Methylation and protein expression of DNA repair genes: association with chemotherapy exposure and survival in sporadic ovarian and peritoneal carcinomas

Background

DNA repair genes critically regulate the cellular response to chemotherapy and epigenetic regulation of these genes may be influenced by chemotherapy exposure. Restoration of BRCA1 and BRCA2 mediates resistance to platinum chemotherapy in recurrent BRCA1 and BRCA2 mutated hereditary ovarian carcinomas. We evaluated BRCA1, BRCA2, and MLH1 protein expression in 115 sporadic primary ovarian carcinomas, of which 31 had paired recurrent neoplasms collected after chemotherapy. Additionally, we assessed whether promoter methylation of BRCA1, MLH1 or FANCF influenced response to chemotherapy or explained alterations in protein expression after chemotherapy exposure.

Results

Of 115 primary sporadic ovarian carcinomas, 39 (34%) had low BRCA1 protein and 49 (42%) had low BRCA2 expression. BRCA1 and BRCA2 protein expression were highly concordant (p < 0.0001). MLH1 protein loss occurred in 28/115 (24%) primary neoplasms. BRCA1 protein loss in primary neoplasms was associated with better survival (p = 0.02 Log Rank test) and remained significant after accounting for either stage or age in a multivariate model (p = 0.04, Cox proportional hazards). In paired specimens, BRCA1 protein expression increased in 13/21 (62%) and BRCA2 protein expression increased in 15/21 (71%) of recurrent carcinomas with low or intermediate protein in the paired primary. In contrast MLH1 expression was rarely decreased in recurrent carcinomas (1/33, 3%). Similar frequencies of MLH1, BRCA1, and FANCF promoter methylation occurred in primary carcinomas without previous chemotherapy, after neoadjuvant chemotherapy, or in recurrent neoplasms.

Conclusion

Low BRCA1 expression in primary sporadic ovarian carcinoma is associated with prolonged survival. Recurrent ovarian carcinomas commonly have increased BRCA1 and/or BRCA2 protein expression post chemotherapy exposure which could mediate resistance to platinum based therapies. However, alterations in expression of these proteins after chemotherapy are not commonly mediated by promoter methylation, and other regulatory mechanisms are likely to contribute to these alterations.

Intratumoral T cells, tumor-associated macrophages, and regulatory T cells: association with p53 mutations, circulating tumor DNA and survival in women with ovarian cancer

OBJECTIVES

Forty percent of women with ovarian cancer have circulating free tumor DNA. We sought to determine if the tumor immune infiltrate varied based on tumor p53 mutation status or presence of circulating tumor DNA.

METHODS

We performed immunohistochemistry on 119 ovarian cancer specimens with CD3 and CD8 (Intratumoral T cells (TILs)), CD68 (tumor-associated macrophages (TAMs)), and FoxP3 (T regulatory cells (Tregs)). Tumors had been previously sequenced for mutations in exons 4-10 of p53, and plasma from women characterized for free tumor DNA.

RESULTS

TIL and TAM levels were positively correlated (P<0.0001). High levels of TILs were identified in 54 of 119 tumors (45.4%). No survival difference was identified according to the presence of TILs or TAMs. Patients with greater TILs were more likely to be optimally cytoreduced (P=0.005). p53 mutations were associated with more TILs (P=0.008). The presence of circulating tumor DNA did not correlate with TILs, TAMs, or Tregs. In the subgroup with a low host antitumor immune response, the intermediate response Tregs group did have a survival advantage (P=0.049).

CONCLUSIONS

p53 mutations are associated with higher levels of TILs. The ratio of Tregs to TILS may be more important than absolute levels. A brisk T cell response within the tumor predicts adequacy of cytoreduction, suggesting successful cytoreduction may be partially due to underlying tumor biology and host response.

Defining an appropriate threshold for the diagnosis of serous borderline tumor of the ovary: when is a full staging procedure unnecessary?

