Depletion of the Transcriptional Coactivator Amplified in Breast Cancer 1 (AIB1) Uncovers Functionally Distinct Subpopulations in Triple-Negative Breast Cancer.

The transcriptional coactivator Amplified in Breast Cancer 1 (AIB1) plays a major role in the progression of hormone and HER2-dependent breast cancers but its role in triple negative breast cancer (TNBC) is undefined. Here, we report that established TNBC cell lines, as well as cells from a TNBC patient-derived xenograft (PDX) that survive chemotherapy treatment in vitro express lower levels of AIB1 protein. The surviving cell population has an impaired tube-formation phenotype when cultured onto basement membrane, a property shared with TNBC cells that survive shRNA-mediated depletion of AIB1 (AIB1LOW cells). DNA analysis by exome sequencing revealed that AIB1LOW cells represent a distinct subpopulation. Consistent with their in vitro phenotype AIB1LOW cells implanted orthotopically generated slower growing tumors with less capacity for pulmonary metastases. Gene expression analysis of cultured cells and tumors revealed that AIB1LOW cells display a distinct expression signature of genes in pro-inflammatory pathways, cell adhesion, proteolysis and tissue remodeling. Interestingly, the presence of this AIB1LOW expression signature in breast cancer specimens is associated with shorter disease free survival of chemotherapy treated patients. We concluded that TNBC cell lines contain heterogeneous populations with differential dependence on AIB1 and that the gene expression pattern of AIB1LOW cells may represent a signature indicative of poor response to chemotherapy in TNBC patients.

Reactivation of mutant p53 by a dietary-related compound phenethyl isothiocyanate inhibits tumor growth.

Mutations in the p53 tumor-suppressor gene are prevalent in human cancers. The majority of p53 mutations are missense, which can be classified into contact mutations (that directly disrupts the DNA-binding activity of p53) and structural mutations (that disrupts the conformation of p53). Both of the mutations can disable the normal wild-type (WT) p53 activities. Nevertheless, it has been amply documented that small molecules can rescue activity from mutant p53 by restoring WT tumor-suppressive functions. These compounds hold promise for cancer therapy and have now entered clinical trials. In this study, we show that cruciferous-vegetable-derived phenethyl isothiocyanate (PEITC) can reactivate p53 mutant under in vitro and in vivo conditions, revealing a new mechanism of action for a dietary-related compound. PEITC exhibits growth-inhibitory activity in cells expressing p53 mutants with preferential activity toward p53(R175), one of the most frequent 'hotspot' mutations within the p53 sequence. Mechanistic studies revealed that PEITC induces apoptosis in a p53(R175) mutant-dependent manner by restoring p53 WT conformation and transactivation functions. Accordingly, in PEITC-treated cells the reactivated p53(R175) mutant induces apoptosis by activating canonical WT p53 targets, inducing a delay in S and G2/M phase, and by phosphorylating ATM/CHK2. Interestingly, the growth-inhibitory effects of PEITC depend on the redox state of the cell. Further, PEITC treatments render the p53(R175) mutant sensitive to degradation by the proteasome and autophagy in a concentration-dependent manner. PEITC-induced reactivation of p53(R175) and its subsequent sensitivity to the degradation pathways likely contribute to its anticancer activities. We further show that dietary supplementation of PEITC is able to reactivate WT activity in vivo as well, inhibiting tumor growth in xenograft mouse model. These findings provide the first example of mutant p53 reactivation by a dietary compound and have important implications for cancer prevention and therapy.

Isolated peritoneal donor-related plasmacytoma 3 years after liver transplantation: a case report.

Organ transplantation carries a risk of disease transmission from donor to recipient, primarily infection or malignancy. Although donors are thoroughly screened, donor-related malignancies are reported to occur in 0.01% of solid organ transplants. Plasma cell neoplasm, to the best of our knowledge, has not been reported as a donor-transmitted malignancy in liver transplantation. We describe a liver transplant from a donor with unrecognized plasmacytoma requiring retransplantation. Three years after the first transplant a single peritoneal mass was detected on surveillance imaging and radically excised; HLA phenotyping confirmed the mass to be an isolated extra-medullary plasmacytoma of chimeric donor and recipient origin.

Clinicopathologic features of post-transplant lymphoproliferative disorders arising after pediatric small bowel transplant.

