors cells) was present only in 0-11.4% of all tumors (including mucinous tumors, micropapillary serous borderline tumors, clear cell, endometrioid, and high-grade serous carcinomas). The only exception was low-grade serous carcinoma, where higher CK17 expression was present in 24% of cases. Concerning GIT tumors, the higher levels of CK 17 expression (in > 10% of tumor cells) were observed in the upper GIT tumors (68.5% of pancreatic ductal adenocarcinoma, 61.6% of gallbladder adenocarcinoma, and 46% of gastric adenocarcinoma), which differs substantially not only from most of the primary ovarian tumors, but also from colorectal carcinoma (3.7%; p < 0.001). The results of our study suggest that expression of CK17 can potentially be used as an adjunct marker in differential diagnosis between primary ovarian mucinous tumors and metastases from the upper GIT, but not from colorectal carcinoma. However, in GIT tumors, CK17 can be used in the differential diagnosis between adenocarcinomas of the upper and lower GIT. Statistical analysis did not reveal strong association of CK17 expression with clinicopathological variables or patient outcomes in any primary ovarian tumors.

E6/E7 Functional Differences among Two Natural Human Papillomavirus 18 Variants in Human Keratinocytes

It is suggested that HPV-18 variants from the A lineage have higher oncogenic potential compared to B variants. Some studies show uneven distribution of HPV-18 variants in cervical adenocarcinomas and squamous cell carcinomas. Regarding HPV-18 variants’ functions, the few studies reported focus on E6, and none were performed using natural host cells. Here, we immortalized primary human keratinocytes (PHKs) with E6/E7 of HPV-18 A1 and B1 sublineages and functionally characterized these cells. PHK18A1 reached immortalization significantly faster than PHK18B1 and formed a higher number of colonies in monolayer and 3D cultures. Moreover, PHK18A1 showed greater invasion ability and higher resistance to apoptosis induced by actinomycin-D. Nevertheless, no differences were observed regarding morphology, proliferation after immortalization, migration, or epithelial development in raft cultures. Noteworthy, our study highlights qualitative differences among HPV-18 A1 and B1 immortalized PHKs: in contrast to PHK18A1, which formed more compact colonies and spheroids of firmly grouped cells and tended to invade and migrate as clustered cells, morphologically, PHK18B1 colonies and spheroids were looser, and migration and invasion of single cells were observed. Although these observations may be relevant for the association of these variants with cervical cancer of different histological subtypes, further studies are warranted to elucidate the mechanisms behind these findings.

Cervical Adenoid Basal Carcinoma: Clinicopathologic Features of 9 Cases With Reference to CK17 and Ki-67 Expression

OBJECTIVE

The aims of this study were to clarify the histological features of adenoid basal carcinoma (ABC) and determine whether cytokeratin 17 (CK17) and Ki-67 can facilitate the differential diagnosis of ABC from squamous cell carcinoma (SCC).

MATERIALS AND METHODS

Nine cases of pure ABC were collected from the files of the Division of Pathology at the Zhejiang University Hospital Women's School of Medicine. For comparison, 20 cases of moderately to poorly differentiated cervical SCC, including 2 of basaloid SCC, were also retrieved from the same period. Blocks were recut, reread, and immunostained for CK17 and Ki-67.

RESULTS

Morphologically, ABCs were mainly composed of small basaloid cell nests and variable squamous differentiation foci. For immunohistochemical staining, 1 of 9 cases showed diffuse CK17 staining, 5 of 9 showed focal positive staining, and 3 of 9 showed negative staining in the basaloid cell area of ABC, whereas no CK17 expression was found in ABC squamous foci. Eighteen of the 20 invasive SCCs showed diffuse CK17 staining, and 2 showed focal staining. The Ki-67 proliferative index varied in different ABC areas, with a relatively high index in squamous differentiation foci and a low index in basaloid cell areas. In contrast, Ki-67 staining was unevenly intense in SCC.

CONCLUSIONS

Adenoid basal carcinoma had characteristic morphological features, and the differential diagnosis of ABC from SCC is usually simple, based on morphology. In select cases, when histological findings are equivocal, the loss of CK17 expression in the squamous differentiation area, and a lower Ki-67 index in basal cell foci support ABC diagnosis.