How much borderline change in an otherwise typical ovarian serous cystadenoma should warrant classification as a serous ovarian "borderline tumor?" We correlated estimated volume and percent borderline change with stage in 56 cases of serous ovarian neoplasms (excluding carcinomas) diagnosed as at least focal borderline change to see if we could define an appropriate threshold for the diagnosis of borderline tumor that would justify full surgical staging. Forty-three cases were completely staged, 6 had "fertility-sparing" but otherwise complete staging, and 7 cases had "limited" staging. Thirty-eight cases were stage 1a-1c, and 18 were greater than stage 1. Cases with stage 1 disease had a significantly lower mean volume of borderline change sampled of 2.0 compared with 5.6 cm in cases with greater than stage 1 disease (P = 0.0002). All high-stage cases had at least 1.0 cm or more of borderline change sampled (range, 1.0-12). Cases with stage 1 disease had a significantly lower mean estimated total percent borderline change of 34.8% compared with 77.2% in cases with greater than stage 1 disease (P < 0.0001). All high-stage cases had 20% or more total borderline change (range, 20%-100%). In addition, a grossly exophytic growth pattern component was highly predictive of high stage (P < or = 0.0001). Two cases recurred-both were advanced-stage and high-percent borderline change. There were no deaths due to disease (mean follow-up, 85 months). Our study supports a conservative 10% cutoff for classification as a "borderline tumor," and that complete surgical staging is not necessary when a serous neoplasm with an intracystic growth pattern has less than 10% or 0.5-cm borderline change.

Functional characterization of a novel BRCA1-null ovarian cancer cell line in response to ionizing radiation

The breast and ovarian cancer susceptibility gene BRCA1 plays a major role in the DNA damage response pathway. The lack of well-characterized human BRCA1-null cell lines has limited the investigation of BRCA1 function, particularly with regard to its role in ovarian cancer. We propagated a novel BRCA1-null human ovarian cancer cell line UWB1.289 from a tumor of papillary serous histology, the most common form of ovarian carcinoma. UWB1.289 carries a germline BRCA1 mutation within exon 11 and has a deletion of the wild-type allele. UWB1.289 is estrogen and progesterone receptor negative and has an acquired somatic mutation in p53, similar to the commonly used BRCA1-null breast cancer cell line HCC1937. We used ionizing radiation to induce DNA damage in both UWB1.289 and in a stable UWB1.289 line in which wild-type BRCA1 was restored. We examined several responses to DNA damage in these cell lines, including sensitivity to radiation, cell cycle checkpoint function, and changes in gene expression using microarray analysis. We observed that UWB1.289 is sensitive to ionizing radiation and lacks cell cycle checkpoint functions that are a normal part of the DNA damage response. Restoration of wild-type BRCA1 function in these cells partially restores DNA damage responses. Expression array analysis not only supports this partial functional correction but also reveals interesting new information regarding BRCA1-positive regulation of the expression of claudin 6 and other metastasis-associated genes and negative regulation of multiple IFN-inducible genes.

Alternate molecular genetic pathways in ovarian carcinomas of common histological types

We evaluated alterations in p53, PIK3CA, PTEN, CTNNB1 (beta-catenin), MLH1, and BRAF among common histological subsets of epithelial ovarian tumors to characterize patterns of alterations of different molecular pathways. There were 12 clear cell, 26 endometrioid, and 51 serous carcinomas evaluated by direct DNA sequencing for mutations in p53, PIK3CA, PTEN, BRAF, and CTNNB1. Methylation-specific polymerase chain reaction (PCR) assessed MLH1 promoter methylation status. Quantitative PCR identified PIK3CA amplification in 22 EC/CC and 94 SC. p53 mutations were identified in 25 (49%) of 51 SC, 11 (42%) of 26 EC, and 1 (8.3%) of 12 CC neoplasms and were more common in grade 3 EC (P = .045) and advanced-stage EC/CC (P = .007). PIK3CA mutations were identified in 3 (25%) of 12 CC, 3 (12%) of 26 EC, and 0 of 51 SC. PTEN mutations were significantly more common in EC (8/26, 31%) compared with CC (0/12; P = .04) and SC (2/51, 4%; P = .002). CTNNB1 mutations were identified, 6 (23%) EC and no CC or SC (P = .008). Both PTEN and CTNNB1 mutations were more common in low-grade EC/CC, whereas PIK3CA mutations occurred only in grade 3 cancers. PTEN and PIK3CA mutations were more common in p53 wild-type tumors (P = .003). PIK3CA amplification occurred in fewer EC/CC (0/22) versus SC (19/94, 20%; P = 0.02) and were slightly more common in p53 wild-type compared with p53 mutant SC (P = .08). Of 26 EC, 22 (85%) had a mutation in one of the genes studied compared with 4 33% of 12 CC (P = .003). Women with EC/CC had significantly better overall survival (P = .0008), and this remained significant after accounting for stage (P=.04). Mutations in p53 or in PTEN/PIK3CA are alternative pathways in ovarian carcinogenesis. Activation of PIK3CA occurs by gene amplification in SC but via somatic mutation of PIK3CA or PTEN in EC and CC. PIK3CA mutations are associated with high-grade tumors, whereas PTEN and CTNNB1 mutations are associated with low-grade tumors. Mutations in p53, PIK3CA, PTEN, and CTNNB1 account for most EC tumors; most CC remain unexplained. EC/CC histology is a favorable prognostic factor.

