Primary follicular lymphoma of an extraordinarily large prostate: A case report and review of the literature

Primary follicular lymphoma of the prostate is rare. This case report and literature review literature describes a 74-year old male patient who presented with worsening urinary symptoms, and imaging showing prostatomegaly compressing and displacing the rectum. He ultimately underwent a Millen retropubic prostatectomy for a prostate of 692 cc. The histology and immunohistochemistry confirmed the diagnosis as follicular lymphoma. His lymphoma underwent high-grade transformation with leptomeningeal involvement.

Multiparameter immunohistochemistry analysis of HIV DNA, RNA and immune checkpoints in lymph node tissue

The main barrier to a cure for HIV is the persistence of long-lived and proliferating latently infected CD4+ T-cells despite antiretroviral therapy (ART). Latency is well characterized in multiple CD4+ T-cell subsets, however, the contribution of regulatory T-cells (Tregs) expressing FoxP3 as well as immune checkpoints (ICs) PD-1 and CTLA-4 as targets for productive and latent HIV infection in people living with HIV on suppressive ART is less well defined. We used multiplex detection of HIV DNA and RNA with immunohistochemistry (mIHC) on formalin-fixed paraffin embedded (FFPE) cells to simultaneously detect HIV RNA and DNA and cellular markers. HIV DNA and RNA were detected by in situ hybridization (ISH) (RNA/DNAscope) and IHC was used to detect cellular markers (CD4, PD-1, FoxP3, and CTLA-4) by incorporating the tyramide system amplification (TSA) system. We evaluated latently infected cell lines, a primary cell model of HIV latency and excisional lymph node (LN) biopsies collected from people living with HIV (PLWH) on and off ART. We clearly detected infected cells that coexpressed HIV RNA and DNA (active replication) and DNA only (latently infected cells) in combination with IHC markers in the in vitro infection model as well as LN tissue from PLWH both on and off ART. Combining ISH targeting HIV RNA and DNA with IHC provides a platform to detect and quantify HIV persistence within cells identified by multiple markers in tissue samples from PLWH on ART or to study HIV latency.

BRAF Signaling Inhibition in Glioblastoma: Which Clinical Perspectives?

IDH-wild type (wt) glioblastoma (GB) accounts for approximately 90% of all GB and has a poor outcome. Surgery and adjuvant therapy with temozolomide and radiotherapy is the main therapeutic approach. Unfortunately, after relapse and progression, which occurs in most cases, there are very limited therapeutic options available. BRAF which plays a role in the oncogenesis of several malignant tumors, is also involved in a small proportion of IDH-wt GB. Previous successes with anti-B-Raf targeted therapy in tumors with V600E BRAF mutation like melanoma, combined with the poor prognosis and paucity of therapeutic options for GB patients is leading to a growing interest in the potential efficacy of this approach. This review is thus focused on dissecting the state of the art and future perspectives on BRAF pathway inhibition in IDH-wt GB. Overall, clinical efficacy is mostly described within case reports and umbrella trials, with promising but still insufficient results to draw more definitive conclusions. Further studies are needed to better define the molecular and phenotypic features that predict for a favorable response to treatment. In addition, limitations of B-Raf-inhibitors, in monotherapy or in combination with other therapeutic partners, to penetrate the blood-brain barrier and the development of acquired resistance mechanisms responsible for tumor progression need to be addressed.

Bilobed intramedullary and extramedullary bronchogenic cyst of the conus medullaris: illustrative case

BACKGROUND

Spinal bronchogenic cysts are rare nonneoplastic congenital variants of neurenteric cysts. The natural history and surgical management of these lesions are poorly understood.

OBSERVATIONS

A 25-year-old male presented with progressive back pain and bilateral lower limb sciatica of 6 months’ duration. He had undergone subtotal resection of an intramedullary bronchogenic conus medullaris cyst 5 years prior. Magnetic resonance imaging revealed a recurrent bilobed intramedullary and extramedullary conus medullaris cystic lesion. The authors resected the lesion via a posterior approach with the aid of intraoperative neuromonitoring. Gross total resection was precluded by the tightly adherent nature of the cyst and the fact that stimulation of a residual intramedullary portion of the lesion evoked external anal sphincter responses.