Few studies examined the clinicopathologic features of PTLD arising in pediatric SBT patients. Particularly, the association between ATG and PTLD in this population has not been described. Retrospective review of 81 pediatric patient charts with SBT--isolated or in combination with other organs--showed a PTLD incidence of 11%, occurring more frequently in females (median age of four yr) and with clinically advanced disease. Monomorphic PTLD was the most common histological subtype. There was a significant difference in the use of ATG between patients who developed PTLD and those who did not (p < 0.01); a similar difference was seen with the use of sirolimus (p < 0.001). These results suggested a link between the combination of ATG and sirolimus and development of more clinically and histologically advanced PTLD; however, the risk of ATG by itself was not clear. EBV viral loads were higher in patients with PTLD, and median time between detection of EBV to PTLD diagnosis was three months. However, viral loads at the time of PTLD diagnosis were most often lower than at EBV detection, thereby raising questions on the correlation between decreasing viral genomes and risk of PTLD.

Exposures in early life: associations with DNA promoter methylation in breast tumors.

There is evidence that epigenetic changes occur early in breast carcinogenesis. We hypothesized that early-life exposures associated with breast cancer would be associated with epigenetic alterations in breast tumors. In particular, we examined DNA methylation patterns in breast tumors in association with several early-life exposures in a population-based case-control study. Promoter methylation of E-cadherin, p16 and RAR-ß2 genes was assessed in archived tumor blocks from 803 cases with real-time methylation-specific PCR. Unconditional logistic regression was used for case-case comparisons of those with and without promoter methylation. We found no differences in the prevalence of DNA methylation of the individual genes by age at menarche, age at first live birth and weight at age 20. In case-case comparisons of premenopausal breast cancer, lower birth weight was associated with increased likelihood of E-cadherin promoter methylation (OR = 2.79, 95% CI, 1.15-6.82, for ⩽2.5 v. 2.6-2.9 kg); higher adult height with RAR-ß2 methylation (OR = 3.34, 95% CI, 1.19-9.39, for ⩾1.65 v. <1.60 m); and not having been breastfed with p16 methylation (OR = 2.75, 95% CI, 1.14-6.62). Among postmenopausal breast cancers, birth order was associated with increased likelihood of p16 promoter methylation. Being other than first in the birth order was inversely associated with likelihood of ⩾1 of the three genes being methylated for premenopausal breast cancers, but positively associated with methylation in postmenopausal women. These results suggest that there may be alterations in methylation associated with early-life exposures that persist into adulthood and affect breast cancer risk.

Successful isolated intestinal transplantation in sensitized recipients with the use of virtual crossmatching.

We evaluated virtual crossmatching (VXM) for organ allocation and immunologic risk reduction in sensitized isolated intestinal transplantation recipients. All isolated intestine transplants performed at our institution from 2008 to 2011 were included in this study. Allograft allocation in sensitized recipients was based on the results of a VXM, in which the donor-specific antibody (DSA) was prospectively evaluated with the use of single-antigen assays. A total of 42 isolated intestine transplants (13 pediatric and 29 adult) were performed during this time period, with a median follow-up of 20 months (6-40 months). A sensitized (PRA ≥ 20%) group (n = 15) was compared to a control (PRA < 20%) group (n = 27) to evaluate the efficacy of VXM. With the use of VXM, 80% (12/15) of the sensitized patients were transplanted with a negative or weakly positive flow-cytometry crossmatch and 86.7% (13/15) with zero or only low-titer (≤ 1:16) DSA. Outcomes were comparable between sensitized and control recipients, including 1-year freedom from rejection (53.3% and 66.7% respectively, p = 0.367), 1-year patient survival (73.3% and 88.9% respectively, p = 0.197) and 1-year graft survival (66.7% and 85.2% respectively, p = 0.167). In conclusion, a VXM strategy to optimize organ allocation enables sensitized patients to successfully undergo isolated intestinal transplantation with acceptable short-term outcomes.

Familial and racial determinants of tumour suppressor genes promoter hypermethylation in breast tissues from healthy women.