Epithelioid trophoblastic tumor: review of a rare neoplasm of the chorionic-type intermediate trophoblast

We present a brief review of epithelioid trophoblastic tumor, a rare trophoblastic neoplasm derived from chorionic-type intermediate trophoblastic cells that typically presents in reproductive-age women between 1 and 18 years following a previous gestation. Histologic features include a nodular growth pattern of monomorphic, epithelioid cells within a hyaline matrix. Areas of necrosis and mitotic activity (0-9 mitoses per 10 high-power fields) are additional features of this neoplasm. Positive immunostaining for p63 and cytokeratin, frequent location in the lower uterine segment and endocervix, as well as the epithelioid appearance can lead to confusion with squamous cell carcinoma. Inhibin-alpha is typically expressed, as well as focal, more variable expression of other trophoblastic markers including beta-human chorionic gonadotropin, human placental lactogen, placental alkaline phosphate, and Mel-CAM (CD148). The clinical behavior of this rare form of gestational trophoblastic disease is difficult to predict. Although most cases follow a benign course following resection, there is a potential for metastatic disease.

Predictors of occult neoplasia in women undergoing risk-reducing salpingo-oophorectomy

OBJECTIVE

The purpose of this study was to define the rate of neoplasia in prophylactic surgical specimens with the use of a careful surgical and pathologic protocol in a prospective study of high-risk women who were undergoing risk-reducing salpingo-oophorectomy. Outcomes of interest were neoplasia that was identified in surgical specimens and clinical outcomes of women who were undergoing risk-reducing salpingo-oophorectomy. We hypothesized that older age and having a BRCA1 mutation would be predictors for tubal or ovarian neoplasia and that a careful surgical and pathologic protocol would lead to a low rate of subsequent primary peritoneal cancer.

STUDY DESIGN

A prospective tissue and research database enrolled patients who underwent risk-reducing salpingo-oophorectomy for prevention of ovarian cancer. Clinical and pathologic data were extracted for those patients after the initiation of a defined surgical and pathologic protocol in 1999.

RESULTS

One hundred thirteen women met the high-risk criteria; 40 of the women (45%) who were tested had a deleterious mutation in BRCA1, and 22 women (25%) had a mutation in BRCA2. Seven women had ovarian or tubal neoplasia (6.2%). One woman had occult endometrial cancer. Age > or =45 years and having a BRCA1 or BRCA2 mutation were significant predictors of occult neoplasia. Two patients with neoplasia that was identified at risk-reducing salpingo-oophorectomy experienced recurrence. Three patients with BRCA1 mutations have subsequent new diagnoses of breast cancer. No patients had primary peritoneal cancer after risk-reducing salpingo-oophorectomy.

CONCLUSION

Age > or =45 years and mutations in BRCA1 or BRCA2 predict occult neoplasia in women who undergo risk-reducing salpingo-oophorectomy. A thorough pathologic and surgical protocol at the time of risk-reducing salpingo-oophorectomy may improve the risk of subsequent primary peritoneal cancer.

