Development of a high dimensional imaging mass cytometry panel to investigate spatial organization of tissue microenvironment in formalin-fixed archival clinical tissues.

To decipher the interactions between various components of the tumor microenvironment (TME) and tumor cells in a preserved spatial context, a multiparametric approach is essential. In this pursuit, imaging mass cytometry (IMC) emerges as a valuable tool, capable of concurrently analyzing up to 40 parameters at subcellular resolution. In this study, a set of antibodies was selected to spatially resolve multiple cell types and TME elements, including a comprehensive panel targeted at dissecting the heterogeneity of cancer-associated fibroblasts (CAF), a pivotal TME component. This antibody panel was standardized and optimized using formalin-fixed paraffin-embedded tissue (FFPE) samples from different organs/lesions known to express the markers of interest. The final composition of the antibody panel was determined based on the performance of conjugated antibodies in both immunohistochemistry (IHC) and IMC. Tissue images were segmented employing the Steinbock framework. Unsupervised clustering of single-cell data was carried out using a bioinformatics pipeline developed in R program. This paper provides a detailed description of the staining procedure and analysis workflow. Subsequently, the panel underwent validation on clinical FFPE samples from head and neck squamous cell carcinoma (HNSCC). The panel and bioinformatics pipeline established here proved to be robust in characterizing different TME components of HNSCC while maintaining a high degree of spatial detail. The platform we describe shows promise for understanding the clinical implications of TMA heterogeneity in large patient cohorts with FFPE tissues available in diagnostic biobanks worldwide.

TP53 mutation and human papilloma virus status as independent prognostic factors in a Norwegian cohort of vulva squamous cell carcinoma.

INTRODUCTION: Vulva squamous cell carcinoma (VSCC) develops through two separate molecular pathways-one involving high-risk human papilloma virus infection (HPV-associated), and the other without HPV infection (HPV-independent) often involving TP53 mutation. HPV-associated VSCC generally has a better progression-free survival than HPV-independent VSCC. The aim of this study was to determine TP53 mutation status using immunohistochemistry, compare different methods of HPV detection and correlate both with survival in a retrospective cohort of 123 patients with VSCC. MATERIAL AND METHODS: Immunohistochemistry for p53, Ki67 and p16INK4A (a surrogate marker for HPV infection) was performed on formalin-fixed paraffin-embedded tissues from a cohort of surgically treated VSCC patients to identify molecular subtypes of VSCC. Presence of HPV infection was detected by HPV DNA PCR and HPV mRNA in situ hybridization (ISH). The Pearson chi-square test and multivariable Cox regression model were used to investigate the association of different parameters with progression-free survival and disease-specific survival (DSS), and Kaplan-Meier curves were used to show the association of different parameters with survival. RESULTS: The results of p53 and p16INK4A immunohistochemistry confirmed three VSCC subtypes associated with different prognosis. The TP53 mutation status was identified as an independent prognostic factor of worse progression-free survival (p = 0.024) after adjustment for FIGO stage. p16INK4A immunohistochemistry, mRNA ISH, and DNA PCR had excellent concordance in terms of HPV detection. According to the multivariable Cox regression model, the presence of hrHPV mRNA correlated significantly with increased progression-free survival (p = 0.040) and DSS (p = 0.045), after adjustment for other confounders. CONCLUSIONS: p53 and p16INK4A immunohistochemistry stratify VSCC cohort into three subtypes with TP53mutated patients having the worst prognosis. The detection of hrHPV mRNA by ISH was an independent predictor of increased survival. Thus, the combined detection of p53 and HPV mRNA might improve risk stratification in VSCC.

Impact of KRAS and BRAF mutations on treatment efficacy and survival in high-grade gastroenteropancreatic neuroendocrine neoplasms.

