Increased natural killer cell activity correlates with low or negative expression of the HER-2/neu oncogene in patients with breast cancer

BACKGROUND

Increased expression of the HER-2/neu oncogene in breast cancer correlates with decreased estrogen receptor concentration and seems to be an important prognostic factor. The authors investigated whether there is a correlation between HER-2/neu expression and immunologic parameters representing tumor defense in patients with breast cancer.

METHOD

A Western blot analysis was used to investigate HER-2/neu expression, whereas a chromium-release assay using the K562 cell line as target was used to measure natural killer (NK) cell activity.

RESULTS

In patients with breast cancer, NK cell activity was significantly higher compared with patients with benign tumors (P = 0.006) or healthy control subjects (P = 0.002). Moreover, 23.3% of patients with breast cancer showed an overexpression of HER-2/neu protein. Within this group of patients, NK cell activity was significantly lower (45.6 +/- 16.1%) compared with the group with no HER-2/neu overexpression (57.3 +/- 11.0%). NK cell activity did not increase in patients with HER-2/neu overexpression. Thus, there was a statistically significant correlation of cytolytic effector cell function with HER-2/neu expression of the tumor (P = 0.003), and HER-2/neu overexpression correlated with a negative estrogen receptor status (P = 0.005).

CONCLUSION

These data add further evidence to previous observations from the authors' laboratory that certain tumor characteristics may be associated with reactions of the host with breast cancer.

erbB-2 and myc oncoproteins in sera and tumors of breast cancer patients

This study compares the prevalence of elevated serological levels of erbB-2 and myc proteins in 36 breast cancer patients and 25 healthy, ambulatory female controls. The controls were frequency matched to the cases by age and ethnicity. Oncoprotein levels were determined blind to the "case-control status" of the individual from whom the specimen was derived. Corresponding tissue levels were examined in tumors of the 13 cases from whom sufficient tissue was available. Serum oncoproteins were elevated as follows: erbB-2 in one control (4%) compared with nine cases (25%; PFisher's exact = 0.03); myc in no control (0%) compared with seven cases (19%; PFisher's exact = 0.02). Elevated serum levels of erbB-2 or myc oncoproteins were detected in four of the seven cases (57.1%) of in situ cancer without evidence of infiltration. In all cases with elevated serum oncoproteins where tumor tissue was available, the corresponding protein was elevated in the tumor. The three cases who had elevated preoperative serum oncoprotein levels and from whom it was possible to procure postoperative specimens had normal postoperative serum oncoprotein levels. We conclude that (a) erbB-2 and myc oncoproteins are elevated in a proportion of breast cancer patients, (b) the tumor seems to be the source of the serum elevation, and (c) these proteins may be useful as part of a panel of biomarkers of early malignant disease.

Flow cytometric detection of DNA tumor virus nuclear oncogene products in unfixed cells: saponin FACS of viral oncogene products

Immunofluorescent analysis is a standard method for detecting DNA virus oncoproteins in transformed cells. Here we demonstrate the detection of DNA virus nuclear oncoproteins by flow cytometry of unfixed cells, after saponin permeabilization. This method could to be of value in the evaluation and quantitation of oncogene products in transformed cells.

Clonality, expression and methylation patterns of the Epstein-Barr virus genomes in lethal midline granulomas classified as peripheral angiocentric T cell lymphomas

We analysed the terminal repeats of Epstein-Barr virus (EBV) in DNAs isolated from six lethal midline granuloma (LMG) biopsies. A single fused terminal fragment could be detected in each case, indicating that these angiocentric peripheral T cell lymphomas represent clonal proliferations of cells infected with EBV on a single occasion. Using reverse transcriptase-PCR, we detected EBV nuclear antigen (EBNA) 1 and latent membrane protein (LMP) 1, but not EBNA 2 messages in LMG biopsy RNAs. The splicing pattern of the EBNA 1 message was consistent with the usage of a promoter localized in the BamHI F fragment (F promoter). The BamHI W fragment repeats and LMP-coding sequences were highly methylated in all cases. In contrast, the LMP regulatory sequences were found to be hypomethylated or partially methylated, as in LMP-expressing nasopharyngeal carcinomas.

