Expression of oligodendrocytic mRNAs in glial tumors: changes associated with tumor grade and extent of neoplastic infiltration

We examined the expression of glial- and neuronal-specific mRNAs within human gliomas using in situ hybridization. We found that low-grade astrocytomas contained a high number of proteolipid protein (PLP) mRNA-positive cells and that the number of PLP-stained cells decreased markedly with increasing tumor grade. Interestingly, the ratio of PLP mRNA-stained cells:myelin basic protein (MBP) mRNA-stained cells in normal white matter and low-grade astrocytoma was about 2:1 but approached 1:1 with increasing tumor grade. This parameter appeared to be a good indicator of tumor infiltration in astrocytomas, so we tested this in the analysis of other gliomas. Unlike astrocytomas, oligodendrogliomas were found consistently to contain few PLP mRNA- or MBP mRNA-expressing cells. In contrast, gemistocytic astrocytomas, typically highly invasive tumors, contained high numbers of PLP-positive cells and a ratio of PLP mRNA:MBP mRNA-stained cells of about 1.5:1, similar to low-grade astrocytomas. Nonradioactive in situ hybridization also enabled the morphological identification of specific cells. For example, gemistocytic astrocytes, which were found to be strongly vimentin mRNA positive, contained little glial fibrillary acidic protein mRNA and did not stain for PLP or MBP mRNAs. Neuronal mRNAs, such as neurofilament 68, were observed in small numbers of entrapped neurons within gliomas but were uninformative with respect to predicting tumor grade. Our results suggest that oligodendrocytes survive low-grade tumor infiltration and that glial tumor cells, unlike cell lines derived from them, do not express oligodendrocyte or neuronal mRNAs. In addition, the expression of mRNAs for the two major myelin protein genes, PLP and MBP, could be used to predict the grade and extent of tumor infiltration in astrocytomas.     

Dysregulated expression of CD66a (BGP, C-CAM), an adhesion molecule of the CEA family, in endometrial cancer

CD66a (BGP, C-CAM) is an adhesion molecule of the carcinoembryonic antigen family that has been shown to be down-regulated in colorectal, prostate, and breast cancers. The purpose of the present study was to determine its expression pattern in the normal human endometrium and in endometrial neoplasia. For this purpose, we performed immunohistochemistry using the 4D1/C2 monoclonal antibody on a series of 24 normal endometrial samples and 47 endometrial carcinomas. Strong CD66a expression was observed in glandular and luminal epithelial cells of the normal endometrium with a consistent localization at the apical poles of these cells throughout the cycle. In late secretory (premenstrual) phase, loss of cellular polarity resulted in a membranous expression pattern in some glandular cells. In the analyzed tumor samples increasing areas with a complete loss of expression were observed with increasing malignancy grade. The apical expression pattern of the normal epithelium was changed to a membranous all-around pattern in 55% of the tumors, mostly in solid areas. This change correlated with malignancy grade and could be observed in 3 of 15 G1 tumors, 4 of 12 G2 tumors, 11 of 12 G3 tumors, and 8 of 8 serous-papillary carcinomas. Areas with membranous expression pattern could be observed along with areas with a normal apical expression pattern in lower grade carcinomas and with areas with complete loss of expression in high grade tumors. Northern blot analysis showed a loss of mRNA expression in tumor samples and HEC-1B endometrial adenocarcinoma cells. Loss of protein expression in the tumor samples was also observed by Western blot. In conclusion, CD66a protein expression is dysregulated in endometrial carcinomas, showing reduction or loss of expression with increasing malignancy grade and a change from the apical to a membranous localization.     

NM23 gene expression in human breast carcinomas: loss of correlation with cell proliferation in the advanced phase of tumor progression

NM23 is a protein associated with tumor progression, expressed in all tissues and in human tumors. Reduced expression of NM23.H1 is related to high incidence of lymph node and distant metastasis or to poor prognosis of the patient in several human malignant tumors. In this study we analyze NM23 expression in non-neoplastic mammary tissues surrounding the tumoral lesions, in human mammary carcinomas and in lymph node metastasis. Our analysis shows that NM23.H1 expression is lower in the mammary cells surrounding the tumor than in the tumor itself. In the primary tumors we observed a negative trend between degree of local invasion and level of NM23.H1 expression. A further decrease of NM23.H1 was detected in the invasive tumors that metastasized to axillary lymph nodes and in the metastasis. NM23.H2 was always more highly expressed than NM23.H1, and reduced expression of NM23.H1 but not NM23.H2 was concordant with the presence of lymph node metastasis or local invasiveness of the primary tumor. A positive correlation between NM23.H1 mRNA content and cell growth rate of breast tumor cells has been confirmed. However, this trend was not maintained in cancer cells from tumors that metastasized to axillary lymph nodes and in metastatic cells; in these 2 situations the NM23.H1 mRNA content varied without any relationship to the proliferative rate of the cells. In addition, in comparison with the initial tumor, the metastatic cell population showed a strong decrease of NM23.H1 expression and increased proliferative activity.     