To determine the hypermethylation status of the promoter regions of tumour suppressor genes in breast tissues from healthy women and identify the determinants of these epigenetic changes. Questionnaires and breast tissues were collected from healthy women without a history of cancer and undergoing reduction mammoplasty (N= 141). Methylation for p16(INK4), BRCA1, ERalpha and RAR-beta promoter regions from breast tissues were determined by methylation specific PCR. Associations were examined with chi-square and Fisher's exact test as well as logistic regression. All statistical tests were two-sided. p16(INK4), BRCA1, ERalpha and RAR-beta hypermethylation were identified in 31%, 17%, 9% and 0% of the women, respectively. Women with BRCA1 hypermethylation had an eight-fold increase in the risk of ERalpha hypermethylation (P= 0.007). p16(INK4) hypermethylation was present in 28% of African-Americans, but 65% in European-Americans (P= 0.02). There was an increased likelihood of p16(INK4) or BRCA1 hypermethylation for women with family history of cancer (OR 2.3; 95%CI: 1.05-4.85 and OR 5.0; 95%CI: 1.55-15.81, respectively). ERalpha hypermethylation was associated with family history of breast cancer (OR 6.6; 95%CI: 1.58-27.71). After stratification by race, p16(INK4) in European-Americans and BRCA1 hypermethylation in African-Americans were associated with family history of cancer (OR 3.8; 95%CI: 1.21-12.03 and OR 6.5; 95%CI: 1.33-31.32, respectively). Gene promoter hypermethylation was commonly found in healthy breast tissues from women without cancer, indicating that these events are frequent and early lesions. Race and family history of cancer increase the likelihood of these early events.

NOD2-expressing bone marrow-derived cells appear to regulate epithelial innate immunity of the transplanted human small intestine.

BACKGROUND: Intestinal allograft rejection resembles Crohn's disease clinically and pathologically. An understanding of its mechanism could impact this life-saving procedure, as well as provide insight into the pathophysiology of inflammatory bowel disease. The NOD2 protein has been implicated as a key player in intestinal immune health, as a consequence of the discovery of three polymorphisms linked with Crohn's disease. An investigation was carried out to determine whether epithelial immune function and graft survival were influenced by NOD2 mutations in an intestinal transplant population. METHODS: The NOD2 genotypes of 34 transplants performed consecutively over the past 3 years were determined. The NOD2 genotypes were related to clinical outcomes and the expression of certain intestinal antimicrobial peptides (AMPs) believed to protect the epithelium. RESULTS: An unexpectedly high percentage of recipients, 35%, possessed NOD2 polymorphisms, while 8.6% of donors had comparable mutations. The likelihood of allograft failure was about 100-fold higher in recipients with mutant NOD2 alleles compared with recipients with wild-type NOD2 loci. Rejection in NOD2 mutant recipients was characterised by decreased expression of certain Paneth cell and enterocyte AMPs, prior to the onset of epithelial injury and inflammation. CONCLUSIONS: Crohn's disease-associated polymorphisms in the NOD2 gene in the recipient represent a critical immunological risk factor for intestinal allograft rejection. Compromised epithelial defences precede visible epithelial injury and inflammatory infiltration. The association of impaired epithelial immunity with the recipient's genotype suggests that certain NOD2-expressing cells of haematopoietic origin play a role in the process, perhaps by regulating expression of certain epithelial AMPs within the allograft.

Disruption of transforming growth factor-beta signaling through beta-spectrin ELF leads to hepatocellular cancer through cyclin D1 activation.

Transforming growth factor-beta (TGF-beta) signaling members, TGF-beta receptor type II (TBRII), Smad2, Smad4 and Smad adaptor, embryonic liver fodrin (ELF), are prominent tumor suppressors in gastrointestinal cancers. Here, we show that 40% of elf(+/-) mice spontaneously develop hepatocellular cancer (HCC) with markedly increased cyclin D1, cyclin-dependent kinase 4 (Cdk4), c-Myc and MDM2 expression. Reduced ELF but not TBRII, or Smad4 was observed in 8 of 9 human HCCs (P<0.017). ELF and TBRII are also markedly decreased in human HCC cell lines SNU-398 and SNU-475. Restoration of ELF and TBRII in SNU-398 cells markedly decreases cyclin D1 as well as hyperphosphorylated-retinoblastoma (hyperphosphorylated-pRb). Thus, we show that TGF-beta signaling and Smad adaptor ELF suppress human hepatocarcinogenesis, potentially through cyclin D1 deregulation. Loss of ELF could serve as a primary event in progression toward a fully transformed phenotype and could hold promise for new therapeutic approaches in human HCCs.

A comparison of palpable and impalpable cryptorchid testes using CD-99 immunohistochemistry.