Unexpected gynecologic neoplasms in patients with proven or suspected BRCA-1 or -2 mutations: implications for gross examination, cytology, and clinical follow-up

Identification of inheritable mutations associated with the development of malignancy has led to prophylactic surgeries to remove tissues at risk. We report seven unrelated patients with family histories of breast and/or ovarian cancer, five of whom underwent prophylactic salpingo-oophorectomy with hysterectomy. Four had proven BRCA-1 or -2 mutations. Malignant cells were found unexpectedly in the peritoneal washings of two patients, leading to the discovery of early-stage fallopian tube carcinoma. After changing the sampling technique at our institution, two more cases of unexpected fallopian tube carcinoma in situ were discovered. Another patient had a significant family history and underwent hysterectomy for uterine fibroids, leading to the discovery of fallopian tube carcinoma. Another patient with BRCA-1 mutation had unexpected widespread primary peritoneal papillary serous adenocarcinoma. The final patient had a borderline malignant clear cell adenofibroma. These cases underscore the importance of peritoneal cytology and thorough sampling in the management of patients undergoing hysterectomy with a family history of breast/ovarian cancer and/or known BRCA-1/BRCA-2 mutations. As prophylactic surgeries are becoming more common secondary to advances in molecular diagnostics, pathologists need to be aware that surgical specimens from these patients may require more rigorous examination to uncover early neoplastic changes.

Occult cancer of the fallopian tube in BRCA-1 germline mutation carriers at prophylactic oophorectomy: a case for recommending hysterectomy at surgical prophylaxis

OBJECTIVE

BRCA-1 and BRCA-2 germline mutations increase the risk of ovarian and breast cancer. Primary cancer of the fallopian tube is rare; however, recent evidence suggests that patients harboring a germline mutation conferring an increased risk of ovarian cancer may be at risk for fallopian tube cancer as well. We discuss the finding of occult fallopian tube cancer diagnosed at surgical prophylaxis in women harboring BRCA-1 mutations.

METHODS/RESULTS

Two patients undergoing surgical prophylaxis to address an increase in ovarian cancer risk were discovered to harbor occult primary fallopian tube carcinoma on final pathology review. Mutational analysis confirmed the presence of a deleterious mutation in BRCA-1 in both patients.

CONCLUSION

Currently, consensus opinions regarding ovarian cancer surgical prophylaxis in gene mutation carriers do not include hysterectomy as part of the preventative procedure. This report as well as a growing number of cases of fallopian tube cancer reported in known BRCA-1 and BRCA-2 mutation carriers has important implications for recommendations regarding surgical prophylaxis in these women.

Spindle cell lipoma of the oral cavity. Report of a rare intramuscular case with fine needle aspiration findings

BACKGROUND

Spindle cell lipoma (SCL) is a benign neoplasm characterized by a mixture of mature fat, bland spindle cells and wiry collagen in a variably myxoid background. Oral SCLs are rare, and only four cases of intramuscular SCL exist in the literature. We report the first case of intramuscular SCL of the oral cavity with fine needle aspiration (FNA) findings.

CASE

A 61-year-old woman presented with a 3-cm mass in the right gingivobuccal sulcus. Papanicolaoustained FNA smears were hypocellular and contained loose collections of spindle cells in a myxoid background, numerous mast cells, rare capillary fragments and portions of skeletal muscle. The spindle cells had mild nuclear enlargement, focal nuclear irregularities, rare intranuclear inclusions and occasional small nucleoli. No lipoblasts or mitoses were identified. There was intermingling of the spindle cells with the skeletal muscle fragments.

CONCLUSION

Intraoral SCL is a rare lesion but should be considered in the differential for a benign spindle cell neoplasm in the oral cavity. Clues to diagnosis on cytology include mature fat, bland spindle cells, a myxoid background and mast cells.

Differential expression of mammalian TRP homologues across tissues and cell lines

Mammalian homologues of the Drosophila trp gene have been invoked as the structural basis for the currents associated with capacitative Ca2+ entry (CCE) in many cell types. Trp homologues are members of a large protein family that may associate as channel subunits providing an explanation for the functional diversity of store-operated channels observed in these cells. However, there is little information as to which of these genes are co-expressed at the cellular level. We have examined the tissue specific expression of five mammalian trp genes and determined which are co-expressed in five different cell lines. The results show tissue- and cell-specific co-expression of multiple trp forms. This implies that the subunit composition of a particular CCE channel may vary depending on the cell type.