High-grade gastroenteropancreatic neuroendocrine neoplasms (HG GEP-NEN) typically disseminate early. Treatment of metastatic disease has limited benefit and prognosis is generally discouraging. Data on the clinical impact of mutations in HG GEP-NEN are scarce. There is an unmet need for reliable biomarkers to predict treatment outcome and prognosis in metastatic HG GEP-NEN. Patients with metastatic HG GEP-NEN diagnosed at three centres were selected for KRAS-, BRAF mutation and microsatellite instability (MSI) analyses. Results were linked to treatment outcome and overall survival. After pathological re-evaluation, 83 patients met inclusion criteria: 77 (93%) GEP neuroendocrine carcinomas (NEC) and six (7%) GEP neuroendocrine tumours (NET) G3. NEC harboured higher frequency of mutations than NET G3. Colon NEC harboured a particular high frequency of BRAF mutations (63%). Immediate disease progression on first-line chemotherapy was significantly higher for NEC with BRAF mutation (73%) versus wild-type (27%) (p = .016) and for colonic primary (65%) versus other NEC (28%) (p = .011). Colon NEC had a significant shorter PFS compared to other primary sites, a finding independent of BRAF status. Immediate disease progression was particularly frequent for BRAF mutated colon NEC (OR 10.2, p = .007). Surprisingly, BRAF mutation did not influence overall survival. KRAS mutation was associated with inferior overall survival for the whole NEC population (HR 2.02, p = .015), but not for those given first-line chemotherapy. All long-term survivors (>24 m) were double wild-type. Three NEC cases (4.8%) were MSI. Colon NEC with BRAF mutation predicted immediate disease progression on first-line chemotherapy, but did not affect PFS or OS. Benefit of first-line platinum/etoposide treatment seems limited for colon NEC, especially for BRAF mutated cases. KRAS mutations did not influence treatment efficacy nor survival for patients receiving first-line chemotherapy. Both frequency and clinical impact of KRAS/BRAF mutations in digestive NEC differ from prior results on digestive adenocarcinoma.

Randomized Implementation of a Primary Human Papillomavirus Testing-based Cervical Cancer Screening Protocol for Women 34 to 69 Years in Norway.

BACKGROUND: Cervical cancer screening programs are facing a programmatic shift where screening protocol based on human papillomavirus testing (HPV-Screening protocol) is replacing the liquid-based cytology (LBC-Screening protocol). For safe technology transfer within the nationwide screening programme in Norway, HPV-Screening protocol was implemented randomized to compare the real-world effectiveness of HPV-Screening protocol and LBC-Screening protocol at the first screening round. METHODS: Among 302,295 women ages 34 to 69 years scheduled to attend screening from February 2015 to June 2017, 157,447 attended. A total of 77,207 were randomly allocated to the HPV-Screening protocol and 80,240 were allocated to the LBC-Screening protocol. All women were followed up for 18 months. RESULTS: The HPV-Screening protocol resulted in a relative increase of 60% in the detection of cervical intraepithelial neoplasia (CIN) grade 2 or worse [risk ratio (RR) = 1.6, 95% confidence interval (CI) = 1.5-1.7], 40% in CIN grade 3 or worse (RR = 1.4, 95% CI = 1.3-1.6), 40% in cancer (RR = 1.4, 95% CI = 1.0-2.1), and 60% in colposcopy referrals (RR = 1.6, 95% CI = 1.5-1.6) compared with LBC-Screening. The performance of both protocols was age dependent, being more effective in women ages under 50 years. CONCLUSIONS: The HPV-Screening protocol was well accepted by women in Norway and detected more CIN2, CIN3, and cancers compared with the LBC-Screening protocol. IMPACT: A randomized implementation of the HPV-Screening protocol with real-world assessment enabled a gradual, quality assured, and safe technology transition. HPV-based screening protocol may further be improved by using HPV genotyping and age-specific referral algorithms.

Tumor Infiltration Levels of CD3, Foxp3 (+) Lymphocytes and CD68 Macrophages at Diagnosis Predict 5-Year Disease-Specific Survival in Patients with Oropharynx Squamous Cell Carcinoma.