OBJECTIVE: To compare the clinical and morphological features of impalpable and palpable cryptorchid testes, as there is debate about how much effort is appropriate to bring an impalpable undescended testicle into the scrotum. PATIENTS AND METHODS: We reviewed retrospectively 189 cases of undescended testicles in 168 patients who were explored surgically by one surgeon between August 1997 and September 2000. Operative findings of palpability, testicular size and location were collected. The mean tubular diameter (MTD), tubular fertility index (TFI) and mean number of germ cells per tubule (MGCT) were calculated using immunohistochemistry for CD-99, a Sertoli-cell marker, to classify germ cells more accurately. RESULTS: Sixty-three testes (33%) were impalpable; the median age at the time of surgical exploration was 23 months for both groups. The mean (sd) testicular volume for the impalpable and palpable groups were 0.83 (0.38) and 1.22 (0.54) mL, respectively. Using fitted curves of size vs age, impalpable testes were smaller than palpable testes at all ages, with the difference nearly statistically significant (P < 0.06). The MTD, TFI and MGCT decreased with age in both groups, with no statistically significant differences between the groups. A sub-analysis of abdominal and extra-abdominal testes confirmed no significant differences. CONCLUSION: Impalpable testes are smaller at the time of exploration than palpable cryptorchid testes. However, histological factors predict that impalpable testes have a significant chance of future fertility and therefore orchidopexy is appropriate. CD-99 immunohistochemistry makes objective morphological information easier to obtain.

Decreased expression of catenins (alpha and beta), p120 CTN, and E-cadherin cell adhesion proteins and E-cadherin gene promoter methylation in prostatic adenocarcinomas.

BACKGROUND: Catenin/E-cadherin complex proteins play an important role in cell-cell adhesion with decreased expression correlating with adverse prognostic variables in several human malignancies. METHODS: Archival formalin fixed, paraffin embedded (FFPE) sections from 118 prostatic adenocarcinomas (PACs) were immunostained by an automated method (Ventana Medical Systems, Tuscon, AZ) using monoclonal antibodies to catenins alpha and beta, p120 CTN, and E-cadherin proteins. Immunoreactivity was semiquantitatively graded, and results correlated with traditional prognostic parameters. In a subset of 10 randomly selected cases, E-cadherin gene promoter methylation status was determined on FFPE tissues using sodium bisulfite/hydroquinone DNA modification and polymerase chain reaction (PCR) with methylation specific primers (CpG wiz E-cadherin methylation assay; Intergen Co., Purchase, NY). RESULTS: Decreased expression of alpha-catenin (17%), beta catenin (4%), p120 CTN (45%), and E-cadherin (25%) proteins was noted in PACs with downregulation of each protein correlating with high tumor grade (P = 0.01-0.0001). In addition, p120 CTN and E-cadherin expression levels correlated with pathologic stage (P = 0.05; P = 0.02), aneuploidy (P = 0.001; P = 0.0001), and alpha-catenin with aneuploidy (P = 0.0001). p120 CTN loss also correlated with preoperative serum prostate specific antigen (P = 0.05). Two of 10 cases featured no evidence of E-cadherin gene promoter methylation by PCR and both cases retained expression of E-cadherin protein on immunohistochemistry. Of the 8 cases that showed E-cadherin methylation, 5 (68%) featured loss of expression of the protein on immunohistochemistry (P = 0.11). There was no correlation between E-cadherin methylation and adverse prognostic variables. CONCLUSIONS: Decreased expression of catenin/E-cadherin complex cell adhesion proteins is associated with aggressive phenotype in prostatic adenocarcinoma. E-cadherin gene promote methylation is a common event in prostate carcinoma but does not appear to bear prognostic significance in the subset of cases analyzed.

Increased expression of matrix metalloproteinases 2 and 9 and tissue inhibitors of metalloproteinases 1 and 2 correlate with poor prognostic variables in renal cell carcinoma.