Concomitant and hormonally regulated expression of trp genes in bovine aortic endothelial cells

Recent findings have suggested that the vertebrate trp family of channel proteins is the structural basis for Ca2+ influx through the capacitative calcium entry (CCE) pathway. We have discerned, in bovine aortic endothelial cells, the concomitant expression of four such vertebrate genes: trp-1 (two splice variants), trp-3, trp-4 and trp-5. Exogenous hormones rendered dynamic effects on the transcript levels of these genes. Most notably, beta-estradiol significantly down-regulated trp-4 while trans-retinoic acid dramatically up-regulated trp-5; yet these hormones rendered little change in CCE. These findings suggest that the extent of a given trp channel's participation in CCE is not reflected in alterations of its transcript level.

Expression of neurotrophin-3 in the growing velvet antler of the red deer Cervus elaphus

Antlers are organs of bone which regenerate each year from the heads of male deer. In addition to bone, support tissues such as nerves also regenerate. Nerves must grow at up to 1 cm/day. The control of this rapid growth of nerves is unknown. We examined the relative expression of neurotrophin-3 (NT-3) mRNA in the different tissues of the growing antler tip and along the epidermal/dermal layer of the antler shaft of the red deer Cervus elaphus, using semi-quantitative reverse transcription-polymerase chain reaction. Expression in the tip was found to be highest in the epidermal/dermal layer and lowest in the cartilaginous layer in all developmental stages examined. These data correlate well with the density and pattern of innervation of these tissues. Along the epidermal/dermal layer of the antler shaft, expression was highest in the segments subjacent to the tip and lowest near the base, arguing for differences in the temporal expression of NT-3 in these segments. The expression of NT-3 in cells isolated from the different layers of 60-day antlers did not mirror that observed when whole tissues were used and may suggest regional specificity of NT-3 expression within antler tissues.

The structure, sequence and developmental pattern of expression of the white gene in the blowfly Lucilia cuprina

We have sequenced the complete coding region of the white gene of Lucilia cuprina. Strong sequence identity exists between this gene and its homologue from Drosophila melanogaster at both nucleotide and derived amino acid levels (68% and 78% respectively). The exon/intron structure of the two genes is also largely conserved, although the Lucilia gene contains one extra intron. Expression of the gene peaks during mid-pupal stage, with secondary peaks in late larval and early adult stages. Comparisons between this and other white genes will contribute to a better understanding of ATP-binding transmembrane transport proteins. The white gene should also serve as a useful marker gene in the development of a gene transformation system for the sheep blowfly.

Prostatic intraepithelial neoplasia: significance and management

Prostatic intraepthelial neoplasia (PIN) is a putative premalignant change that bears a morphological similarity to prostatic cancer and shows increased frequency, severity, and extent in patients with prostate cancer. This article discusses the evidence for PIN as a premalignant lesion, reviews the morphology, terminology, appropriate grading system, and diagnostic significance of PIN, as well as describes management recommendations for further evaluation when PIN is diagnosed in prostate resection and biopsy specimens. Clinical management of high-grade PIN found in transurethral resection of the prostate (TURP) or prostate biopsy specimens should include repeat transrectal ultrasound (TRUS) and prostate biopsy for early detection of prevalent coexistent prostate cancer. In cases of high-grade PIN, increased surveillance methods have the potential to decrease morbidity and mortality by early cancer diagnosis.