Head and neck cancer (HNC) is the sixth most common cancer worldwide. Oropharyngeal (OP) cancers are of special interest because of possible underlying HPV infection which is tied to prognosis. Influxes of inflammatory cells into tumors may vary with prognoses. We wanted to study whether the number of tumor-infiltrating lymphocytes (TIL) and tumor-associated macrophages (TAM) in tumors correlated to HPV status and predicted 5-year disease-specific survival (DSS). Formalin-fixed paraffin-embedded (FFPE) biopsies cut sections from 170 patients treated for OP cancer were stained by immunohistochemistry and evaluated for the number of CD68 (+) TAMs, CD3 (+), and Foxp3 (+) (T regulatory) TILs. From FFPE slides HPV by PCR and p16 by immunohistochemistry were established. From FFPE Hematoxylin-Eosin slides, levels of tumor nuclear polymorphism, tumor invasion, desmoplasia, and inflammation were determined as previously published. Levels of TIL CD3 (+) and TIL Foxp3 (+) were increased among the HPV (+) compared to the HPV (-) patients. High levels of TIL Foxp3 (+) and CD68 (+) macrophages predicted better 5-year DSS. TIL Foxp3 (+) levels predicted independent of age, gender, TNM stage, and HPV infection as well as level of stromal desmoplasia, tumor invasion, and nuclear polymorphism, but more pronounced among tumor HPV (+) than HPV (-) patients.

Profiling and Functional Analysis of microRNA Deregulation in Cancer-Associated Fibroblasts in Oral Squamous Cell Carcinoma Depicts an Anti-Invasive Role of microRNA-204 via Regulation of Their Motility.

Background: Knowledge on the role of miR changes in tumor stroma for cancer progression is limited. This study aimed to investigate the role of miR dysregulation in cancer-associated fibroblasts (CAFs) in oral squamous cell carcinoma (OSCC). Methodology: CAF and normal oral fibroblasts (NOFs) were isolated from biopsies of OSCC patients and healthy individuals after informed consent and grown in 3D collagen gels. Total RNA was extracted. Global miR expression was profiled using Illumina version 2 panels. The functional impact of altered miR-204 expression in fibroblasts on their phenotype and molecular profile was investigated using mimics and inhibitors of miR-204. Further, the impact of miR-204 expression in fibroblasts on invasion of adjacent OSCC cells was assessed in 3D-organotypic co-cultures. Results: Unsupervised hierarchical clustering for global miR expression resulted in separate clusters for CAF and NOF. SAM analysis identified differential expression of twelve miRs between CAF and NOF. Modulation of miR-204 expression did not affect fibroblast cell proliferation, but resulted in changes in the motility phenotype, expression of various motility-related molecules, and invasion of the adjacent OSCC cells. 3' UTR miR target reporter assay showed ITGA11 to be a direct target of miR-204. Conclusions: This study identifies differentially expressed miRs in stromal fibroblasts of OSCC lesions compared with normal oral mucosa and it reveals that one of the significantly downregulated miRs in CAF, miR-204, has a tumor-suppressive function through inhibition of fibroblast migration by modulating the expression of several different molecules in addition to directly targeting ITGA11.

Spontaneous Splenic Artery Rupture as the First Symptom of Systemic Amyloidosis.

Spontaneous splenic rupture is a life-threatening condition leading to a rapidly progressing hypovolemic shock due to intra-abdominal blood loss, with a mortality rate of about 10%. Spontaneous splenic rupture can be caused by widely different disorders including acute and chronic infections, neoplastic disorders, and inflammatory noninfectious disorders. In this case report, we present a 67-year-old male patient with hemorrhagic shock caused by an acute bleeding from the splenic artery. The patient was massively transfused with blood products and fluids and underwent laparotomy for hemostatic control and clinical stabilization. Multiorgan involvement by amyloid light-chain amyloidosis (AL-amyloidosis) caused by plasma cell dyscrasia, specifically with infiltration of the spleen artery, was found to be the underlying cause of his life-threatening bleeding. Based on this case, we discuss the features of serious spleen bleeding, massive transfusion therapy in the intensive care setting, and AL-amyloidosis pathophysiology and treatment.

Establishment of a novel cancer cell line derived from vulvar carcinoma associated with lichen sclerosus exhibiting a fibroblast-dependent tumorigenic potential.