Assessment of CK17 as a Marker for the Diagnosis of Differentiated Vulvar Intraepithelial Neoplasia

Differentiated vulvar intraepithelial neoplasia (dVIN), precursor of vulvar squamous cell carcinoma, is human papilloma virus independent and often found in a background of lichen sclerosus (LS) and lichen simplex chronicus (LSC). Subtle histologic findings make the diagnosis of dVIN difficult, and, although the use of p53 and Ki-67 has been of some value, there is a need for a better immunohistochemical marker. Cytokeratin 17 (CK17), a cytoskeletal intermediate filament protein, has previously been used in the diagnosis of anogenital lesions. Here we evaluated CK17 in dVIN in comparison with LS, LSC, and usual VIN (uVIN/HSIL). Twenty-nine cases of dVIN, 9 cases of uVIN, 8 cases of LS, and 7 of LSC were evaluated using CK17, Ki-67, and p53. All 29 dVIN cases displayed immunoreactivity for CK17, with 27 (93%) showing intermediate to strong and diffuse reactivity. No cases of uVIN displayed diffuse CK17 expression, whereas 63% of LS and 29% of LSC displayed intermediate to strong diffuse immunoreactivity, confined to the upper half of the epithelium. P53 and Ki-67 expression was present in varying degrees in all types of lesions, displaying limited discriminatory power for dVIN. Our findings suggest that CK17, although not specific for dVIN, when combined with histologic findings, Ki-67, and p53 immunohistochemistry, can be a marker of vulvar dysplasia and serve as an adjunct in the diagnosis of dVIN. Specifically, in small biopsies, the presence of diffuse suprabasal or full thickness expression strongly favors a diagnosis of dVIN over LSC, whereas focal and/or superficial expression supports a diagnosis of LSC.

TGF-β1-induced CK17 enhances cancer stem cell-like properties rather than EMT in promoting cervical cancer metastasis via the ERK1/2-MZF1 signaling pathway

Tumor metastasis remains a major obstacle for improving overall cancer survival in cervical cancer (CC), which may be due to the existence of tumor microenvironment-related cancer stem cells (CSCs) and epithelial-mesenchymal transition (EMT). The mechanism underlying these processes needs to be further elucidated. Here, we report that TGF-β1, one of the key microenvironmental stimuli, can enhance CSC characteristics, facilitate the EMT, and induce CK17. Silencing CK17 expression attenuated CSC-like properties without affecting the EMT markers induced by TGF-β1, whereas forced overexpression of CK17 promoted lymphatic metastasis in vivo even without EMT inducement. Inhibitors of ERK1/2 signaling drastically decreased the induction of CK17 mediated by TGF-β1. By combined computational and experimental approaches, we identified and validated that MZF1 was a key transcription factor binding to the promoter of CK17. Taken together, these results demonstrate that CK17 induced by the TGF-β1-ERK1/2-MZF1 signaling pathway facilitates metastasis by promoting the acquisition of CSC properties rather than by inducing the EMT process in CC, suggesting that this CK17-related signaling pathway might be a suitable target for the development of therapy for CC metastasis.

Correlation of P16 (Ink4a) and CK17 to HPV (16E6+18E6) in Premalignant and Malignant Lesions of Uterine Cervix: A Clinicopathologic Study

BACKGROUND

This research was accomplished to evaluate the IHC expression of p16 (ink4a) and CK17 in low grade cervical intraepithelial lesions (LSIL), high grade cervical intraepithelial lesions (HSIL) and invasive cervical carcinomas and to assess their correlation to HPV (16E6+18E6).

METHODS

The study included (127) formalin-fixed paraffin-embedded cervical biopsies; of which 22 cases were chronic cervicitis, 24 cases were LSIL, 28 cases were HSIL and 53 cases were invasive cervical carcinomas. Sections were immunohistochemically stained for p16 (ink4a), CK17 and HPV (16E6+18E6).

RESULTS

The study established a highly significant increase in IHC of expression of p16 (ink4a), CK17 and HPV (16E6+18E6) from LSIL through HSIL to invasive carcinomas (P-value˂0.001). There was non-significant association between IHC expression of all makers with age of patients; types, grade and stage of cervical carcinomas (P-value˃0.05). HPV (16E6+18E6) revealed a significantly positive correlation with p16 (ink4a) (P-value˂0.05) and a non- significant correlation with CK17 (P-value˃0.05); in LSIL, HSIL and invasive carcinoma cases.

CONCLUSION

p16 (ink4a) expression directly reflects infection with high risk HPV in cervical lesions and can add a significant diagnostic accuracy in the evaluation of CIN. CK 17 is a good marker of malignant transformation, with increasing in its expression according to the severity of cervical lesions; however, it is not related to HPV infection. Both markers are not related to prognostic variables of patients with cervical carcinoma.