Human papillomavirus type 16 E6, E7 and L1 and type 18 E7 proteins produced by recombinant baculoviruses

Proteins derived from the E6, E7 and L1 ORFs of HPV16 and the E7 ORF of HPV18 were produced in insect cells using a baculovirus expression system. HPV ORFs were inserted into baculovirus transfer vectors pAcYM1 or pVL1393/2, and recombinant baculoviruses isolated using a combination of limiting dilution and plaque assay. Using HPV-specific antisera and monoclonal antibodies HPV proteins were identified in lysates of Spodoptera frugiperda (Sf-21) cells infected with HPV-recombinant baculovirus. Immunoreactive HPV16 E7 protein produced in Sf-21 cells had an apparent M(r) of 19 kDa, larger than that predicted from the amino acid sequence, and similar to that of native HPV16 E7 protein in HeLa and CaSki cells. The apparent M(r) of recombinant HPV18-E7, HPV16-L1 and HPV16-E6 proteins was equivalent to the M(r) values predicted from the amino acid sequence. Thermostability studies revealed that the half-life of HPV16-E7 protein in Sf-21 cell lysate was approx. 20 h at 4 degrees C, 2 h at 22 degrees C, and less than 30 min at 37 degrees C. HPV16 L1, HPV16 E7 and HPV18 E7 proteins were predominantly localised in the nucleus of recombinant baculovirus-infected Sf-21 cells, whereas recombinant HPV 16 E6 protein was localised in both the cytoplasm and nucleus of infected insect cells. Northern blot analysis of RNA derived from insect cells infected with vAc16E6E7, a recombinant baculovirus containing both HPV16 E6 and E7 ORF's, revealed the presence of only E6 ORF transcripts, suggesting that the splicing of RNA products derived from the E6 and E7 ORF's, as observed in cervical cancer-derived cell lines, is not performed in insect cells. Baculovirus-derived HPV proteins have similar biological properties to the native proteins and should be suitable for studies on the immunology of HPV.

Detection of Epstein-Barr virus nucleic acid sequences and protein in nodal T-cell lymphomas: relation between latent membrane protein-1 positivity and clinical course

Forty-six nodal T-cell lymphomas, classified according to the updated Kiel classification, were investigated for the presence of Epstein-Barr virus (EBV) DNA by polymerase chain reaction (PCR), EBER 1 and 2 (EBER 1/2) and latent membrane protein-1 (LMP-1) expression. A combination of RNA in situ hybridization and immunohistochemistry was used to establish the phenotype of the Epstein-Barr virus harbouring cells. In 21 of 45 cases Epstein-Barr virus DNA sequences could be detected with the polymerase chain reaction. In 15 cases (14 of 21 EBV PCR positive cases), EBER 1/2 positive cells could be demonstrated. As judged by morphology, EBER 1/2 expression was found in nonneoplastic and neoplastic lymphoid cells. Double staining revealed that more than 80% of the EBER 1/2 harbouring cells, lacked B-, T- or histiocytic markers, suggesting down regulation of T- and B-cell markers by Epstein-Barr virus. In eight of 15 cases some EBER 1/2 positive T-cells (CD3, CD45RO, CD43) morphologically resembling tumour cells were found. In nine of 14 cases tested EBER 1/2 positive non-neoplastic B-cells (CD20) were seen. Based on in situ hybridization results, four patterns of EBER 1/2 positive cells were found, i.e. single cells (< 1 per medium power field (mpf), n = 3), scattered (1-25/mpf, n = 4), clustered (26-100/mpf, n = 5) and diffuse (> 100/mpf, n = 3). In eight of 15 cases a clustered or diffuse pattern of EBER 1/2 positive cells was found and these lymphomas were therefore considered to be strongly associated with Epstein-Barr virus. In these lymphomas LMP-1 expression was found to be associated with an aggressive clinical course and hepatosplenomegaly.