Immunohistochemical analysis of metallothionein in astrocytic tumors in relation to tumor grade, proliferative potential, and survival

BACKGROUND: Metallothionein (MT) is the name for a family of predominantly intracellular protein thiol compounds involved in anticancer drug resistance. For certain tumors, MT is related to grade of tumor malignancy and prognosis. The authors evaluated the expression of MT in 114 astrocytic tumors in relation to the proliferative potential of tumors and the survival of patients. METHODS: Paraffin embedded tissue sections were stained with monoclonal anti-metallothionein and MIB-1 Ki-67 antibodies by avidin-biotin complex immunohistochemistry. RESULTS: MT expression was observed in 2 of 6 pilocytic astrocytomas, in 10 of 24 Grade 2 astrocytomas, in 16 of 25 anaplastic astrocytomas, and in 47 of 59 glioblastomas. In addition to the tumor cells, microvascular endothelial proliferation and smooth muscle of tumor vessel walls were frequently MT positive. The glioblastomas had a significantly higher percentage of MT positive cells compared with low grade (P < 0.0001) and anaplastic (P < 0.04) astrocytomas. MT expression in astrocytomas had no correlation with tumor recurrence. The mean Ki-67 labeling index (LI) was significantly higher in the high grade (3-4) compared with the low grade (1-2) astrocytomas. MT positive astrocytic tumors had statistically significantly higher mean Ki-67 LI compared with MT negative tumors, irrespective of histologic grade. Although the levels of MT and Ki-67 LI varied in individual tumors, the mean Ki-67 LI increased in parallel to the increasing MT staining grade, and this difference attained statistical significance only for glioblastoma. MT positive anaplastic astrocytoma and glioblastoma patients did not survive as long as the MT negative patients, although this difference attained statistical significance only for anaplastic astrocytoma. CONCLUSIONS: The current study suggests that MT might play a significant role in the growth of astrocytic tumors, with an acquired enhanced ability to produce MT as the malignant potential of a tumor increases.     

Immunohistochemical analysis of progesterone receptor and Ki-67 labeling index in astrocytic tumors

BACKGROUND: Intracranial tumors such as meningiomas express steroid hormone receptors but little is known regarding progesterone receptor (PR) in astrocytic tumors. The authors evaluated expression of PR in 86 astrocytic tumors in relation to tumor proliferative potential. METHODS: Paraffin embedded tumor sections were stained with polyclonal antiprogesterone antibody by the peroxidase-antiperoxidase method and with monoclonal MIB-1-Ki-67 antibody by avidin-biotin complex immunohistochemistry. RESULTS: Sixty-three of the 86 astrocytic tumors (73%) showed positive PR immunoreactivity. PR expression was observed in 4 of 9 pilocytic astrocytomas, 13 of 24 Grade 2 astrocytomas, 15 of 20 anaplastic astrocytomas, and 31 of 33 glioblastomas. In addition to the tumor cells, cells of microvascular endothelial proliferation and the smooth muscle of tumor vessel walls were frequently PR positive. Glioblastomas had a significantly higher percentage of PR positive cells compared with anaplastic (P < 0.0008) and low grade (P < 0.0001) astrocytomas. Patients with PR positive astrocytomas were of an older age than patients with PR negative astrocytomas (48.71 +/- 21.95 years vs. 37.09 +/- 24.69 years; P < 0.04). The mean Ki-67 labeling index (LI) was significantly higher in the high grade (3-4) astrocytomas compared with low grade (1-2) astrocytomas (P < 0.0001). PR positive astrocytic tumors had higher Ki-67 LI than PR negative tumors. PR expression was not correlated with tumor recurrence and patient survival. CONCLUSIONS: The current study suggests that PR in the astrocytic tumors correlates with histologic grade and PR may participate in the growth of these tumors and tumor angiogenesis. The measurement of PR in these tumors may indirectly represent tumor growth potential.     