Gene expression of cytokeratin 19 and its molecular detection in human breast cancer cell lines

Cytokeratins have been identified as useful tools in oncology diagnostics. In this study, cytokeratin19 (CK19) expression was studied in three human breast cancer cell lines, SKBR3, BT549, and BT474 using RT-PCR. CK19 was expressed in tumor cell of different origin, showing higher expression in invasive breast cancer with ER(+) (BT474) than invasive breast cancer with ER(-) (BT549) and breast adenocarcinoma with ER(-) (SKBR3). Two primer sets were used to evaluate CK19 expression. Primer set I (hCK19/1) and primer set II (hCK19/2) were used to amplify the CK19 human gene at a 215bp and 384bp, respectively, whereas PBMC and RAW264.7 (mouse macrophage) no detectable PCR products were obtained. The sensitivity for detection was determined by two methods, i.e., cDNA dilution (the dilution of cDNA from RNA of breast cancer cells) and cell dilution (the dilution of breast cancer cells in PBMC). hCK19/2 was more sensitive than hCK19/1. In cDNA dilution, the lower limits of primer set II for detection were 400, 40 and 40 cells for SKBR3, BT549 and BT474 cells, respectively. While in cell dilution all of the 3 breast cancer cells could be detected at 1 cancer cell in 10(4), 10(6) and 10(5) PBMC, respectively. The data supported the possibility that CK19 could be detected and be the marker for breast cancer in patient blood.

Keratin 17 in premalignant and malignant squamous lesions of the cervix: proteomic discovery and immunohistochemical validation as a diagnostic and prognostic biomarker

Most previously described immunohistochemical markers of cervical high-grade squamous intraepithelial lesion (HSIL) and squamous cell carcinoma may help to improve diagnostic accuracy but have a minimal prognostic value. The goals of the current study were to identify and validate novel candidate biomarkers that could potentially improve diagnostic and prognostic accuracy for cervical HSIL and squamous cell carcinoma. Microdissected tissue sections from formalin-fixed paraffin-embedded normal ectocervical squamous mucosa, low-grade squamous intraepithelial lesion (LSIL), HSIL and squamous cell carcinoma sections were analyzed by mass spectrometry-based shotgun proteomics for biomarker discovery. The diagnostic specificity of candidate biomarkers was subsequently evaluated by immunohistochemical analysis of tissue microarrays. Among 1750 proteins identified by proteomic analyses, keratin 4 (KRT4) and keratin 17 (KRT17) showed reciprocal patterns of expression in the spectrum of cases ranging from normal ectocervical squamous mucosa to squamous cell carcinoma. Immunohistochemical studies confirmed that KRT4 expression was significantly decreased in squamous cell carcinoma compared with the other diagnostic categories. By contrast, KRT17 expression was significantly increased in HSIL and squamous cell carcinoma compared with normal ectocervical squamous mucosa and LSIL. KRT17 was also highly expressed in immature squamous metaplasia and in endocervical reserve cells but was generally not detected in mature squamous metaplasia. Furthermore, high levels of KRT17 expression were significantly associated with poor survival of squamous cell carcinoma patients (Hazard ratio=14.76, P=0.01). In summary, both KRT4 and KRT17 expressions are related to the histopathology of the cervical squamous mucosa; KRT17 is highly overexpressed in immature squamous metaplasia, in HSIL, and in squamous cell carcinoma and the level of KRT17 in squamous cell carcinoma may help to identify patients who are at greatest risk for cervical cancer mortality.

Adenoid squamous cell carcinoma of the oral cavity

Because immunohistochemical features of adenoid squamous cell carcinoma (AdSCC) of the oral cavity is unclear, the author reports herein AdSCC in the gingival with an emphasis on immunohistochemical features. A 73-year-old woman presented with a left lower gingival tumor. The tumor was mildly elevated tumor measuring 1.5 x 1.5 x 0.5 cm. Dentist's diagnosis was granulation tissue, and a biopsy was taken. The biopsy showed proliferation of carcinoma cells arranged in cords, and squamous and tubular differentiations were noted in places. The biopsy diagnosis was adenosquamous carcinoma. Tumor excision with resection of mandibular bone was performed. The resected tissue showed a mixture and squamous cell carcinoma and tubular formation. Gradual merges between the two and acantholytic features of the squamous cell carcinoma element were seen. Both components were free from mucins. Both components were positive for pancytokeratins (AE1/3, CAM5.2) +++, cytokeratin (CK) 5/6 +, CK34βE12 ++, CK7 +, CK14 +++, CEA +, CA19-9 +, CA125 +, p53 +++, p63 +++, KIT + and MUC1 ++. Both components were negative for CK8, CK18, CK19, CK20, EMA, vimentin, TTF-1, desmin, myoglobin, S100 protein, melanosome, smooth muscle actin, CD34, CDX2, CD10, chromogranin, synaptophysin, NSE, CD56, lysozyme, CD68, MDM2, PDGFRA, MUC2, MUC5AC, and MUC6. Since both components were positive for squmaous cell carcinoma markers (CD5/6, CK34βE12, and p63) and adenocarcinoma markers (CEA, CA19-9, CA125, MUC1), this case of AdSCC appears an intermediate form between adenocarcinoma and squamous cell carcinoma. The margins were negative. No metastasis was found by imaging techniques. The patient is now free from tumor and is followed up carefully.