HER-2/neu: a differentiation marker in adenocarcinoma of the esophagus

Adenocarcinoma of the esophagus is an aggressive malignancy which is increasing in frequency. The HER-2/neu oncogene product is a putative differentiation marker which exhibits decreased expression in colon carcinoma, while there is overexpression in breast and ovarian cancers. We analyzed the relationship of cell differentiation to HER-2/neu expression in esophageal adenocarcinoma using immunohistochemistry on formalin-fixed, paraffin-embedded material from 14 patients whose tissue contained normal, dysplastic, and malignant features. HER-2/neu expression was detected in 1 of 14 biopsy specimens and 2 of 9 resection specimens. The oncoprotein staining was greatest in normal tissue, less in dysplastic tissue, and not detected in malignant tissue. Our findings, similar to what is seen in the colon, suggest that the HER-2/neu oncogene product is a differentiation marker which is lost in esophageal adenocarcinoma.

Loss of thyrotropin regulation and transforming growth factor beta-induced growth arrest in erbB-2 overexpressing rat thyroid cells

Amplification of erbB-2 gene and overexpression of gp185erbB-2 gene product is found in approximately one-third of primary human breast and ovarian cancer. Overexpression of gp185erbB-2 was recently found in human papillary thyroid carcinomas, but not in thyroid follicular carcinomas or adenomas. The erbB-2 gene encodes a cell surface growth factor receptor with intrinsic tyrosine kinase activity. Wild type human erbB-2 has been shown to act as a potent oncogene when overexpressed in mouse fibroblasts. To test whether overexpression of normal human erbB-2 gene can transform epithelial differentiated rat thyroid cells, these cells were infected with a recombinant retroviral expression vector containing the erbB-2 protooncogene. Rat thyroid cells expressing high levels of gp185erbB-2 do not display a fully transformed and tumorigenic phenotype. However, the isolated cell clones that overexpress gp185erbB-2, show changes in their growth properties if compared to normal thyroid cells, since they can grow in absence of thyrotropin, the main growth factor controlling thyroid cell proliferation in vitro, and do not respond to the growth inhibitory effect of transforming growth factor beta.

Establishment and characteristics of two new human mammary carcinoma lines serially transplantable in nude mice

Two human mammary carcinomas of postmenopausal women were successfully transplanted into nude mice. Both tumours were classified as epidermal-growth-factor-, oestradiol- and progesterone-receptor-negative and c-erbB2-protein-positive. Histological studies of the primary tumours (4000 and 4151) revealed ductal invasive mammary carcinomas. In the first passages the precondition for the growth of breast carcinoma 4000 were pretreatments of the nude mice with oestradiol and peanut oil before transplantation. The mammary carcinomas 4000 and 4151 described here are suitable for in vivo testing of antineoplastic substances and for biological studies.

Cutaneous and mucosal human papillomavirus E4 proteins form intermediate filament-like structures in epithelial cells