LESSONS

This is the first reported case of a bilobed intramedullary and extramedullary bronchogenic cyst of the conus medullaris. This unique case lends insight into the poorly defined embryogenesis of bronchogenic cysts by favoring the split notochord syndrome theory rather than the ectopic ectoderm proposal. The importance of neuromonitoring when resecting these tightly adherent lesions is demonstrated. Finally, although the secretory nature of these lesions portends a tendency for cyst reaccumulation, it is imperative to recognize that this is usually a slow process.

SP142 PD-L1 Scoring Shows High Interobserver and Intraobserver Agreement in Triple-negative Breast Carcinoma But Overall Low Percentage Agreement With Other PD-L1 Clones SP263 and 22C3

SP142 programmed cell death ligand 1 (PD-L1) status predicts response to atezolizumab in triple-negative breast carcinoma (TNBC). Prevalence of VENTANA PD-L1 (SP142) Assay positivity, concordance with the VENTANA PD-L1 (SP263) Assay and Dako PD-L1 IHC 22C3 pharmDx assay, and association with clinicopathologic features were assessed in 447 TNBCs. SP142 PD-L1 intraobserver and interobserver agreement was investigated in a subset of 60 TNBCs, with scores enriched around the 1% cutoff. The effect of a 1-hour training video on pretraining and posttraining scores was ascertained. At a 1% cutoff, 34.2% of tumors were SP142 PD-L1 positive. SP142 PD-L1 positivity was significantly associated with tumor-infiltrating lymphocytes (P <0.01), and node negativity (P=0.02), but not with tumor grade (P=0.35), tumor size (P=0.58), or BRCA mutation (P=0.53). Overall percentage agreement (OPA) for intraobserver and interobserver agreement was 95.0% and 93.7%, respectively, among 5 pathologists trained in TNBC SP142 PD-L1 scoring. In 5 TNBC SP142 PD-L1-naive pathologists, significantly higher OPA to the reference score was achieved after video training (posttraining OPA 85.7%, pretraining OPA 81.5%, P<0.05). PD-L1 status at a 1% cutoff was assessed by SP142 and SP263 in 420 cases, and by SP142 and 22C3 in 423 cases, with OPA of 88.1% and 85.8%, respectively. The VENTANA PD-L1 (SP142) Assay is reproducible for classifying TNBC PD-L1 status by trained observers; however, it is not analytically equivalent to the VENTANA PD-L1 (SP263) Assay and Dako PD-L1 IHC 22C3 pharmDx assay.

Solitary subependymal giant cell astrocytoma: Case report and review of the literature

Tuberous sclerosis complex (TSC) is a multisystem autosomal dominant hamartoma syndrome caused by mutations in TSC1 or TSC2 genes, leading to upregulation of cell growth signalling pathways. Subependymal giant cell astrocytomas (SEGAs) are seen almost exclusively in TSC patients. We report a 'solitary SEGA' in an adult patient, with confirmed deletion of the entire TSC2 gene on tumour tissue DNA, in the absence of detectable constitutional mutation or clinical manifestations of TSC. These rare cases may be secondary to somatic mosaicism and provide an opportunity to explore the genetic basis of the syndrome and its related tumours.