PURPOSE: Matrix metalloproteinases (MMPs) degrade components of the extracellular matrix and are implicated in tissue remodeling and tumor infiltration. Tissue inhibitor of metalloproteinases (TIMPs) inhibit enzymes of the MMP family and preserve stromal integrity, thus inhibiting tumor migration. Although numerous studies on several human carcinomas have demonstrated a role for MMPs in tumor metastasis and patient survival, their prognostic role in patients with renal cell carcinoma (RCC) has not been well defined. More importantly, the recently documented paradoxical functions of TIMPs have not been characterized in these neoplasms. EXPERIMENTAL DESIGN: Five-microm, formalin-fixed, paraffin-embedded tissue sections from 153 RCCs were immunostained using specific antibodies against MMP2, MMP9, (Novocastra, Burlingame, CA) TIMP1, and TIMP2 (NeoMarkers, Fremont, CA) proteins. Immunostaining was semiquantitatively scored based on intensity and distribution, and results were correlated with histological and prognostic variables. RESULTS: The rates of increased expression of MMPs and TIMPs in RCC were as follows: MMP2, 67%; MMP9, 43%; TIMP1, 46%; and TIMP2, 73%. Each of these four markers individually correlated with histological tumor type with a vast majority of papillary and sarcomatoid RCCs expressing these proteins as compared with clear cell tumors (P range, 0.0001-0.003). Significant coexpression of MMPs and TIMPs was observed (P = 0.0001). Increased immunoreactivity for each of these proteins correlated with high tumor grade (P range, 0.0001-0.01). On univariate analysis, expression of each of these markers correlated with shortened survival (P range, 0.004-0.05). On multivariate analysis, including tumor grade, stage, and all four markers, only advanced stage (P = 0.047) and increased TIMP1 expression (P = 0.007) independently predicted shortened survival. CONCLUSION: Increased expression of MMP2, MMP9, TIMP1, and TIMP2 proteins in RCCs correlate with poor prognostic variables including shortened patient survival. The paradoxical poor prognostic implication of TIMP overexpression complements the recently documented dual function of TIMPs and warrants further investigation.

Co-downregulation of cell adhesion proteins alpha- and beta-catenins, p120CTN, E-cadherin, and CD44 in prostatic adenocarcinomas.

Cell adhesion molecule expression has been linked to disease outcome in prostatic adenocarcinomas (PACs). We evaluated the coordinated expression of catenin-related proteins, E-cadherin, N-cadherin, and CD44s in PACs. Archival sections from 112 PACs were immunostained by an automated method (Ventana Medical Systems, Tucson, AZ) using monoclonal antibodies to alpha- and beta-catenins, p120CTN, E-cadherin, N-cadherin, and CD44s proteins. Immunoreactivity was semiquantitatively scored, and results were evaluated for association between these markers. Staining results were also correlated with tumor grade, stage, ploidy, preoperative serum PSA, and postoperative biochemical disease recurrence. Decreased expression of alpha- and beta- catenins, p120CTN, E-cadherin, and CD44s proteins (range, 5% to 49%) was noted in PACs, and downregulation of each of these proteins correlated with high tumor grade (P =.02 to.0001). Although loss of E-cadherin and p120CTN each correlated with stage (E-cadherin, P =.02; p120CTN, P =.02) and ploidy (E-cadherin, P =.0001; p120CTN, P =.004), downregulation of CD44s correlated with ploidy (P =.002), serum PSA (P =.005), and postoperative disease recurrence (P =.02). N-cadherin was positive in only 5% of PACs and did not correlate with any prognostic parameters. alpha-Catenin downregulation correlated with decreased expression of E-cadherin (P =.0001). Additionally, decreased expression of each of these 2 proteins respectively correlated with loss of beta-catenin (P =.0001 and.004), p120CTN (P =.005 and.001), and CD44s (P =.008 and.01). beta-Catenin expression levels correlated with p120CTN (P =.01). A trend for co-downregulation of CD44s and p120CTN and of CD44s and beta-catenin was observed. In conclusion, the significant association between decreased expression of various members of the CAM family of proteins supports their collective role in mediating cell-cell adhesion. Altered expression of these proteins may be of prognostic value in patients with prostate cancer.

Xenogeneic extracellular matrix grafts elicit a TH2-restricted immune response.