Human papillomavirus (HPV) type 1 (HPV 1) is associated with benign cutaneous warts and HPV type 16 (HPV 16) with mucosal epithelial lesions that can progress to invasive carcinoma. The primary structure of the HPV E4 proteins is not highly conserved between types and their role in the viral life cycle is still unknown. A large panel of Simian virus 40 (SV40)-transformed human and monkey epithelial and fibroblast cell lines were infected with recombinant SV40/HPV1 E4 or SV40/HPV 16 E4 viruses and the expression of the viral proteins was analyzed by indirect immunofluorescence. Both HPV 1 and HPV 16 E4 proteins formed extensive and organized filamentous cytoplasmic networks that co-localized with the cytokeratin intermediate filaments. However, only HPV 16 E4 induced the collapse of the cytokeratin filaments. Furthermore, when both virus type E4 proteins were expressed within the same cell the collapse of the HPV 16 E4 filaments did not induced the collapse of the HPV 1 E4 network. Similar E4 filamentous structures were also observed in the cytoplasm of cells of the parabasal layer of an HPV 1-induced experimental wart. The HPV 16 E4 protein formed cytoplasmic networks in all SV40-transformed cell lines examined, but HPV 1 E4 only formed filamentous networks in human keratinocytes and in a monkey stomach epithelial cell line. In keratinocyte cells HPV 1 E4 species of 16, 17, 32, and 34 kDa were expressed, while in Cos-1 cells (in which no E4 networks are formed) only the 17 and 34 kDa polypeptides were found. The specific behavior of E4 proteins of cutaneous and mucosal HPVs expressed in cultured cells may suggest that these viral proteins have evolved to perform a similar function at different epithelial sites.

Effects of short-term tamoxifen administration in patients with invasive cervical carcinoma

Cervical cancer is not considered a hormone-responsive tumor in spite of the presence of estrogen receptors (ER) and progesterone receptors (PgR) in some of them. Endocrine treatments have not achieved clinical responses, however, tamoxifen has been reported to induce PgR and to inhibit cell growth of many cervical carcinoma cell lines. In this study we investigated whether tamoxifen administration affects the histopathological characteristics of cervical cancer and the expression of ER, PgR, HER-2/neu and p53 protein. Nineteen patients with invasive cervical cancer free of previous treatments were studied. The triphenylethylene antiestrogen tamoxifen was given orally during 10 days (20 or 40 mg/day). Pre- and post-tamoxifen biopsies were evaluated using slides stained with hematoxylin and eosin and immunostained (ER, PgR, HER-2/neu, p53, PCNA, keratin, heat shock protein 27,000 daltons). Estrogen receptors were present in 37% and PgR in 16% of the biopsies from untreated patients. Only one case that was PgR-negative before tamoxifen administration showed weak PgR-positivity following antiestrogen administration. No obvious changes were observed in ER, HER-2/neu and p53 proteins. A statistically significant decrease in the number of mitotic figures was obtained in 16% (3/19) of the post-tamoxifen biopsies and two of them showed higher differentiation. The results showed that tamoxifen did not induce changes in estrogen-regulated proteins in cervical cancer. However, the data showed that certain cervical carcinomas had changes in their proliferation and differentiation levels following tamoxifen administration. These findings suggest that tamoxifen may affect some cervical cancer tissues by a hormone-independent mechanism(s).

Co-localization of the tumor-suppressor protein p53 and human papillomavirus E6 protein in human cervical carcinoma cell lines

The loss of the tumor-suppressor activity of p53, either by mutation or by interaction with the human papillomavirus (HPV) E6 protein, is considered to be an important mechanism in the carcinogenesis of cervical cancer. We have studied the cytological distribution of these proteins in human cervical carcinoma cell lines using polyclonal anti-p53 and monoclonal anti-E6 antibodies. The antibody specificity was confirmed by immunoblot and immunocompetition analyses. The intracellular localization of p53 and E6 was detected using the techniques of conventional and three-dimensional confocal microscopy. In the HPV-18 or -16 integrated cell lines, HeLa, CaSki and SiHa, viral oncoprotein E6 and endogenous tumor-suppressor protein, p53, were observed by immunofluorescence in the cytoplasm; p53 also had a weak punctate staining in the nuclei of HeLa and CaSki cells. In the HPV-negative cervical carcinoma cell lines, C-33A and HT-3, which have mutated p53, p53 was localized predominantly to the nucleus, with C-33A cells having elevated levels of p53 compared with the other cell lines. High spatial resolution imaging, using confocal microscopy, was performed on the cells after double fluorescence staining for p53 (fluorescein) and E6 (rhodamine). The images showed that both p53 and E6 had similar cytoplasmic distributions, which implied that these two proteins may exist as a cytoplasmic complex. To substantiate this implication, fluorescence resonance energy transfer microscopy was performed, which provided direct evidence of a close association between p53 and E6 within individual HeLa cells. The results from this study support the theory that p53 protein binds HPV-16/18 E6 protein in the cell cytoplasm, thus preventing p53 from exerting its tumor-suppressor function in the nucleus. Hence, inactivation of wild-type p53 by p53-E6 complex formation in cervical cancer may be a critical step in malignant transformation.