Vulvar squamous cell carcinoma associated with lichen sclerosus (VLS-VSCC) are rare tumors but with higher recurrence and worse prognosis than other types of VSCC. Lack of experimental models has limited the search for better understanding of the biology and development of treatment modalities. In this study, we isolated and characterized primary cells from VSCC (n = 7) and normal vulvar tissue adjacent to tumor (n = 7). Detailed characterization of the novel spontaneously immortalized cell line, VCC1 revealed a characteristic epithelial morphology in vitro and a well-differentiated keratinizing SCC histology in vivo, closely resembling the tumor of origin. VCC1 expressed higher levels of epithelial-mesenchymal transition markers and higher clonogenic properties as compared to other established non VLS-VSCC cell lines. In vitro 3D organotypic assays and in vivo xenografts revealed a prominent role of cancer-associated fibroblasts in VCC1 invasion and tumor formation. In conclusion, VCC1 mirrored several major VLS-VSCC features and provided a robust experimental tool for further elucidation of VLS-related oncogenesis and drug testing.

Periodontal status at diagnosis predicts non-disease-specific survival in a geographically defined cohort of patients with oropharynx squamous cell carcinoma.

BACKGROUND: The aim of this study was to examine periodontal status with a time-efficient screening method from a cohort of newly diagnosed oropharynx squamous cell carcinoma (OPSCC) patients and to study to what extent dental disease level predicted survival. Aims/objective: Can measuring level of dental pathology based on a blind investigation of a routine orthopantogram (OPG) obtained during diagnostic workup reveal prognostic information? MATERIALS AND METHODS: We included 97 patients diagnosed between 2003 and 2010. Radiographic alveolar bone loss was measured. At least 4 mm bone loss from cement-enamel junction on at least two teeth was registered as periodontal pathology. The number of missing and filled teeth (MFT), residual roots and apical radiolucencies were noted. Clinical data were determined through hospital patient records. RESULTS: The horizontal bone loss discriminated between hr-HPV(+) versus hr-HPV(-) status, but secondary to age and smoking history at diagnosis. Vertical and horizontal bone loss predicted survival directly, and adjusted by gender, patient, smoking history, TN stage and hr-HPV tumor infection at diagnosis. CONCLUSIONS: Degree of periodontal OPG pathology at the time of OPSCC diagnosis to some extent predicted hr-HPV infection, but predicted non-disease-specific long-term survival. SIGNIFICANCE: Degree of periodontal OPG pathology at diagnosis predicts prognosis.

Human papillomavirus type specific risk of progression and remission during long-term follow-up of equivocal and low-grade HPV-positive cervical smears.

The prevalence of clinically relevant HPV types and their specific risk for progression and regression in women with atypical squamous cells of uncertain significance (ASCUS) and low-grade squamous intraepithelial lesions (LSIL) were studied in a routine screening population. A 4-year cohort of women (n = 820) with ASCUS/LSIL and a positive HPV test in triage were followed for 6-9 years. The progression risks for CIN2+/CIN3+ were determined for single (71.2%) and multiple HPV infections (28.8%). The CIN2+ progression risk for all HPV 16, all HPV 35, single HPV 16 and single HPV 35 infections were 65.3% (95% CI: 59.6-71.0), 64.4% (95% CI: 50.4-78.4), 63.8% (95% CI: 56.2-71.4) and 73.7% (95% CI: 53.9-93.5), respectively. Based on CIN2+ progression risks four main groups were defined; the HPV 16 group, the HPV 31/33/35 group, the HPV 18/45/51/52 group and the HPV 39/56/58/59/66/68 group with progression risks of 65.3% (95% CI: 59.6-71.0), 62.1% (95% CI: 54.8-69.4), 52.6 (95% CI: 45.9-59.3) and 39.5 (95% CI: 33.0-46.0), respectively. In multivariate analyses, women in the age group 40-49 years had an increased risk of CIN2+ progression. As for CIN3+, HPV 16 had a higher progression risk than other HPV risk groups (p < 0.05). In multiple infections only HPV 16 had a significant additive CIN3+ progression risk (p < 0.05) as compared to other HPV risk groups. In summary, HPV types 16 and 35, including the HPV risk group 31/33/35, had a similar CIN2+ progression risk, but only HPV 16 had a higher risk for CIN3+ progression.