A systematic analysis on DNA methylation and the expression of both mRNA and microRNA in bladder cancer

BACKGROUND

DNA methylation aberration and microRNA (miRNA) deregulation have been observed in many types of cancers. A systematic study of methylome and transcriptome in bladder urothelial carcinoma has never been reported.

METHODOLOGY/PRINCIPAL FINDINGS

The DNA methylation was profiled by modified methylation-specific digital karyotyping (MMSDK) and the expression of mRNAs and miRNAs was analyzed by digital gene expression (DGE) sequencing in tumors and matched normal adjacent tissues obtained from 9 bladder urothelial carcinoma patients. We found that a set of significantly enriched pathways disrupted in bladder urothelial carcinoma primarily related to "neurogenesis" and "cell differentiation" by integrated analysis of -omics data. Furthermore, we identified an intriguing collection of cancer-related genes that were deregulated at the levels of DNA methylation and mRNA expression, and we validated several of these genes (HIC1, SLIT2, RASAL1, and KRT17) by Bisulfite Sequencing PCR and Reverse Transcription qPCR in a panel of 33 bladder cancer samples.

CONCLUSIONS/SIGNIFICANCE

We characterized the profiles between methylome and transcriptome in bladder urothelial carcinoma, identified a set of significantly enriched key pathways, and screened four aberrantly methylated and expressed genes. Conclusively, our findings shed light on a new avenue for basic bladder cancer research.

Automated biochemical, morphological, and organizational assessment of precancerous changes from endogenous two-photon fluorescence images

Background

Multi-photon fluorescence microscopy techniques allow for non-invasive interrogation of live samples in their native environment. These methods are particularly appealing for identifying pre-cancers because they are sensitive to the early changes that occur on the microscopic scale and can provide additional information not available using conventional screening techniques.

Methodology/Principal Findings

In this study, we developed novel automated approaches, which can be employed for the real-time analysis of two-photon fluorescence images, to non-invasively discriminate between normal and pre-cancerous/HPV-immortalized engineered tissues by concurrently assessing metabolic activity, morphology, organization, and keratin localization. Specifically, we found that the metabolic activity was significantly enhanced and more uniform throughout the depths of the HPV-immortalized epithelia, based on our extraction of the NADH and FAD fluorescence contributions. Furthermore, we were able to separate the keratin contribution from metabolic enzymes to improve the redox estimates and to use the keratin localization as a means to discriminate between tissue types. To assess morphology and organization, Fourier-based, power spectral density (PSD) approaches were employed. The nuclear size distribution throughout the epithelial depths was quantified by evaluating the variance of the corresponding spatial frequencies, which was found to be greater in the normal tissue compared to the HPV-immortalized tissues. The PSD was also used to calculate the Hurst parameter to identify the level of organization in the tissues, assuming a fractal model for the fluorescence intensity fluctuations within a field. We found the range of organization was greater in the normal tissue and closely related to the level of differentiation.

Conclusions/Significance

A wealth of complementary morphological, biochemical and organizational tissue parameters can be extracted from high resolution images that are acquired based entirely on endogenous sources of contrast. They are promising diagnostic parameters for the non-invasive identification of early cancerous changes and could improve significantly diagnosis and treatment for numerous patients.

Identification and validation of genes involved in cervical tumourigenesis

Background

Cervical cancer is the most common cancer among Indian women. This cancer has well defined pre-cancerous stages and evolves over 10-15 years or more. This study was undertaken to identify differentially expressed genes between normal, dysplastic and invasive cervical cancer.

Materials and methods

A total of 28 invasive cervical cancers, 4 CIN3/CIS, 4 CIN1/CIN2 and 5 Normal cervix samples were studied. We have used microarray technique followed by validation of the significant genes by relative quantitation using Taqman Low Density Array Real Time PCR. Immunohistochemistry was used to study the protein expression of MMP3, UBE2C and p16 in normal, dysplasia and cancers of the cervix. The effect of a dominant negative UBE2C on the growth of the SiHa cells was assessed using a MTT assay.

Results

Our study, for the first time, has identified 20 genes to be up-regulated and 14 down-regulated in cervical cancers and 5 up-regulated in CIN3. In addition, 26 genes identified by other studies, as to playing a role in cervical cancer, were also confirmed in our study. UBE2C, CCNB1, CCNB2, PLOD2, NUP210, MELK, CDC20 genes were overexpressed in tumours and in CIN3/CIS relative to both Normal and CIN1/CIN2, suggesting that they could have a role to play in the early phase of tumorigenesis. IL8, INDO, ISG15, ISG20, AGRN, DTXL, MMP1, MMP3, CCL18, TOP2A AND STAT1 were found to be upregulated in tumours. Using Immunohistochemistry, we showed over-expression of MMP3, UBE2C and p16 in cancers compared to normal cervical epithelium and varying grades of dysplasia. A dominant negative UBE2C was found to produce growth inhibition in SiHa cells, which over-expresses UBE2C 4 fold more than HEK293 cells.