The human papillomavirus type 6 and 16 E5 proteins are membrane-associated proteins which associate with the 16-kilodalton pore-forming protein

The human papillomavirus (HPV) E5 proteins are predicted from DNA sequence analysis to be small hydrophobic molecules, and the HPV type 6 (HPV-6) and HPV-11 E5 proteins share several structural similarities with the bovine papillomavirus type 1 (BPV-1) E5 protein. Also similar to the BPV-1 E5 protein, the HPV-6 and HPV-16 E5 proteins exhibit transforming activity when assayed on NIH 3T3 and C127 cells. In this study, we expressed epitope-tagged E5 proteins from both the "low-risk" HPV-6 and the "high-risk" HPV-16 in order to permit their immunologic identification and biochemical characterization. While the HPV-6 and HPV-16 E5 proteins fail to form disulfide-linked dimers and oligomers, they did resemble the BPV-1 E5 protein in their intracellular localization to the Golgi apparatus, endoplasmic reticulum, and nuclear membranes. In addition, the HPV E5 proteins also bound to the 16-kDa pore-forming protein component of the vacuolar ATPase, a known characteristic of the BPV-1 E5 protein. These studies reveal a common intramembrane localization and potential cellular protein target for both the BPV and HPV E5 proteins.

Overexpression of HER2/neu oncogene in human pancreatic carcinoma

The HER2/neu oncogene encodes a transmembrane protein that possesses intrinsic tyrosine kinase activity. Its overexpression has been associated with the malignant phenotype. In this study we examined HER2/neu expression in the normal and cancerous human pancreas. In the normal pancreas HER2/neu immunostaining was observed in acinar and ductal cells. HER2/neu immunoreactivity was expressed in 34 of 76 (45%) pancreatic carcinomas. There was a significant correlation between tumors with well-differentiated histology and HER2/neu expression. Northern blot analysis demonstrated HER2/neu mRNA expression in the normal pancreas and in situ hybridization confirmed its distribution in both acinar and ductal cells. In cancer tissues Northern blot analysis indicated that HER2/neu mRNA levels were elevated in 13 of 25 (52%) of the tumors in comparison with the normal tissues. In addition, in situ hybridization demonstrated a strong but heterogenous distribution of mRNA grains in these tumors. Southern blot analysis did not demonstrate HER2/neu gene amplification in any of the tumors. These data indicate that the HER2/neu protein is synthesized in the normal exocrine pancreas and is frequently overexpressed in well-differentiated adenocarcinomas of the pancreas as a result of increased HER2/neu mRNA levels.

Quantification of HPV-16 E6-E7 transcription in cervical intraepithelial neoplasia by reverse transcriptase polymerase chain reaction

