Simple cytokeratins in the serum of patients with lung cancer: relationship to cell death

Two pathologic types of hepatocellular carcinoma with lymph node metastasis with distinct prognosis on the basis of CK19 expression in tumor

BACKGROUND

Few studies have investigated the pathologic types and prognosis of hepatocellular carcinoma (HCC) with lymph node metastasis (LNM). The purpose was to explore pathologic types and pertinent therapy of HCC with LNM.

METHODS

An immunohistochemical study for CK19 and OV-6 was performed on tissue microarrays of HCC with LNM (n=47) and those without LNM (n=125). The clinicopathologic factors and patient survival were analyzed.

RESULTS

Immunopositivity of CK19 and OV-6 in HCC with LNM were higher than that in 125 HCC without LNM (27.7% vs 5.6%, P=.000; 29.8% vs 12.8%, P=.009); their expressions were significantly correlated in HCC with LNM (correlation coefficient: 0.637, P=.000). The CK19 expression and tumor (T) classification of American Joint Committee on Cancer (AJCC)/International Union Against Cancer (UICC) tumor staging system were 2 independent risk factors for developing LNM (odds ratio [OR], 5.170, 95% confidence interval [CI], 1.840-14.528, P=.002; OR, 1.879, 95% CI, 1.236-2.857, P=.003). The CK19(+) group had shorter median survival (7.7 months vs 21.7 months, P=.013); CK19 expression was the independent prognostic factor for overall survival in HCC with LNM and was correlated with proliferating cell nuclear antigen labeling index and matrix metalloproteinase-9 expression (correlation coefficient: 0.484, P=.001 and 0.459, P=.001, respectively).

CONCLUSIONS

CK19 expression and AJCC/UICC T classification were 2 independent risk factors for developing LNM in HCC. CK19 expression was the independent prognostic factor for HCC with LNM. It is of clinical significance for treatment modalities to differentiate HCC with intrahepatic cholangiocarcinoma-like differentiation (CK19[+]) from one with a higher T classification (CK19[-]).

Aberrant messenger RNA splicing of the cytokeratin 8 in lung cancer

Cytokeratin 8 (CK8) is one of the cytoskeletal components and shows caspase-mediated degradation when cells undergo apoptosis. We previously reported that CK8 is highly expressed in non-small cell lung cancer (NSCLC) cell lines and increasing values of serum CK8 are significantly associated with tumor progression in patients with NSCLC. In this investigation, reverse transcriptase-polymerase chain reaction (RT-PCR) analysis in lung cancer cell lines, revealed a shorter PCR product, which differed from the wild-type product of CK8. The nucleotide sequence of the shorter PCR products and genomic DNA for CK8 demonstrated that the shorter product was an aberrantly spliced form of CK8 (AS-CK8) which lacked a caspases cleavage site within the linker lesion in exon 5. The putative protein products predicted by the mRNA of AS-CK8 were demonstrated by Western blotting with monoclonal antibodies for CK8. In addition, AS-CK8 mRNA and its protein products were highly expressed in NSCLC cell lines compared with small-cell lung cancer (SCLC) cell lines. Tissue samples obtained from NSCLC patients also expressed mRNA of AS-CK8. In conclusion, we identified aberrantly spliced CK8 (AS-CK8) which lacked a caspases cleavage site in lung cancer cell lines and primary tumors of NSCLC. AS-CK8 was preferentially expressed in NSCLC, rather than SCLC. These findings lead to speculation that cancer cells expressing AS-CK8 may have a resistance to apoptosis and may perturb keratin network formation.

Expression of cytokeratin 8 in lung cancer cell lines and measurement of serum cytokeratin 8 in lung cancer patients

It has been reported that cytokeratin 8 (CK8) can be expressed in several cancers and expression of CK8 is correlated with increased invasiveness of the tumor in vitro and in vivo. In the present study, we investigated expressions of CK8 in human lung cancer cell lines. In addition, we also evaluated the clinical significance of CK8 measurements in sera of patients with lung cancer. Expression of mRNA for CK8 was semi-quantitatively evaluated by the competitive reverse transcriptase-polymerase chain reaction (competitive RT-PCR), using human lung cancer cell lines. The level of CK8 protein in culture supernatants of lung cancer cell lines and 70 sera of patients with lung cancer was measured by enzyme-linked immunosorbent assay (ELISA). Levels of serum CK8 according to clinical parameters were also examined. The level of expression of CK8 mRNA in non-small cell lung cancer (NSCLC) cell lines was significantly high compared with that of small cell lung cancer (SCLC) cell lines (P<0.05). The level of CK8 in culture supernatants in NSCLC was significantly high compared with that of SCLC. The level of serum CK8 in patients with NSCLC was significantly high compared with that of normal non-smokers and compared with that of SCLC (P<0.05). Patients with a CK8 value of 50.0 ng/ml, or higher, had a statistically significant diminished survival compared with those patients whose CK8 values were lower. In conclusion, CK8 was preferentially expressed in NSCLC. Increasing values of CK8 were significantly associated with tumor progression and decreased survival in patients with NSCLC. Therefore, CK8 in sera may become a novel tumor marker in patients with lung cancer.