Distribution of Leu-7 antigen (HNK-1) in thyroid tumors: Its usefulness as a diagnostic marker for follicular and papillary carcinomas

The reactivity of the anti-Leu-7 monoclonal antibody was tested in 39 neoplastic and nonneoplastic thyroid tissue specimens. These included eight colloid goiters, 14 follicular adenomas, nine papillary carcinomas, five follicular carcinomas, two medullary carcinomas, and one metastatic follicular carcinoma in bone. We observed strong cytoplasmic and/or cell membrane positivity in all follicular and papillary carcinomas, in both primary and metastatic tumors. However, the medullary thyroid carcinomas tested were negative. We also observed weak and only occasional staining with anti-Leu-7 antibody in colloid goiter and follicular adenomas. The staining in the benign thyroid lesions was usually focal, less than 10% of the cells; however, in cases of follicular and papillary carcinomas, both in primary and metastatic tumors, the staining was diffuse and strong. Some of the colloid material in colloid goiters and follicular adenomas showed faint homogenous staining with anti-Leu-7 antibody. Our findings suggest that anti-Leu-7 monoclonal antibody is a marker that may facilitate the differentiation between benign and malignant thyroid lesions, with the exception of medullary carcinoma. In addition, caution should be taken when using this antibody to diagnose metastatic lesions, as other metastatic carcinomas have also been reported to be positive. This antibody should be used in conjunction with a panel of antisera to complement a morphologic diagnosis.

Platelets mediate glomerular cell proliferation in immune complex nephritis induced by anti-mesangial cell antibodies in the rat

We investigated whether platelets, which are rich in growth factors, could mediate glomerular cell proliferation in immune complex glomerulonephritis (GN) in the rat induced with an antibody directed against the Thy-1 antigen present on mesangial cells. Rats were depleted of platelets (mean platelet count less than 20,000/mm3) with goat anti-rat platelet IgG before induction of GN and platelet depletion was maintained for 48 hours. At 72 hours sections were immunostained for cyclin, an S-phase-related nuclear antigen, to identify proliferating cells, and for the common leukocyte antigen (CD45) to identify infiltrating leukocytes. Platelet depleted rats had fewer proliferating resident glomerular cells (CD45-, cyclin+) compared to controls (0.8 +/- 0.5 vs. 2.8 +/- 1.4 cells/glom cross section, P less than 0.01) and better renal function (creatinine 1.07 +/- 0.12 vs. 1.27 +/- 0.15 mg/dl, P less than 0.05). These effects were not due to changes in circulating or glomerular leukocyte counts, complement, or glomerular antibody binding. These studies provide the first direct evidence that platelets mediate glomerular (probably mesangial cell) proliferation in antibody-mediated GN.

Analysis of proliferative grade using anti-PCNA/cyclin monoclonal antibodies in fixed, embedded tissues. Comparison with flow cytometric analysis

Cell kinetic information is an important adjunct to histologically-based tumor classifications. Presently, cell kinetic data can be obtained from slide-based material only with monoclonal antibodies such as Ki-67, which require the use of frozen sections and cannot be applied to archival, paraffin-embedded material. Monoclonal antibodies have recently been generated to PCNA/cyclin, a 36 kd, S-phase-associated nuclear protein. The authors investigated whether monoclonal antibody 19A2 could be used to identify proliferating cells within fixed, embedded tissue sections. Deparaffinized sections of 41 methacarn-fixed human tumors were immunostained with 19A2 using a streptavidin biotin immunoperoxidase system. A semiquantitative scoring system was used to evaluate the fraction of cells that were PCNA/cyclin-positive, and this score was compared with cell kinetic data obtained from parallel flow cytometric S-phase analysis that had been performed on fresh samples of the same tumors. While there was general agreement between the slide-based, antibody-derived and the flow cytometrically-derived cell kinetic information, some discrepancies were observed. Some of the latter represented cases in which the anti-PCNA/cyclin antibody preparations demonstrated significant heterogeneity in the numbers of proliferating cells in different regions of the tumor. In other cases, a significant fraction of the positive cells corresponded to nontumor stromal and/or inflammatory cells. In these cases, the slide-based method provided more information about the tumor cell population than did the flow cytometry data. It is concluded that semiquantitative immunocytochemical analysis with anti-PCNA/cyclin antibodies may represent a simple, reproducible, yet powerful technique for the routine analysis of cell kinetic data in alcohol-fixed, paraffin-embedded tissue by the surgical pathologist.

Intraspinal primitive neuroectodermal tumor arising from the sacral spinal nerve root

An unusual case of intraspinal primitive neuroectodermal tumor arising from the sacral spinal nerve root is presented with the first documentation of myelographic, computed tomographic, and magnetic resonance imaging findings.