The Genomic Landscape of Sporadic Prolactinomas

Somatic GNAS and USP8 mutations have been implicated in sporadic somatotrophinomas and corticotrophinomas, respectively. However, no genes are known to be recurrently mutated in sporadic prolactinomas. The prevalence of copy number variants (CNV), which is emerging as a mechanism of tumorigenesis in sporadic pituitary adenomas in general, is also unclear in prolactinomas. To characterize the genetic events underpinning sporadic prolactinomas, we performed whole exome sequencing of paired tumor and germline DNA from 12 prolactinoma patients. We observed recurrent large-scale CNV, most commonly in the form of copy number gains. We also identified sequence variants of interest in 15 genes. This included the DRD2, PRL, TMEM67, and MLH3 genes with plausible links to prolactinoma formation. Of the 15 genes of interest, CNV was seen at the gene locus in the corresponding tumor in 10 cases, and pituitary expression of eight genes was in the top 10% of tissues. However, none of our shortlisted somatic variants appeared to be classical driver mutations as no variant was found in more than one tumor. Future directions of research include mechanistic studies to investigate how CNV may contribute to prolactinoma formation, larger studies of relevant prolactinoma subsets according to clinical characteristics, and additional genetic investigations for aberrations not captured by whole exome sequencing.

The Golgi Associated Calcium Pumps in Human Breast Cancer

The Golgi apparatus, located within the cell, is an intracellular calcium store. Golgi calcium is implicated in roles including post-translational modification, cell signalling and cellular proliferation. In breast cancer, there is evidence of aberrations in Golgi-dependent processes, some of which are linked to calcium regulated enzymes and Golgi structure. Previous studies show that Golgi-associated calcium pumps sequester calcium into the Golgi apparatus via an active transport mechanism requiring ATP. We investigated Golgi-associated calcium pumps in the context of breast cancer. Analysis of clinical breast sample and breast cancer cell line microarray databases indicates that different breast cancer subtypes may be characterized by alterations in Golgi calcium signalling. To explore this further, we assessed calcium transporter transcription in a bank of breast cancer-derived cell lines and non-malignant-derived breast cell lines using real time RT-PCR. The consequences of silencing Golgi calcium transporter expression were assessed using Dharmacon Smartpool On Target Plus siRNA. Inhibition (greater than 90%) was confirmed with real time RT-PCR 24, 72, 96 and 120 hours post transfection (P &lt; 0.05). Effects of inhibition on calcium signalling, proliferation and induction and sensitization of breast cancer cells to endoplasmic reticulum stress via tunicamycin (0.1, 1, 10 µg/mL) was assessed. Endoplasmic reticulum stress was confirmed by measuring the induction of GRP94 mRNA expression. Effects on calcium signalling were characterized using a fluorescence imaging plate reader (FLIPR; Molecular DevicesTM) and a fluorescence calcium indicator. The nature of calcium responses to endoplasmic reticulum calcium mobilizing agents was assessed, agents included a sarcoplasmic-endoplasmic Ca2+-ATPase inhibitor, a purinergic agonist (ATP, 100 µM) and a protease activated receptor modulator. Collectively our results imply that some breast cancers are associated with a remodelling of Golgi calcium transport with functional consequences on calcium signalling in breast cancer cells. Modulators of Golgi calcium content in breast cancer may represent a novel therapeutic approach for some breast breast cancer subtypes.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1129.

Stereochemistry of the major rat liver microsomal metabolites of the carcinogen 7-methylbenz[c]acridine