Identification of differentially expressed genes in pulmonary adenocarcinoma by using cDNA array

No clear patterns in molecular changes underlying the malignant processes in lung cancer of different histological types have been found so far. To identify critical genes in lung cancer progression we compared the expression profile of cancer related genes in 14 pulmonary adenocarcinoma patients with normal lung tissue by using the cDNA array technique. Principal component analyses (PCA) and permutation test were used to detect the differentially expressed genes. The expression profiles of 10 genes were confirmed by semi-quantitative real-time RT-PCR. In tumour samples, as compared to normal lung tissue, the up-regulated genes included such known tumour markers as CCNB1, PLK, tenascin, KRT8, KRT19 and TOP2A. The down-regulated genes included caveolin 1 and 2, and TIMP3. We also describe, for the first time, down-regulation of the interesting SOCS2 and 3, DOC2 and gravin. We show that silencing of SOCS2 is not caused by methylation of exon 1 of the gene. In conclusion, by using the cDNA array technique we were able to reveal marked differences in the gene expression level between normal lung and tumour tissue and find possible new tumour markers for pulmonary adenocarcinoma.

Detection of large molecular weight cytokeratin 8 as carrier protein of CA19-9 in non-small-cell lung cancer cell lines

It has been reported that cytokeratin 8 (CK8) is expressed in all non-small-cell lung cancers (NSCLC). We hypothesized that antigenic changes of CK8 may occur in some NSCLC cell lines. To prove this, Western immunoblot analysis using anti-human CK8 monoclonal antibodies as well as immunohistological staining of CK8 were performed in NSCLC cell lines. As a result, CK8 which had a higher molecular weight than recombinant CK8 was demonstrated in two of eight NSCLC cell lines. In addition, this CK8 contained antigenic epitopes of CA19-9. This CK8 with higher molecular weight, may have played a role in the process of invasion or metastasis of NSCLC.

Usefulness of longitudinal evaluation of Cyfra 21-1 variations in advanced lung cancer monitoring

To investigate the usefulness of Cyfra 21-1 as an indicator of therapy effectiveness and prognosis in advanced primary lung cancer, sixty-three patients were selected on the basis of a high Cyfra 21-1 serum level (> 3.3 ng/ml) at the time of diagnosis. Serial assays of Cyfra 21-1 were performed during the first three courses of chemotherapy among 63 patients. The serial-values were analysed according to response to treatment and overall survival. After three courses of chemotherapy, a 70% reduction under the initial marker's value or a return to normal was observed for 36 patients. Twenty-two (61%) of these patients presented an objective response to therapy, making Cyfra 21-1 a moderate indicator in terms of positive predictive value (PPV). However, a significant decrease of Cyfra 21-1 was observed in 88% (sensitivity) of the 25 objective responders. Cyfra 21-1 changes after one course of chemotherapy (61 patients) were not sufficient to predict the future response after three courses (sensitivity 52%, specificity 56%, PPV 45%). Among 30 clinical or radiological relapses, a 10% increase or a return upper reference limit in Cyfra 21-1 level was observed in 18 cases (sensitivity 60%, specificity 100%, PPV 100%). Survival data were available for 61 patients. No significant statistical difference (P > 0.05) was found between survival curves depending on a significant decrease of Cyfra 21-1 after the first course of chemotherapy. We can conclude that the only interest of serial Cyfra 21-1 assays may be the detection of relapse, where one observes a significant decrease of the marker correlated with an objective response to first treatment.

Periodontal implications: medically compromised patients

The presence of systemic disease in patients requiring periodontal therapy creates challenges for management. Alteration of treatment plans, with emphasis on physician consultation and preventive periodontal care, is frequently needed to minimize the impact of periodontal disease on the systemic condition. Conversely, detection and treatment of systemic disorders may impact upon the status of the periodontium and the success of periodontal therapy. The goal of holistic patient management is facilitated by a free flow of information between the patients and their medical and dental health care providers.

Assessment of five serum marker assays in patients with advanced breast cancer treated with medroxyprogesterone acetate

This study concerns five different tumour marker assays examined in the context of 94 patients with advanced breast cancer treated in a prospectively randomised trial of different doses of medroxyprogesterone acetate (MPA). MPA was administered at doses of 500 or 1000 mg daily and clinical evaluation of patients was carried out according to UICC criteria. Carcinoembryonic antigen (CEA) was selected as a standard marker, with three assays for MUC1 mucins (epithelial mucin core antigens (EMCA), EMCA2 and BR-MA immunoradiometric assay) differing in antibody specificities for different mucin epitopes. An additional novel assay for soluble cytokeratin was also evaluated as an example of an independent marker with a different nature and biology. Sensitivity of individual assays ranged between 44 (EMCA2) and 69% (cytokeratin) and the use of two assays in combination led to sensitivities as high as 84% (cytokeratin+BR-MA). The proportion of patients found to be assessable by each assay ranged between 51 (EMCA2) and 76% (cytokeratin). Of those patients whose marker changes were assessable, those receiving the higher dose of MPA displayed significant falls in marker levels after 12 weeks of treatment. This effect was not observed in patients receiving 500 mg. The change in cytokeratin levels in patients undergoing high dose MPA therapy proved to be most marked. Using the cytokeratin assay, 91% (of 23 patients) of patients with progressive disease showed at least a 25% rise in serum marker levels. Of these, 66% showed increases before disease progression was detected clinically with a mean lead time of 14 weeks. There was very little difference between the responses of the five tumour marker assays in patients with stable or responding disease, the proportion of these patients with stable or falling tumour marker levels ranging between 58% (CEA) and 77% (EMCA). We conclude that the cytokeratin assay has an application in monitoring response to therapy and predicting tumour progression in advanced breast cancer patients with assessable tumour marker profiles, especially if used in combination with a MUC1 mucin assay.