BACKGROUND: Porcine small intestinal submucosa (SIS) is an acellular, naturally derived extracellular matrix (ECM) that has been used for tissue remodeling and repair in numerous xenotransplantations. Although a vigorous immune response to xenogeneic extracellular matrix biomaterials is expected, to date there has been evidence for only normal tissue regeneration without any accompanying rejection. The purpose of this study was to determine the reason for a lack of rejection. METHODS: Mice were implanted s.c. with xenogeneic tissue, syngeneic tissue, or SIS, and the graft site analyzed histologically for rejection or acceptance. Additionally, graft site cytokine levels were determined by reverse transcriptase polymerase chain reaction and SIS-specific serum antibody isotype levels were determined by ELISA. RESULTS: Xenogeneically implanted mice showed an acute inflammatory response followed by chronic inflammation and ultimately graft necrosis, consistent with rejection. Syngeneically or SIS implanted mice, however, showed an acute inflammatory response that diminished such that the graft ultimately became indistinguishable from native tissue, observations that are consistent with graft acceptance. Graft site cytokine analysis showed an increase in interleukin-4 and an absence of interferon-gamma. In addition, mice implanted with SIS produced a SIS-specific antibody response that was restricted to the IgG1 isotype. Reimplantation of SIS into mice led to a secondary anti-SIS antibody response that was still restricted to IgG1. Similar results were observed with porcine submucosa derived from urinary bladder. To determine if the observed immune responses were T cell dependent, T cell KO mice were implanted with SIS. These mice expressed neither interleukin-4 at the implant site nor anti-SIS-specific serum antibodies but they did accept the SIS graft. CONCLUSIONS: Porcine extracellular matrix elicits an immune response that is predominately Th2-like, consistent with a remodeling reaction rather than rejection.

Decreased CD44 standard form expression correlates with prognostic variables in ovarian carcinomas.

Expression of CD44 standard form (CD44s) was evaluated by automated immunohistochemical analysis using the anti-CD44 A3D8 clone in 101 ovarian epithelial neoplasms including 82 primary tumors (64 carcinomas and 18 tumors of low malignant potential [LMP]), 9 lymph node metastases, 8 malignant ascites, and 2 peritoneal implants. Immunostaining was scored semiquantitatively. Tumors were graded according to the FIGO (International Federation of Gynecology and Obstetrics) classification system. Tumor stage and patient survival were determined from the patient records. While 9 of 18 LMP tumors expressed CD44s, only 15 of 64 carcinomas expressed it. In the carcinomas, univariate analysis revealed that decreased CD44s expression correlated with high tumor grade, advanced stage, and shortened survival. Loss of CD44s expression also was noted in the tumor cells in 8 of 9 lymph node metastases, 7 of 8 malignant ascites, and 1 of 2 implants. Multivariate analysis revealed that only tumor stage independently correlated with patient survival. Loss of CD44s expression determined by immunohistochemical analysis is more common in ovarian carcinomas than in LMP tumors; correlates with prognostic variables including tumor grade, stage, and survival; and may have an important role in the dissemination of ovarian cancer.

Molecular pathology of leukemia and lymphoma.

Molecular dissection of physiologic and pathologic genetic phenomena in hematologic malignancy has provided the pathologist with a broad menu of new assays. By integrating the data gleaned from these techniques we can formulate more rational and biologically based diagnoses, which should lead to the ultimate goal of targeted therapy for these specific entities. We summarize some of the more relevant molecular genetic assays and present an overview of those genetic mechanisms usually evaluated in the current practice of hematopathology. The usefulness of such assays extends beyond refining diagnoses in that they also provide relevant prognostic information. Moreover, since most are based on the polymerase chain reaction and reverse transcriptase polymerase chain reaction, we are more sensitively able to monitor for residual disease after attempts at curative therapy, and our definition of remission has been dramatically altered. However, molecular genetic tests are not without limitations, and we must remain cognizant of their cost effectiveness and be aware of current deficiencies in standardization. The challenge will be to meaningfully and economically harness and integrate the information we obtain from these and future technologies into appropriate clinical practice.

Posttherapy surveillance of B-cell precursor acute lymphoblastic leukemia. Value of polymerase chain reaction and limitations of flow cytometry.