In Vitro-Stimulated IL-6 Monocyte Secretion and In Vivo Peripheral Blood T Lymphocyte Activation Uniquely Predicted 15-Year Survival in Patients with Head and Neck Squamous Cell Carcinoma.

The study was performed in order to determine whether peripheral blood monocyte in vitro function, and lymphocyte in vivo activation at diagnosis, was associated with HPV tumor infection status and 15-year survival in head and neck squamous cell carcinoma (HNSCC) patients. Sixty-five patients from a consecutive cohort of newly diagnosed HNSCCs, together with 18 control patients, were included in the study. Monocyte responsiveness was assessed by measuring monocyte in vitro interleukin (IL)-6 secretions after 24 hours of LPS stimulation in cultures with a serum-free medium. T lymphocyte activation was determined as the fraction of CD71-positive cells on CD3-positive cells by flow cytometry, whereas HPV infection was determined by PCR on formalin-fixed paraffin-embedded (FFPE) tumor tissue. Disease-specific survivals and overall survivals were determined 15 years following inclusion. HPV-positive HNSCC patients had a lower monocyte LPS-stimulated IL-6 response. A high LPS-stimulated monocyte IL-6 response predicted a decreased survival rate (P=0.019). A high percentage of CD71-positive T lymphocytes also predicted an impaired prognosis (P=0.021). The predictive power of IL-6 monocyte LPS-stimulated responses was retained when adjusted for age, gender and TNM stage of the patients. The monocyte and T lymphocyte survival predictions were independent of each other. The survival was particularly low with a combined high activated monocyte and T lymphocyte status. In a multivariate analysis, IL-6 secretion and the percentage of CD71-positive T lymphocytes both uniquely predicted survival independent of HPV infection status. It is postulated that the natural and adaptive immune systems are separately and additionally linked to the clinical aggressiveness of HNSCCs.

Excellent response of intramedullary Erdheim-Chester disease to vemurafenib: a case report.

BACKGROUND: Erdheim-Chester disease is a rare histiocytosis characterized by multi-systemic organ involvement. Immune-modulating agents such as interferon-alpha have limited success and the disorder is progressive and causes high morbidity and mortality. Treatment with the BRAF-inhibitor vemurafenib has recently produced substantial improvement in three patients with Erdheim-Chester disease expressing the p. V600E BRAF mutation. The disorder commonly affects the central nervous system and it is not yet known whether vemurafenib can reverse intra-axial infiltration and the resulting neurological impairment. CASE PRESENTATION: In this work, we report for the first time an excellent clinical response to vemurafenib in a Norwegian patient with debilitating progressive spastic paraparesis due to intra-axial infiltration of the thoracic spinal cord. The patient had been unresponsive to interferon-alpha. Low dose vemurafenib (720 mg daily) for a period of three months resulted in significant tumor shrinkage by >60% and regression of contrast enhancement and fluorodeoxyglucose uptake on positron-emission tomography. The patient's spastic paraparesis and gait function improved dramatically. She currently walks unaided and reports a substantially improved quality of life. CONCLUSION: Our findings show that vemurafenib therapy, even at low doses, can be effective for the treatment of intra-axial central nervous system involvement in BRAF-positive Erdheim-Chester disease.

IGHV gene usage and mutational status in follicular lymphoma: Correlations with prognosis and patient age.