Human papillomavirus type 16 (HPV-16) is associated with neoplastic lesions of the uterine cervix. Viral transforming functions have been localized to the E6-E7 open reading frame (ORF) and this ORF is conserved consistently in cervical intraepithelial neoplasia (CIN). Two mRNAs, generated by alternative splicing, are expressed from the E6-E7 ORF. These are known as E6*I and E6*II, and potentially encode the viral E7 and E6 proteins, respectively. It is believed that the HPV-16 transforming ability is mediated by the E6 and E7 proteins. A quantitative RT-PCR assay, developed by us to characterize the relative expression of E6-E7 spliced transcripts, was applied to exfoliated cervical cells obtained from patients in varying stages of clinically defined CIN and who were infected with HPV-16. The relationship between viral expression, disease stage, oral contraceptive use and age was studied. No association was observed between age or oral contraceptive use and HPV-16 E6-E7 expression. However, when both E6*I and E6*II were detected, a direct correlation was observed between relative proportions of E6*I/E6*II mRNAs greater than 95%/5% and increased disease severity. This study underscores the importance of the relationship between quantities of viral transforming gene transcript and the course of cervical disease. It also suggests that quantification of HPV-16 E6-E7 transcription may be useful as a prognostic tool to identify women who are at increased risk of developing cervical cancer.

The neu-oncogene product in serum and tissue of patients with breast carcinoma

BACKGROUND

A soluble 105 kD neu-related protein is detectable in conditioned medium from breast cancer cells expressing the neu-oncogene product and in serum of nude mice bearing tumors that overexpress neu-oncogene.

PATIENTS AND METHODS

In 100 patients with primary (n = 33) relapse-free (n = 6) and metastatic (n = 61) breast carcinoma the serum levels of the soluble neu-related protein were investigated by ELISA techniques. Median age was 57 years, range 26-89 years.

RESULTS

The neu-protein serum levels were below 40 HNU/ml (human neu-antigen unit) in 72 patients and 40 or more HNU/ml in 28 patients. In 30 patients with primary breast carcinoma, tested before mastectomy, all serum-neu-protein samples were negative. However, 26 of 61 metastasized patients (43%) were serum-neu-protein-positivity. In disseminated disease (n = 61), serum-neu-protein-positivity was more likely to be seen in patients with visceral metastases (18/33 = 54%), than in patients with nonvisceral metastases (8/28 = 28%). Furthermore, monitoring of the serum-neu-protein levels reflected clinical course. For 53 patients original paraffin-embedded tumor material was available for studying immunohistochemical neu-protein expression. In 39/53 (73%) patients immunohistochemical and ELISA data showed corresponding results. In 27/30 (90%) patients, from whom sera and tissue could be obtained at the same time at primary mastectomy, results of immunohistochemistry in primary tumor and serum ELISA were negative and mutually confirmatory. However, the other three patients were positive for immunohistochemical neu-protein expression in primary tumor but negative for serum-neu-protein expression.

CONCLUSIONS

Our results suggest that patients with advanced breast cancer and an elevated serum-neu-protein level may have a poor clinical outcome. This test might be a useful tool for monitoring patients with advanced breast carcinoma, but not those with early disease. Further prospective studies are warranted to elucidate the question of whether this test can contribute to determining prognosis and treatment strategies.

Overexpression of Her-2/neu may be an indicator of poor prognosis in prostate cancer

Previous reports have shown that Her-2/neu oncogene expression in human breast cancer and ovarian cancer may be associated with poorer prognosis. We report the expression of Her-2/neu on fresh samples of known prostatic adenocarcinoma but not on those of benign prostatic hypertrophy. Using a monoclonal antibody (TA1) directed against human Her-2/neu oncogene product and an immunohistochemical staining method, no Her-2/neu expression was noted with benign prostatic hypertrophy (15 samples). With prostatic adenocarcinoma samples, a subset (9 of 25) showed overexpression of Her-2/neu. Such overexpression is correlated with higher histological grade, higher stage of disease, and high S phase and aneuploidy on flow cytometric analysis. These findings suggest that Her-2/neu may be a prognostic marker in prostate cancer as well.