Distinct altered patterns of p27KIP1 gene expression in benign prostatic hyperplasia and prostatic carcinoma

BACKGROUND: The p27KIP1 gene, whose protein product is a negative regulator of the cell cycle, is a potential tumor suppressor gene; however, no tumor-specific mutations of this gene have been found in humans. This study was undertaken to identify and to assess potential alterations of p27KIP1 gene expression in patients with benign prostatic hyperplasia (BPH) and patients with prostate cancer. METHODS: We analyzed 130 prostate carcinomas from primary and metastatic sites, as well as prostate samples from normal subjects and from patients with BPH. Immunohistochemistry and in situ hybridization were used to determine the levels of expression and the microanatomical localization of p27 protein and messenger RNA (mRNA), respectively. Immunoblotting and immunodepletion assays were performed on a subset of the prostate tumors. Associations between alterations in p27KIP1 expression and clinicopathologic variables were evaluated with a nonparametric test. The Kaplan-Meier method and the logrank test were used to compare disease-relapse-free survival. Prostate tissues of p27Kip1 null (i.e., knock-out) and wild-type mice were also evaluated. RESULTS: Normal human prostate tissue exhibited abundant amounts of p27 protein and high levels of p27KIP1 mRNA in both epithelial cells and stromal cells. However, p27 protein and p27KIP1 mRNA were almost undetectable in epithelial cells and stromal cells of BPH lesions. Furthermore, p27Kip1 null mice developed enlarged (hyperplastic) prostate glands. In contrast to BPH, prostate carcinomas were found to contain abundant p27KIP1 mRNA but either high or low to undetectable levels of p27 protein. Primary prostate carcinomas expressing lower levels of p27 protein appeared to be biologically more aggressive (two-sided P = .019 [Cox regression analysis]). CONCLUSIONS/IMPLICATIONS: On the basis of these results, we infer that loss of p27Kip1 expression in the human prostate may be causally linked to BPH and that BPH is not a precursor to prostate cancer.     

Renal myxoma. A report of two cases and review of the literature

Renal myxomas are rare neoplasms. Seven cases have been reported, of which only two are convincingly diagnosed as myxoma; the remaining cases exhibit features of sarcoma, fibroepithelial polyp, or myxolipoma. We report two additional cases; one in a 52-year-old man and another in a 68-year-old woman. They were discovered incidentally by radiological examination. The resected kidney in both patients contained a well-demarcated gelatinous intraparenchymal tumor, which consisted of occasional slender spindle cells scattered in an abundant myxoid stroma, closely resembling myxomas of other sites. The tumor cells showed immunoreactivity for vimentin but not for S-100 protein, epithelial membrane antigen (EMA), CAM 5.2, HHF-35, or smooth muscle actin. Ultrastructural features were of fibroblast-like cells with an elaborate network of cytoplasmic processes. The differential diagnosis of myxoid tumors of the kidney includes myxoid variants of renal sarcomas and carcinomas, renomedullary interstitial cell tumors, and fibroepithelial polyps. It is important to recognize the existence of a renal myxoma, to avoid confusing this benign tumor with the malignant neoplasms with secondary myxoid features that may involve the kidney.     

Expression of retinoblastoma gene product (pRb) in mantle cell lymphomas. Correlation with cyclin D1 (PRAD1/CCND1) mRNA levels and proliferative activity

Mantle cell lymphomas (MCLs) are molecularly characterized by bcl-1 rearrangement and constant cyclin D1 (PRAD-1/CCND1) gene overexpression. Cyclin D1 is a G1 cyclin that participates in the control of the cell cycle progression by interacting with the retinoblastoma gene product (pRb). Inactivation of the Rb tumor suppressor gene has been implicated in the development of different types of human tumors including some high grade non-Hodgkin's lymphomas. To determine the role of the retinoblastoma gene in the pathogenesis of MCLs and its possible interaction with cyclin D1, pRb expression was examined in 23 MCLs including 17 typical and 6 blastic variants by immunohistochemistry and Western blot. Rb gene structure was studied in 13 cases by Southern blot. Cytogenetic analysis was performed in 5 cases. The results were compared with the cyclin D1 mRNA levels examined by Northern analysis, and the proliferative activity of the tumors was measured by Ki-67 growth fraction and flow cytometry. pRb was expressed in all MCLs. The expression varied from case to case (mean, 14.1% of positive cells; range, 1.3 to 42%) with a significant correlation with the proliferative activity of the tumors (mitotic index r = 0.85; Ki-67 r = 0.7; S phase = 0.73). Blastic variants showed higher numbers of pRb-positive cells (mean, 29%) than the typical cases (10%; P < 0.005) by immunohistochemistry and, concordantly, higher levels of expression by Western blot. In addition, the blastic cases also had an increased expression of the phosphorylated protein. No alterations in Rb gene structure were observed by Southern blot analysis. Cyclin D1 mRNA levels were independent of pRb expression and the proliferative activity of the tumors. These findings suggest that pRb in MCLs is normally regulated in relation to the proliferative activity of the tumors. Cyclin D1 overexpression may play a role in the maintenance of cell proliferation by overcoming the suppressive growth control of pRb.     