Follicular lymphoma (FL) is a heterogeneous disease with some patients developing progressively or transformed disease early, whereas others follow an indolent clinical course. We evaluated the prognostic value of immunoglobulin heavy chain variable (IGHV) gene usage and mutational status in FL patients. One hundred and four IGH sequences were obtained in tumour samples from 99 patients. The IGHV3 subgroup had the highest usage frequency (57.7%) with IGHV3-23 being the most common sequence. Patients with the IGHV5 subgroup or IGHV sequences from more than one subgroup had significantly less favourable prognosis with an estimated 5-year survival of 62.5 and 50.0%, respectively, as compared with a 5-year survival of 95.1% for patients with other IGHV subgroups (P=0.013 and P<0.001, log-rank). The poor survival associated with IGHV5 or >1 IGHV subgroup usage was an independent prognostic factor in Cox multivariate analysis (P=0.005). IGHV genes were unmutated showing >98% homology in 15.2% of cases. Contrasting the situation in chronic lymphocytic leukaemia (CLL), the presence of unmutated sequences did not yield prognostic information, although unmutated sequences were associated with age at diagnosis >60 years (P=0.022, Fisher's exact). In conclusion, our results indicate that analysis of IGHV gene usage might aid in predicting prognosis for FL patients.

Prognostic value of bone marrow involvement by clonal immunoglobulin gene rearrangements in follicular lymphoma.

AIMS: We aimed to evaluate the prognostic value of routine use of PCR amplification of immunoglobulin gene rearrangements in bone marrow (BM) staging in patients with follicular lymphoma (FL). METHODS: Clonal rearrangements were assessed by immunoglobulin heavy and light-chain gene rearrangement analysis in BM aspirates from 96 patients diagnosed with FL and related to morphological detection of BM involvement in biopsies. In 71 patients, results were also compared with concurrent flow cytometry analysis. RESULTS: BM involvement was detected by PCR in 34.4% (33/96) of patients. The presence of clonal rearrangements by PCR was associated with advanced clinical stage (I-III vs IV; p<0.001), high FL International Prognostic Index (FLIPI) score (0-1, 2 vs ≥3; p=0.003), and detection of BM involvement by morphology and flow cytometry analysis (p<0.001 for both). PCR-positive patients had a significantly poorer survival than PCR-negative patients (p=0.001, log-rank test). Thirteen patients positive by PCR but without morphologically detectable BM involvement, had significantly poorer survival than patients with negative morphology and negative PCR result (p=0.002). The poor survival associated with BM involvement by PCR was independent of the FLIPI score (p=0.007, Cox regression). BM involvement by morphology or flow cytometry did not show a significant impact on survival. CONCLUSIONS: Our results showed that routine use of PCR-based clonality analysis significantly improved the prognostic impact of BM staging in patients with FL. BM involvement by PCR was also an independent adverse prognostic factor.

Distinct single cell signal transduction signatures in leukocyte subsets stimulated with khat extract, amphetamine-like cathinone, cathine or norephedrine.

BACKGROUND: Amphetamine and amphetamine derivatives are suggested to induce an immunosuppressive effect. However, knowledge of how amphetamines modulate intracellular signaling pathways in cells of the immune system is limited. We have studied phosphorylation of signal transduction proteins (Akt, CREB, ERK1/2, NF-κB, c-Cbl, STAT1/3/5/6) and stress sensors (p38 MAPK, p53) in human leukocyte subsets following in vitro treatment with the natural amphetamine cathinone, the cathinone derivatives cathine and norephedrine, in comparison with a defined extract of the psychostimulating herb khat (Catha edulis Forsk.). Intracellular protein modifications in single cells were studied using immunostaining and flow cytometry, cell viability was determined by Annexin V-FITC/Propidium Iodide staining, and T-lymphocyte proliferation was measured by (3)H-thymidine incorporation. RESULTS: Cathinone, cathine and norephedrine generally reduced post-translational modifications of intracellular signal transducers in T-lymphocytes, B-lymphocytes, natural killer cells and monocytes, most prominently affecting c-Cbl (pTyr700), ERK1/2 (p-Thr202/p-Tyr204), p38 MAPK (p-Thr180/p-Tyr182) and p53 (both total p53 protein and p-Ser15). In contrast, the botanical khat-extract induced protein phosphorylation of STAT1 (p-Tyr701), STAT6 (p-Tyr641), c-Cbl (pTyr700), ERK1/2 (p-Thr202/p-Tyr204), NF-κB (p-Ser529), Akt (p-Ser473), p38 MAPK (p-Thr180/p-Tyr182), p53 (Ser15) as well as total p53 protein. Cathinone, cathine and norephedrine resulted in unique signaling profiles, with B-lymphocytes and natural killer cells more responsive compared to T-lymphocytes and monocytes. Treatment with norephedrine resulted in significantly increased T-lymphocyte proliferation, whereas khat-extract reduced proliferation and induced cell death. CONCLUSIONS: Single-cell signal transduction analyses of leukocytes distinctively discriminated between stimulation with cathinone and the structurally similar derivatives cathine and norephedrine. Cathinone, cathine and norephedrine reduced phosphorylation of c-Cbl, ERK1/2, p38 MAPK and p53(Ser15), and norephedrine induced T-lymphocyte proliferation. Khat-extract induced protein phosphorylation of signal transducers, p38 MAPK and p53, followed by reduced cell proliferation and cell death. This study suggests that protein modification-specific single-cell analysis of immune cells could unravel pharmacologic effects of amphetamines and amphetamine-like agents, and further could represent a valuable tool in elucidation of mechanism(s) of action of complex botanical extracts.