Flow cytometric immunophenotypic analysis is critical in diagnosis and classification of acute leukemia and has been used after therapy to monitor for minimal residual disease. However, the presence of normal B-cell precursors, hematogones, particularly in the context of treated pediatric B-cell precursor acute lymphoblastic leukemia (BP-ALL), may confound such evaluation. In this study, the value of more specific genotypic markers (polymerase chain reaction evaluation of 2 antigen receptor genes) was assessed to resolve this issue. Flow cytometric analysis of enriched mononuclear cells revealed 1% to 20% precursor B cells (PBCs), based on expression of 1 or more pan-B cell antigens in addition to CD10, CD34, and terminal deoxynucleotidyl transferase in all 14 patients studied. Inasmuch as this mimicked the immunophenotype of the original leukemic clone, PBCs, in isolation, were considered suspicious for minimal residual disease. However, 11 of the 14 posttherapy specimens (79%) revealed no monoclonally rearranged antigen receptor genes, and 7 of these 11 patients had trackable genotypic markers at presentation. Accordingly, by PCR these 7 patients had complete molecular remission, supported by clinical follow up of 16 to 73 months. Among the remaining 4 patients with PCR-negative disease, 3 continue in remission, confirming the interpretation of false-positive flow cytometric analysis. In conclusion, flow cytometric monitoring of posttherapy bone marrow specimens from patients with BP-ALL may be misleading, if considered in isolation, in falsely suggesting the presence of minimal residual disease. Rather, PCR for antigen receptor gene rearrangements is a valuable and specific tool, helpful in differentiating hematogones from minimal residual disease in patients with treated BP-ALL whose bone marrow harbors increased PBCs.

The prognostic significance of proliferation-associated nucleolar protein p120 expression in prostate adenocarcinoma: a comparison with cyclins A and B1, Ki-67, proliferating cell nuclear antigen, and p34cdc2.

BACKGROUND: In this study, the authors evaluated the prognostic significance of the expression of nucleolar antigen p120, along with other cell proliferation-associated proteins, in prostate adenocarcinomas (PACs) and compared the results with previously reported data on p34cdc2 cyclin-dependent kinase (p34 cdk). METHODS: Archival sections from 132 PACs were immunostained with monoclonal antibodies against p120, cyclin A, cyclin B1, Ki-67, and proliferating cell nuclear antigen (PCNA). The DNA content of each tumor was determined by the Feulgen method using image analysis. The immunohistochemistry (IHC) results were correlated with tumor grade, stage, margin positivity, metastasis, ploidy, and postsurgical disease recurrence. RESULTS: The overall positivity for the various proteins follows: p120, 36%; cyclin A, 35%; cyclin B1, 43%; Ki-67, 46%; and PCNA, 32%. p120 correlated with grade (P = 0.004), stage (P = 0.01), ploidy (P = 0.02), margin positivity (P = 0.03), and metastasis (P = 0.004). Cyclin B1 correlated with ploidy (P = 0.04) and grade (P = 0.05), Ki-67 with grade (P = 0.02) and margins (P = 0.03), and PCNA with grade (P = 0.01). Significant coexpression among these proteins was noted, as was a significant association between the expression of these markers and that previously reported for p34 cdk. In univariate analysis, p120 (P = 0.01), cyclin A (P = 0.01) and p34 cdk (P = 0.002) correlated with disease recurrence. In multivariate analysis of all these proteins, only p34 cdk independently predicted postsurgical recurrence (P = 0.05). CONCLUSIONS: Nucleolar antigen p120 expression appears to be an additional marker of aggressiveness in PACs. The significant coexpression of the various cell cycle regulatory proteins support their collective role in tumor cell proliferation, with p34 cdk positivity being an independent predictor of postsurgical recurrence.

HER-2/neu oncogene amplification by fluorescence in situ hybridization in epithelial tumors of the ovary.

HER-2/neu gene amplification and protein overexpression have been associated with prognosis in breast, lung and prostate cancers but have not been extensively studied in ovarian carcinoma. For the study, we selected 5-micron-thick, formalin-fixed, paraffin-embedded tissue sections from 74 cases of ovarian epithelial tumors of low malignant potential and ovarian carcinoma. Tumors were graded and staged and evaluated for amplification of the HER-2/neu gene by fluorescence in situ hybridization. HER-2/neu amplifications was present in 3 of 13 serous, mucinous, and endometrioid epithelial tumors of low malignant potential and in 40 of 61 epithelial carcinomas. In the carcinoma group, amplification did not correlate with stage, grade, or tumor type. Mean follow-up was 31 months; 1 patient with a low malignant potential tumor and 32 patients with carcinomas died of disease. On univariate and multivariate analysis, survival correlated with stage of disease but not with HER-2/neu amplification. HER-2/neu amplification by fluorescence in situ hybridization can be performed on tissue sections of ovarian neoplasms; amplification is uncommon in ovarian tumors of low malignant potential, but is present in 66% of ovarian epithelial carcinomas. HER-2/neu amplification did not predict outcome in ovarian epithelial neoplasia but may have an important role in tumor development.