Conclusions

Several novel genes were found to be differentially expressed in cervical cancer. MMP3, UBE2C and p16 protein overexpression in cervical cancers was confirmed by immunohistochemistry. These will need to be validated further in a larger series of samples. UBE2C could be evaluated further to assess its potential as a therapeutic target in cervical cancer.

Stromal issues in cervical cancer: a review of the role and function of basement membrane, stroma, immune response and angiogenesis in cervical cancer development

The carcinogenesis of cervical carcinoma implies an intricate interplay of neoplastic, human papillomavirus infected epithelial cells and stromal tissue, in which different factors have distinct but interacting influence. Persistent infection with an oncogenic human papillomavirus type may lead to epithelial dysplasia with progressive severity. To access the adjacent stromal tissue, tumour cells have to breach the basement membrane. The stroma partly controls tumour growth, invasion and angiogenesis. Last but not least there is considerable influence of the immune response. In this review we describe the importance of various stromal factors in carcinogenesis of cervical cancer.

The immortalizing and transforming ability of two common human papillomavirus 16 E6 variants with different prevalences in cervical cancer

Persistent infection with high-risk human papillomaviruses (HPVs), especially type 16 has been undeniably linked to cervical cancer. The Asian-American (AA) variant of HPV16 is more common in the Americas than the prototype in cervical cancer. The different prevalence is based on three amino acid changes within the E6 protein denoted Q14H/H78Y/L83V. To investigate the mechanism(s) behind this observation, both E6 proteins, in the presence of E7, were evaluated for their ability to extend the life span of and transform primary human foreskin keratinocytes (PHFKs). Long-term cell culture studies resulted in death at passage 9 of vector-transduced PHFKs (negative control), but survival of both E6 PHFKs to passage 65 (and beyond). Compared with E6/E7 PHFKs, AA/E7 PHFKs were significantly faster dividing, developed larger cells in monolayer cultures, showed double the epithelial thickness and expressed cytokeratin 10 when grown as organotypic raft cultures. Telomerase activation and p53 inactivation, two hallmarks of immortalization, were not significantly different between the two populations. Both were resistant to anoikis at later passages, but only AA/E7 PHFKs acquired the capacity for in vitro transformation. Proteomic analysis revealed markedly different protein patterns between E6/E7 and AA/E7, particularly with respect to key cellular metabolic enzymes. Our results provide new insights into the reasons underlying the greater prevalence of the AA variant in cervical cancer as evidenced by characteristics associated with higher oncogenic potential.

Keratin expression in endocrine organs and their neoplasms

Keratins are intermediate filaments that provide mechanical support and fulfill a variety of additional functions in epithelial cells. Keratins show outstanding degree of molecular diversity. In humans, 54 functional keratin genes exist. Twenty common types of keratins are expressed in highly specific patterns related to epithelial type and stage of cellular differentiation. In general, keratins are classified as high-molecular-weight keratins (expressed in normal stratified epithelium and tumors derived from it) and low-molecular-weight keratins (expressed in normal simple epithelium and tumors derived from it). Histologically, endocrine organs belong to simple epithelium; thus, endocrine tissues usually express low-molecular-weight keratins. When an endocrine organ undergoes malignant transformation, its keratin profile usually remains constant. However, keratin expression in endocrine organs and endocrine tumors is much more complicated because of their diversified histogenesis. In this review article, we will first briefly review the molecular biology and protein chemistry of the keratins. We will then review the expression patterns of keratins in normal endocrine tissue and endocrine neoplasms.

Coordinate expression of cytokeratin 8 and cytokeratin 17 immunohistochemical staining in cervical intraepithelial neoplasia and cervical squamous cell carcinoma: an immunohistochemical analysis and review of the literature

OBJECTIVE

Several Cytokeratin (CK) isoforms have been analyzed in cervical intraepithelial lesions. However, previously reported numbers of specimens have been too low to evaluate any correlation between CK and CIN.

METHODS

We examined the immunohistochemical staining of p16, CK8, and CK17 in 134 cervical tissues obtained by punch biopsy and graded as follows: CIN I (n=39), CIN II (n=31), CIN III (n=43), SCC (n=21).