Mucoepidermoid carcinoma of the major salivary glands: clinical and histopathologic analysis of 234 cases with evaluation of grading criteria

BACKGROUND: The authors had previously conducted an investigation of minor salivary gland mucoepidermoid carcinoma, in which they demonstrated that certain clinical and histopathologic features were useful in predicting biologic outcome. The current study investigated the usefulness of these features in determining the prognoses of patients with mucoepidermoid carcinomas of the major salivary glands. METHODS: Clinical data and 15 histopathologic features were compared in 4 patient groups based on outcome after initial treatment. The outcome groups were 1) survival without disease, 2) survival with tumor recurrence only, 3) survival with metastasis, and 4) death related to tumor. A numeric score was assigned to each unfavorable histopathologic feature. Low grade tumors had scores of 0-4. Intermediate grade tumors scored 5 or 6. High grade tumors had scores higher than 6. RESULTS: Most patients (75%) were tumor free after the initial treatment. Twenty-one patients (9%) had local recurrence only, 12 (5%) demonstrated metastasis and survived, and 25 patients (11%) died of their disease. CONCLUSIONS: Clinical features associated with metastasis or death were more advanced age, tumor size, and preoperative symptoms. Histopathologic features that correlated with poor outcome were cystic component less than 20%, 4 or more mitotic figures per 10 high-power fields, neural involvement, necrosis, and anaplasia. All five of these histopathologic features demonstrated statistical prognostic significance when parotid gland tumors from Groups 1 and 4 were compared (P < 0.001). The point-based grading system demonstrated a statistically significant correlation with outcome for parotid tumors but not for submandibular tumors. The authors' findings indicate that patients with tumors of equal histopathologic grade have a better prognosis when their tumors are in the parotid gland than when their tumors are in the submandibular gland. Six of eight submandibular tumors that metastasized or resulted in death were low grade lesions, and none were high grade.     

Itraconazole maintenance treatment for histoplasmosis in AIDS: a prospective, multicenter trial

The expression of cytokeratins (CKs) in normal cervical epithelium, low grade squamous intraepithelial lesions (SIL), high grade SILs and squamous cell carcinoma (SCC) were analyzed using four different monoclonal antikeratin antibodies. In normal cervical epithelium, CK 18 showed strong immunoreactivity in basal and parabasal layers. CK 19 and 14 were expressed only in the basal layer while CK 13 was found selectively n the spinal cells. As the lesions progressed from low grade SIL to high grade SIL, immunoreactivity of CK 18, 19 and 14 in the basal cell compartment increased while the expression of CK 13 decreased. In SCC, as well-differentiated tumors showed decreased immunoreactivity for CK 18, 19 and 14 with CK 13 showing a strong and focal (localized) immunoreactivity. Undifferentiated carcinomas totally lacked CK 13 reactivity. Our findings therefore suggest that expression of CK 18, 19 and 14 may be directly related to tumor grade and CK 13 may be a marker of differentiation in cervical lesions.     

Subacute orbital abscess in a four-year-old girl with a new kitten

BACKGROUND: Carcinoid tumors are neoplasms of neuroendocrine origin that rarely affect the genital tract. CASE: A 75-year-old woman underwent hysterectomy and bilateral adnexectomy due to vaginal bleeding and uterine pathology (leiomyoma, cervical low grade squamous intraepithelial lesions and endometrial hyperplasia on ultrasound). Pathologic examination of the specimen disclosed a uterine corpus carcinoid tumor. The patient had been taking tamoxifen for adjuvant treatment of breast cancer diagnosed and treated seven years before. CONCLUSION: A review of the literature revealed one case of carcinoid tumor of the uterine wall. There does not appear to be any relationship between tamoxifen and the carcinoid tumors reported.     