Expression of Epstein-Barr virus latent gene products and related cellular activation and adhesion molecules in Hodgkin's disease and non-Hodgkin's lymphomas arising in patients without overt pre-existing immunodeficiency

Epstein-Barr virus (EBV) recently has been associated with Hodgkin's disease (HD) and the EBV genome was found in CD30-positive Reed-Sternberg cells. Therefore, tissue sections from 25 cases of HD, 35 cases of CD30-positive non-Hodgkin's lymphoma (NHL) (seven CD30-positive anaplastic large cell lymphomas [ALCLs] and 28 CD30-positive non-ALCLs), and 12 cases of CD30-negative NHL that previously had been screened for the presence of EBV by polymerase chain reaction and DNA in situ hybridization were studied by immunohistochemistry for the expression of the latent EBV proteins, latent membrane protein (LMP), and Epstein-Barr nuclear antigen-2 (EBNA-2). We also analyzed the expression of the B-cell activation molecule CD23 and the adhesion molecules LFA-1/CD11a and ICAM-1/CD54 because the upregulation of these molecules by LMP and/or EBNA-2 in vitro has been related to the EBV-induced lymphocyte growth. Latent membrane protein expression was found in Reed-Sternberg cells in nine of 25 cases (36%) of HD and in large, occasionally Reed-Sternberg-like tumor cells in six of 47 cases (12%) of NHL; these six tumors were CD30-positive, histologically high-grade NHL (one CD30-positive ALCL and five CD30-positive non-ALCLs). All the LMP-positive cases were also polymerase chain reaction EBV positive while LMP expression was not found in polymerase chain reaction EBV-negative HD and NHL. No staining for EBNA-2 was detected in our series. In view of the transforming potential of the LMP, these findings suggest that EBV may be associated with the development of some cases of HD and CD30-positive NHL. These findings also suggest a correlation between the expression of LMP and the detection of CD30 in tumor cells of HD and NHL. In contrast, no correlation was found between the expression of LMP and the detection of CD23, LFA-1/CD11a, and ICAM-1/CD54 in tumor cells of HD and NHL.

Novel protein kinases expressed in human breast cancer

The family of protein kinases includes many oncogenes and growth-factor receptors, as well as genes that are involved in cell-cycle regulation. We have identified protein kinases expressed in a human breast-cancer cell line, 600PEI, and a primary human breast carcinoma, using PCR cloning techniques based on consensus sequences in the kinase domain. Twenty-five different protein kinases were isolated, including 3 novel putative tyrosine kinases (designated TK1, TK2, and TK5), and 2 novel putative cell-cycle-associated serine/threonine kinases (designated STK1 and STK2). TK1 is a new member of the src family of kinases that is expressed predominantly in epithelial cells. TK2 is homologous to the receptor kinase, HEK, and TK5 appears to be another member of the JAK family of kinases. The novel serine/threonine kinases, designated STK1 and STK2, were homologous to the human cdc2 and the Aspergillus nimA genes. We subsequently analyzed the levels of expression of all of these protein kinases in a panel of human breast carcinomas, using PCR-based methods. This analysis revealed different expression profiles in different primary breast carcinomas and, therefore, may determine new molecular sub-sets of human breast cancer.

Expression of hormone receptors, cathepsin D, and HER-2/neu oncoprotein in normal colon and colonic disease

BACKGROUND

Chronic ulcerative colitis and familial adenomatous polyposis are associated with an increased risk of colorectal carcinoma. Currently, there are no reliable methods to assess carcinoma risk.

METHODS

Several prognostic factors known to be useful in breast carcinoma were determined in 102 specimens of colonic mucosa from 38 patients: 22 specimens from "normal," non-neoplastic colon, 49 from chronic ulcerative colitis, 10 from Crohn's colitis, 14 from familial adenomatous polyposis, four from mucosa adjacent to carcinoma, and three from colon carcinoma. Expression of estrogen receptor, progestin receptor, epidermal growth factor receptor, HER-2/neu (c-erb B-2) oncoprotein, and cathepsin D were determined.

RESULTS

Epidermal growth factor receptor expression was higher in chronic ulcerative colitis, Crohn's colitis, familial adenomatous polyposis, and colon carcinoma and varied with location within the colon for chronic ulcerative colitis, Crohn's colitis, and familial adenomatous polyposis. Epidermal growth factor receptor expression in mucosa adjacent to carcinoma was similar to that in "normal" colon.