The major metabolites of the carcinogen 7-methylbenz[c]acridine (7MBAC), trans-5,6-dihydro-5,6-dihydroxy-7-methylbenz[c]acridine (7MBAC-5,6-DHD), and trans-8,9-dihydro-8,9-dihydroxy-7-methylbenz[c]acridine (7MBAC-8,9-DHD) were characterized as their enantiomers after separation of their bis-(+)-(1R,2S,4S)-endo-1,4,5,6,7,7-hexachlorobicyclo[2.2.1]hept-5 -ene-2-carboxylic acid [(+)-HCA] esters and hydrolysis. The synthetic precursor, trans-3,4-dihydroxy-7-methyl-1,2,3,4-tetrahydrobenz[c]acridine (7MBAC-3,4-THD), was similarly separated into enantiomers, and the dihydrodiol trans-3(S),4(S)-dihydro-3,4-dihydroxy-7-methylbenz[c]acridine (7MBAC-3,4-DHD) was prepared from 7MBAC-3(S),4(S)-THD. Absolute configurations were assigned by the chiral exciton coupling of the bis-p-(dimethylamino)benzoate of 7MBAC-3(R),4(R)-THD, and by the semiempirical methods based on the biaryl chromophores of the enantiomers of 7MBAC-5,6-DHD and of the methanolysis products of the 5,6-oxide of 7MBAC which were resolved as their (+)-HCA esters. X-ray crystallography was used for 7MBAC-8(S),9(S)-DHD bis-(+)-HCA ester, and assignments were correlated with chiral exciton coupling of the bis-4-(dimethylamino)cinnamates of 7MBAC-5(R),6(R)-DHD and 7MBAC-8(S),9(S)-DHD. The stereochemical compositions of four metabolites (three dihydrodiols and 7MBAC-5,6-oxide) formed in incubations with rat liver microsomes from control and induced liver were determined by normal-phase separations of bis-(+)-HCA esters, and by chiral stationary-phase separation of the 5,6-oxide methanolysis products. The 3(R),4(R)-enantiomer of 7MBAC-3,4-dihydrodiol predominated, 74-98% enantiomeric purity, and purity for the oxide varied from about 71% 5(R),6(S)-oxide for control microsomes to about 28% 5(R),6(S)-oxide for liver microsomes obtained from 3-methylcholanthrene-pretreated rats.

Photochemical studies on the anti-inflammatory drug diclofenac

Irradiation with UVA light of the anti-inflammatory drug diclofenac [2-(2,6-dichloroanilino)phenylacetic acid] in aqueous buffer or methanol solution leads to sequential loss of both chlorine substituents and ring closure to carbazole-1-acetic acid as the major product. Minor products result from substitution by the solvent. The photosensitizing properties of diclofenac and its major photoproduct were tested with singlet oxygen substrates and in the free radical polymerization of acrylamide. Although the major carbazole product is a weakly phototoxic agent, able to generate singlet oxygen more efficiently than diclofenac, the free radical photodechlorination process is postulated as the probable initiation step of in vivo photosensitivity responses.

Activation of the food-derived mutagen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine by rabbit and human liver microsomes and purified forms of cytochrome P-450

The specificity of rabbit cytochrome P-450 involved in the mutagenic activation of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was assessed using control and induced rabbit liver and lung microsomes, and six purified forms of cytochrome P-450. The number of revertants produced/2.5 micrograms PhIP by control rabbit liver was 260 +/- 196/10 micrograms of microsomal protein (mean +/- SD; n = 3), and this increased to 1265 +/- 248 when 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced liver microsomes were used as the activation source in the Ames test. Microsomes form phenobarbital-, rifampicin- and acetone-pretreated rabbits showed no increase in activity over controls. Control lung microsomes did not activate PhIP to a mutagen, whereas TCDD-induced lung microsomes produced 1443 +/- 136 (mean +/- SD; n = 4) Ames/Salmonella revertants/100 micrograms protein. In reconstitution experiments cytochrome P450 forms 4 and 6 were found to be efficient activators of PhIP to a mutagen Form 6 was 3.1-fold more active than form 4 and produced 4577 revertants/10 pmol with a 20-min preincubation step in the Ames test. Cytochrome form 5 produced 17 revertants/10 pmol and forms 2, 3b and 3c were not active in metabolizing PhIP to a mutagen. A highly significant statistical correlation existed between the capacity of control and induced liver microsomes to activate PhIP to a mutagen and their cytochrome P-450 form 4 (r = 0.97, r2 = 0.94) and form 6 (r = 0.95, r2 = 0.90) content. These data strongly support the involvement of polycyclic hydrocarbon-inducible forms of cytochrome P450 in the activation of PhIP in the rabbit. Anti-rabbit forms 4 and 6 IgGs recognized proteins in seven human liver microsomes of comparable mol. wt to rabbit cytochrome P-450 forms 4 and 6. However, no correlation existed between the content of these proteins and the capacity of human liver microsomes to activate PhIP.