Differential induction of tumor necrosis factor alpha in murine and human leukocytes by Mycoplasma arthritidis-derived superantigen

Mycoplasma arthritidis-derived superantigen (MAS) is exclusively produced by M. arthritidis, which is the only known mycoplasma to produce a superantigen. As a superantigen, MAS shows properties similar to those of the staphylococcal enterotoxins and related substances, such as binding to major histocompatibility complex (MHC) class II and V beta-specific stimulation of T cells. In this series of experiments, we demonstrate some differences between MAS and other superantigens. MAS induced the production of tumor necrosis factor alpha (TNF-alpha) mRNA in human as well as in murine leukocytes. However, only in murine leukocytes was the mRNA adequately translated into the protein. In human peripheral blood mononuclear cells, we found only small amounts of TNF, whereas in murine spleen cells we detected levels more than three times higher. The proliferative response to MAS has been shown to be restricted to I-E alpha in the murine MHC. Furthermore, TNF was induced in I-E alpha+ bone marrow-derived macrophages by MAS. In these cells, MAS rapidly induced very high levels of TNF and the amounts of mRNA detected correlated to the amount of protein produced. In comparison with other superantigens, including the staphylococcal enterotoxins, toxic shock syndrome toxin 1, and exfoliative toxin A, the failure of MAS to induce TNF-alpha in human peripheral blood mononuclear cells is specific for MAS and not common to all superantigens. The direct activation of bone marrow-derived macrophages also seems to be specific for MAS. These data suggest that the induction of TNF-alpha by MAS is dependent on the strength of binding to the MHC class II molecule.     

Telomerase and telomere length in the development and progression of premalignant lesions to colorectal cancer

Telomerase and telomere length are increasingly studied as prognostic markers in malignancy. Telomerase is also known to be expressed in certain nonmalignant cells, although generally at low levels. We investigated telomerase activity and telomere length in premalignant, malignant, inflammatory, and normal colon specimens to determine whether significant differences exist and whether telomerase may serve as a marker for early- or late-stage colorectal cancer. Telomerase activity was evaluated in 130 frozen specimens from human colon cancer (n = 50), adjacent normal colon tissue (n = 50), colon polyps (n = 20), and colitis (n = 10) using a modified telomeric repeat amplification protocol assay, and telomere length was assessed by terminal restriction fragment analysis. High to moderate levels of telomerase activity were detected in 90% of colorectal tumors. Weakly positive activity was detected in 10%. None of the normal tissues exhibited telomerase activity. In polyps and colitis, telomerase activity was found in 60% (12 of 20) and 40% (4 of 10), respectively. Telomerase activity in both nonmalignant lesions was 25- to 54-fold lower than that detected in colon cancer (P < 0.001). We found a positive correlation between tumor cell infiltration determined in cryostat sections and telomerase activity (r = 0.886; P > 0.0001). Late-stage tumors (Dukes C + D) demonstrated increased telomerase activity compared to early-stage tumors (Dukes A + B). Telomere restriction fragments in colon tumors had peak values of 4.8 +/- 1 kbp that were significantly and consistently shorter than those of the adjacent normal tissues (7.54 +/- 1.3 kbp), polyps (7.5 +/- 0.7 kbp), and colitis specimens (7.7 +/- 0.5kbp; P < 0.0001). Telomeres were 0.6 kbp longer in tumors with high telomerase activity and in late-stage cancers (Dukes C + D) compared to those in tumors with low telomerase activity and in early-stage cancers (Dukes A + B). Our data demonstrate that telomerase in colon cancer was commonly acquired, and activity was higher than that in polyps and colitis. However, weak telomerase activity was detected in premalignant and inflammatory lesions. Telomeres in colon cancer were considerably shorter, an indication of extensive cell proliferation and population divisions, whereas adjacent normal colon specimens, polyps, and colitis had comparable telomere lengths. Our results indicate that increased telomerase activity occurs in colon cancer cells that have undergone extensive telomere shortening relative to surrounding normal tissues and in which telomerase-induced stabilization of telomeres may be critical for the continued proliferation of the malignant clone. The link between telomerase activity and stage suggests that telomerase is up-regulated as a function of increased tumor cell invasion, tumor progression, and metastatic potential in colon cancer.