RESULTS

p16 staining was identified in 74.4% of CIN I, 93.6% of CIN II, 97.7% of CIN III, and 100% of SCC cases. CK8 and CK17 staining were identified in 12.8% and 33.3% of CIN I, 22.6% and 58.1% of CIN II, 62.8% and 81.4% of CIN III, and 71.4% and 95.2% of SCC cases, respectively. Interestingly, positivity for CK8 and CK17 correlated with increasing lesion grade of the intraepithelial lesions and also correlated with p16 staining (p16, p=0.0008; CK8, p<0.0001, and CK17, p<0.0001), and a coordinate expression profile of CK8[+]/CK17[+] correlates with increasing CIN grade and carcinoma (likewise, a coordinate expression profile of CK8[-]/CK17[-] correlates with decreasing CIN grade and absence of carcinoma), but expression of just CK8 (CK8[+]/CK17[-]) or just CK17 (CK8[-]/CK17[+]) does not correlate with increasing CIN grade and carcinoma.

CONCLUSIONS

Results of the present study showed that p16, CK8, and CK17 immunostaining differed according to the degree of cervical intraepithelial lesions and SCC, and surprisingly, that staining was significantly correlated with increasing lesion grade of CIN and SCC.

Cytokeratin 17 mRNA expression has potential for diagnostic marker of oral squamous cell carcinoma

PURPOSE

Determination of marker for identification of oral squamous cell carcinoma (OSCC) is important for early diagnosis and individual therapy. Cytokeratins (CKs) like CK 19 and CK 20 are known to be useful diagnostic and prognostic markers for solid tumors. The aim of this study was to evaluate the relevance of further CKs for diagnosis of OSCC.

MATERIALS

In 10 OSCC and 5 normal mucosal samples, the expression patterns of 31 CK genes were examined by cDNA microarray in order to identify CKs with most pronounced over-expression. The results were verified for CK 17, CK 19, and CK 20 in addition to 46 OSCC samples by relative quantification (RQ) using SYBR green real-time reverse transcriptase polymerase chain reaction (RT qPCR). A correlation of the CK expressions with the tumor classification was carried out.

RESULTS

cDNA microarray analyses showed that out of all CKs, CK 17 was up-regulated strongest in OSCC compared to normal samples, and over-expression was most significantly associated with diagnosis (P = 0.002). Expression rates of CK 19 and CK 20 were not significantly different between OSCC samples and normal samples. In 56 samples analyzed by real-time RT qPCR, CK 17 was over-expressed in 53 (94.6%), CK 19 in 18 (32.1%), and CK 20 in 7 (12.5%). The over-expression of CK 17 was significantly associated with metastases of neck lymph nodes (P < 0.05). CK 19 was significantly over-expressed in T3 and T4 OSCC, in stage III and IV patients (P < 0.05), and in poorly differentiated OSCC (P < 0.03). The over-expression of CK 20 was significantly associated with metastases of neck lymph nodes (P < 0.03). Determined by RQ, the mean value of CK 17 over-expression was significantly higher than that of the other CKs (P < 0.01), and was significantly associated with T1 and T2 OSCC (P < 0.03) and with stage I and II patients (P < 0.01).

CONCLUSION

CK 19 might be linked to the clinical progression and differentiation of OSCC, and CK 20 could be associated with metastases of neck lymph nodes in OSCC. Due to the significant up-regulation and the strong over-expression, CK 17 might be the most suitable marker for diagnosis of OSCC out of the CK-family.

Proteome analysis identifies novel protein candidates involved in regeneration of the cerebellum of teleost fish

In contrast to mammals, adult teleost fish exhibit an enormous potential to regenerate neuronal tissue after injuries to the CNS. By combining a well-defined cerebellar lesion paradigm with differential proteome analysis at a post-lesion survival time of 3 days, we screened for protein candidates involved in repair of the fish brain. Out of nearly 900 protein spots detected on 2-D gels, spot intensity was significantly increased at least twofold in 30 spots and decreased to at least half the intensity of control tissue in 23 spots. The proteins associated with 24 of the spots were identified by PMF and MS/MS fragmentation. The cellular localization and the spatiotemporal patterns of two of these proteins, beta-actin and beta-tubulin, were further characterized through immunohistochemistry. Comparison of the observed changes in protein abundance with the previously characterized events underlying regeneration of the cerebellum suggests that the proteins identified are especially involved in cellular proliferation and survival, as well as axonal sprouting.

Distribution of HPV infection and tumour markers in cervical intraepithelial neoplasia from cone biopsies of Mozambican women

AIMS

To evaluate human papillomavirus (HPV) infection in whole cervical cone specimens with cervical intraepithelial neoplasia (CIN). In addition, to evaluate the relation between the presence of CIN lesions and HPV infection and the expression of Ki-67, p53, cytokeratins, Gp230 glycoprotein, and simple mucin-type carbohydrates.

METHODS

Cervical cone specimens from five patients with CIN were studied. For each specimen, serial sections encompassing the whole cone were collected (52 samples). HPV infection and HPV types were detected by the polymerase chain reaction and enzyme immunoassay. The expression of Ki-67, p53, cytokeratins, Gp230, and simple mucin-type carbohydrates was examined immunohistochemically.