CONCLUSION

Further analyses are needed to determine which parameters are related to and possibly predictive of increased carcinoma risk.

The state of p53 in primary human cervical carcinomas and its effects in human papillomavirus-immortalized human cervical cells

Wild-type (wt) p53 acts as a tumor suppressor, while certain mutant type (mt) p53 may exhibit 'oncogenic' function. We have recently demonstrated that human papillomavirus type 18 (HPV-18) E6 can partially overcome the growth-suppressive effects of wt p53, but it remains unclear what role p53 plays in cervical carcinogenesis. In this report, we have examined nine HPV-immortalized human cervical epithelial cell lines and 13 HPV-positive and two HPV-negative primary cervical cancers for p53 mutations by polymerase chain reaction--single-strand conformation polymorphism (PCR-SSCP). None of them contained p53 mutations in exons 5-9 where most p53 mutations in human tumors have been found. The entire p53-coding region of the two HPV-negative cervical cancers was sequenced and no mutations were noted. In order to examine the effects of wt p53 and mt p53 on HPV-immortalized human cells, we transfected HPV-immortalized cell lines with wt p53 and a mt p53 (mtp53Val-135). The results indicate that HPV-immortalized cells cannot tolerate large amounts of exogenous wt p53, while mt p53Val-135 can enhance transformation of these cells. The results support the notion that inactivation of wt p53 by E6 may be important for HPV-associated transformation and also suggests that mt p53 can act as an oncogene in HPV-immoralized human cells.

Altered glycosylation of the env-sea oncoprotein inhibits intracellular transport and transformation

The transforming gene product of the S13 avian erythroblastosis virus, env-sea, is a member of the growth factor receptor class of tyrosine kinases. The env-sea precursor protein gp155env-sea is proteolytically processed into the mature cleavage products gp85env and gp70env-sea, which are subsequently terminally glycosylated and transported to the cell surface. Previous studies have shown that the abnormal glycosylation of gp155env-sea induced by the carbohydrate processing inhibitor castanospermine blocks the proteolytic cleavage of gp155env-sea and impairs its transforming ability. We have shown recently that an uncleaved but fully glycosylated sea-encoded protein retains the ability to transform chicken embryo fibroblasts, indicating that proteolytic processing is not essential for transformation by the env-sea tyrosine kinase. To address the question of how castanospermine blocks transformation by env-sea, differential sucrose gradient centrifugation was performed on env-sea-transformed cells treated with the inhibitor. This report shows that no surface forms of env-sea could be detected in inhibitor-treated cells, suggesting that castanospermine acts by blocking the transport of sea-encoded proteins to the cell surface.

Papilloma virus immortalized tracheal epithelial cells retain a well-differentiated phenotype

Human airway epithelial cell lines that retain phenotypic properties representative of the native tissue will be useful physiological models. Human papilloma viral (HPV) genes can immortalize human genital keratinocytes and breast and bronchial epithelia. We transfected cystic fibrosis (CF) and normal tracheobronchial epithelial cell cultures with DNA encoding the HPV-18 E6 and E7 genes and characterized phenotypic properties of resultant cell lines. Of the 11 CF clones isolated, 6 developed a polarized phenotype with vectorial ion transport and membrane-specific expression of histamine and purinergic receptors. The ion transport properties of these lines differed from the normal lines and approximated those of primary CF airway epithelial cell cultures more closely than do those of cell lines transformed with the simian virus 40 large T gene. When transplanted into denuded tracheal grafts, these cells can differentiate into ciliated and secretory phenotypes. We conclude that HPV-18 E6 and E7 genes are sufficient to transform human airway epithelial cells and that the resultant cell lines express differentiated phenotypic properties that approximate those of the native epithelium.