Detection of clonality in follicular lymphoma using formalin-fixed, paraffin-embedded tissue samples and BIOMED-2 immunoglobulin primers.

AIMS: The BIOMED-2 multiplex PCR protocol is a commonly used procedure for assessing B cell clonality in lymphoma diagnostics. Follicular lymphoma poses a special challenge for PCR-based analyses because of high prevalence of somatic hypermutations in the rearranged immunoglobulin (IG) domains. This study aimed to evaluate the BIOMED-2 protocol performance in detection of B cell clonality in follicular lymphoma using formalin-fixed, paraffin-embedded (FFPE) tissue. METHODS: FFPE samples from 118 patients diagnosed with follicular lymphoma in the period 1998-2008 were used in the study. Clonality of IG heavy (IGH) and light chains (IGK, IGL) was assessed using a PCR procedure that was optimised for FFPE tissue. RESULTS: The highest clonal detection rates were 67.8% with the IGH Vн-FR2-Jн assay and 66.1% with the IGK Vκ-Jκ assay. Clonality was detected in 94.9% of all FFPE follicular lymphoma samples when all assays were combined. FFPE samples stored for 1-5 years did not perform significantly differently from those stored for 6-11 years. Interobserver agreement of clonality was tested for all analyses. The lowest score (Cohen's κ value = 0.56) was observed for the IGK Vκ-Jκ clonality assay. CONCLUSIONS: An improved PCR protocol for detection of clonality in FFPE samples using BIOMED-2 IG primers is presented. For best performance, a combination of IGH and IGK analyses is recommended.

Adverse effects of Sudanese toombak vs. Swedish snuff on human oral cells.

BACKGROUND: The high incidence of oral cancer in Sudan has been associated with the use of toombak, the local type of smokeless tobacco. However, its specific effects on human oral cells are not known. We aimed to investigate the effects of toombak on primary normal human oral keratinocytes, fibroblasts, and a dysplastic oral keratinocytic cell line, and to compare them with the effects induced by Swedish snuff. METHOD: Aqueous extracts were prepared from moist toombak and Swedish snuff and added in serial dilutions on in vitro monolayer cultured cells. Cell viability, morphology and growth, DNA double-strand breaks (gammaH2AX staining), expression of phosphatidylserine (Annexin V staining), and cell cycle were assessed after various exposure time periods. RESULTS: Significant decrease in cell number, occurrence of DNA double-strain breaks, morphological and biochemical signs of programmed cell death were detected in all oral cell types exposed to clinically relevant dilutions of toombak extract, although to a lesser extent in normal oral fibroblasts and dysplastic keratinocytes. G2/M-block was also detected in normal oral keratinocytes and fibroblasts exposed to clinically relevant dilutions of toombak extract. Swedish snuff extract had less adverse effects on oral cells, mainly at non-clinically relevant dilutions. CONCLUSION: This study indicates a potential for toombak, higher than for Swedish snuff, to damage human oral epithelium. Dysplastic oral keratinocytes were less sensitive than their normal counterparts, suggesting that they might have acquired a partially resistant phenotype to toombak-induced cytotoxic effects while still being prone to DNA damage that could lead to further malignant progression.