RESULTS

All cases showed high risk HPV types, namely types 16, 33, 35, and 58. Four of the five patients were infected by multiple viral types. HPV-58 was always seen in CIN III, whereas HPV-35 was more frequent in CIN I. The expression of Ki-67 and p53 was higher in CIN III lesions. The expression of cytokeratins 8 and 17 showed complete or almost complete overlap with CIN III. Altered expression of Gp230, Tn, and sialyl-T was often seen in all grades of CIN.

CONCLUSIONS

When whole cervical cone specimens are evaluated the rate of multiple HPV infection is very high. The expression of cytokeratins 8 and 17 is a useful marker of CIN III.

Papillomavirus-mediated neoplastic progression is associated with reciprocal changes in JAGGED1 and manic fringe expression linked to notch activation

Infection by high-risk human papillomaviruses (HPV) and persistent expression of viral oncogenes E6 and E7 are causally linked to the development of cervical cancer. These oncogenes are necessary but insufficient for complete transformation of human epithelial cells in vivo. Intracellular Notch1 protein is detected in invasive cervical carcinomas (ICC), and truncated Notch1 alleles complement the function of E6/E7 in the transformation of human epithelial cells. Here we investigate potential mechanisms of Notch activation in a human cervical neoplasia. We have analyzed human cervical lesions and serial passages of an HPV type 16-positive human cervical low-grade lesion-derived cell line, W12, that shows abnormalities resembling those seen in cervical neoplastic progression in vivo. Late-passage, but not early-passage, W12 and progression of the majority of human high-grade cervical lesions to ICC showed upregulation of Notch ligand and Jagged1 and downregulation of Manic Fringe, a negative regulator of Jagged1-Notch1 signaling. Concomitantly, an increase in Notch/CSL (CBF1, Suppressor of Hairless, Lag1)-driven reporter activity and a decrease in Manic Fringe upstream regulatory region (MFng-URR)-driven reporter activity was observed in late-passage versus early passage W12. Analysis of the MFng-URR revealed that Notch signaling represses this gene through Hairy Enhancer of Split 1, a transcriptional target of the Notch pathway. Expression of Manic Fringe by a recombinant adenovirus, dominant-negative Jagged1, or small interfering RNA against Jagged1 inhibits the tumorigenicity of CaSki, an ICC-derived cell line that was previously shown to be susceptible to growth inhibition induced by antisense Notch1. We suggest that activation of Notch in cervical neoplasia is Jagged1 dependent and that its susceptibility to the influence of Manic Fringe is of therapeutic value.

Evidence of pluripotent human prostate stem cells in a human prostate primary xenograft model

INTRODUCTION

The phenotypic plasticity of the human prostate stem cell within human prostate tissue was examined to determine the response of the stem cell to changes in the androgenic environment.

METHODS

Prostate xenografts were transplanted into athymic nu/nu mice implanted with testosterone pellets, allowed to establish for 1 month time point, the hosts were castrated and pellets removed, and following 1 month of androgen deprivation, the hosts were stimulated with androgen for 2 days to induce proliferation of the residual population of stem cells (2-month time point).

RESULTS

Glands in benign xenografts harvested at the 1- and 2-month time points contained basal cell layers that expressed p63 and high molecular weight cytokeratin, and in which essentially all of the cellular proliferation was localized, consistent with the proposed localization of the prostate stem cell. Benign glandular structures in the xenografts were populated by basal, secretory epithelial, neuroendocrine (NE), or squamous cells overlaying the basal cell layer, whereas, adenocarcinoma glands in the xenografts resembled the original prostate cancer (CaP) tissue.

CONCLUSIONS

In this human prostate primary xenograft model, the residual stem cell population that survives transplantation, or androgen deprivation, maintains significant pluripotentiality as demonstrated by the capacity to generate progeny that differentiate along multiple lineages in response to microenvironmental signals, particularly along the secretory epithelial lineage in response to androgen, and along the NE cell lineage in response to androgen deprivation.

Detection of pelvic lymph node micrometastasis in stage IA2-IB2 cervical cancer by immunohistochemical analysis

OBJECTIVES

The objectives of this study were to (1) determine the incidence of lymph node micrometastasis in cervical cancer by immunohistochemical analysis and (2) determine if the presence of micrometastasis is a poor prognostic feature in early cervical cancer.

METHODS

We retrospectively reviewed the medical records of 62 patients who underwent radical hysterectomy and lymphadenectomy for FIGO stage IA2-IB2 cervical cancer at Stanford University Hospital from 1990 to 2000. Forty-nine patients with negative lymph nodes were identified. A total of 976 formalin-fixed paraffin-embedded pelvic lymphadenectomy specimens were serially sectioned and stained with anti-cytokeratin antibodies AE1 and AE1/CAM5.2.

RESULTS

Six patients had stage IA2 disease, 37 had stage IB1, and 6 had IB2. The mean age of the patients was 44 years (range, 24-76). Seventy-one percent had squamous cell carcinomas, 22% had adenocarcinomas, and 6% had other types. Lymph node micrometastases were immunohistochemically detected in 4 of the 49 (8.1%) patients, comprising 4 of 976 (0.41%) pelvic lymph nodes examined. Twelve of 45 (15.6%) patients with negative nodes had lymph-vascular space invasion (LVSI) whereas 3 of 4 (75%) patients with micrometastases had LVSI. At a mean follow-up time of 39.4 months, 2 of 4 (50%) patients with micrometastasis had recurrent disease, while 3 of 45 (6.7%) patients without micrometastasis developed recurrent disease.

CONCLUSIONS

These preliminary data suggest that immunohistochemical detection of pelvic lymph nodes is more frequent in patients with LVSI and may identify patients needing adjuvant chemoradiation.

Hyperproliferation, induction of c-Myc and 14-3-3σ, but no cell fragility in keratin-10-null mice

In the past, keratins have been established as structural proteins. Indeed,mutations in keratin 10 (K10) and other epidermal keratins lead to severe skin fragility syndromes. Here, we present adult K10-/- mice, which reveal a novel connection between the regulation of cell proliferation and K10. Unlike most keratin mutant mice, the epidermis of adult K10-/-mice showed no cytolysis but displayed hyperproliferation of basal keratinocytes and an increased cell size. BrdU labelling revealed a shortened transition time for keratinocytes migrating outwards and DAPI staining of epidermal sheets uncovered an impaired organization of epidermal proliferation units. These remarkable changes were accompanied by the induction of c-Myc,cyclin D1, 14-3-3σ and of wound healing keratins K6 and K16. The phosphorylation of Rb remained unaltered. In line with the downregulation of K10 in squamous cell carcinomas and its absence in proliferating cells in vivo, our data suggest that the tissue-restricted expression of some members of the keratin gene family not only serves structural functions. Our results imply that the altered composition of the suprabasal cytoskeleton is able to alter the proliferation state of basal cells through the induction of c-Myc. A previous model based on transfection of K10 in immortalized human keratinocytes suggested a direct involvement of K10 in cell cycle control. While those experiments were performed in human cultured keratinocytes, our data establish, that in vivo, K10 acts by an indirect control mechanism in trans.

Keratin expression in human tissues and neoplasms

Keratin expression in human tissues and neoplasms Keratin filaments constitute type I and type II intermediate filaments (IFs), with at least 20 subtypes named keratin 1-20. Since certain keratin subtypes are only expressed in some normal human tissues but not others, and vice versa, various tissues have been subclassified according to the pattern of keratin staining. Simple epithelia generally express the simple epithelial keratins 7, 18, 19, and 20, while complex epithelia express complex epithelial keratins 5/6, 10, 14, and 15. When an epithelium undergoes malignant transformation, its keratin profile usually remains constant. The constitution and expression patterns of keratin filaments in human epithelial neoplasms are complex and often distinctive. In this article, we first briefly review the molecular and cell biology of keratin filaments. We then focus on the expression patterns of keratin filaments in various human neoplasms.

Functional proteomics of transforming growth factor-beta1-stimulated Mv1Lu epithelial cells: Rad51 as a target of TGFbeta1-dependent regulation of DNA repair

Transforming growth factor-beta (TGFbeta) conveys regulatory signals through multiple intracellular pathways, subsequently affecting various cellular functions. To identify new targets for TGFbeta, we studied the changes in the proteome of Mv1Lu lung epithelial cells in response to TGFbeta1 treatment. Thirty-eight non-abundant protein spots, affected by TGFbeta1, were selected, and proteins were identified by peptide mass-fingerprinting (PMF). Among them, proteins involved in regulation of immune response, apoptosis, regulation of TGFbeta signalling, metabolism and DNA repair were identified. Twenty-eight of the 38 proteins are new targets for TGFbeta1, thus suggesting novel ways of integration of TGFbeta signalling in intracellular regulatory processes. We show that TGFbeta1-dependent decrease in expression of one of the new targets, Rad51, correlates with a decrease in DNA repair efficiency. This was evaluated by formation of nuclear Rad51-containing DNA repair complexes in response to DNA damage, by single cell gel electrophoresis and by cell survival assay. The TGFbeta1-dependent inhibition of DNA repair was reversed by ectopic overexpression of Rad51. Therefore, TGFbeta can promote DNA instability through down-regulation of Rad51 and inhibition of DNA repair.