Tumor microenvironment of Burkitt lymphoma: different immune signatures with different clinical behavior.

Burkitt lymphoma (BL) is characterized by a tumor microenvironment (TME) in which macrophages represent the main component, determining a distinct histological appearance known as "starry sky" pattern. However, in some instances, BL may exhibit a granulomatous reaction that has been previously linked to favorable prognosis and spontaneous regression. The aim of our study was to deeply characterize the immune landscape of 7 cases of Epstein-Barr virus-positive (EBV+) BL with granulomatous reaction compared with 8 cases of EBV+ BL and 8 EBV-negative (EBV-) BL, both with typical starry sky pattern, by Gene expression profiling performed on the NanoString nCounter platform.

BRCA1 and BRCA2 mutations and their clinical relevance in selected women diagnosed with triple-negative breast cancer in Kenya: a descriptive cross-sectional study.

Introduction: triple-negative breast cancer (TNBC) is a heterogeneous breast cancer type with a poor prognosis. About 25% of TNBC patients carry breast cancer susceptibility genes 1 and 2 (BRCA1 and BRCA2) mutations. Screening for BRCA mutations would facilitate early detection and initiation of personalized therapy, thus improving prognosis.

Correction: Frequent traces of EBV infection in Hodgkin and non-Hodgkin lymphomas classified as EBV-negative by routine methods: expanding the landscape of EBV-related lymphomas.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Correction to: Immune landscape in Burkitt lymphoma reveals M2-macrophage polarization and correlation between PD-L1 expression and non-canonical EBV latency program.

[This corrects the article DOI: 10.1186/s13027-020-00292-w.].

Frequent traces of EBV infection in Hodgkin and non-Hodgkin lymphomas classified as EBV-negative by routine methods: expanding the landscape of EBV-related lymphomas.

The Epstein-Barr virus (EBV) is linked to various B-cell lymphomas, including Burkitt lymphoma (BL), classical Hodgkin lymphoma (cHL) and diffuse large B-cell lymphoma (DLBCL) at frequencies ranging, by routine techniques, from 5 to 10% of cases in DLBCL to >95% in endemic BL. Using higher-sensitivity methods, we recently detected EBV traces in a few EBV-negative BL cases, possibly suggesting a "hit-and-run" mechanism. Here, we used routine and higher-sensitivity methods (qPCR and ddPCR for conserved EBV genomic regions and miRNAs on microdissected tumor cells; EBNA1 mRNA In situ detection by RNAscope) to assess EBV infection in a larger lymphoma cohort [19 BL, 34 DLBCL, 44 cHL, 50 follicular lymphomas (FL), 10 T-lymphoblastic lymphomas (T-LL), 20 hairy cell leukemias (HCL), 10 mantle cell lymphomas (MCL)], as well as in several lymphoma cell lines (9 cHL and 6 BL).

Immune landscape in Burkitt lymphoma reveals M2-macrophage polarization and correlation between PD-L1 expression and non-canonical EBV latency program.

Background: The Tumor Microenviroment (TME) is a complex milieu that is increasingly recognized as a key factor in multiple stages of disease progression and responses to therapy as well as escape from immune surveillance. However, the precise contribution of specific immune effector and immune suppressor components of the TME in Burkitt lymphoma (BL) remains poorly understood.

Methods: In this paper, we applied the computational algorithm CIBERSORT to Gene Expression Profiling (GEP) datasets of 40 BL samples to draw a map of immune and stromal components of TME.

Molecular switch from MYC to MYCN expression in MYC protein negative Burkitt lymphoma cases.

MYC is the most altered oncogene in human cancer, and belongs to a large family of genes, including MYCN and MYCL. Recently, while assessing the degree of correlation between MYC gene rearrangement and MYC protein expression in aggressive B-cell lymphomas, we observed few Burkitt lymphoma (BL) cases lacking MYC protein expression despite the translocation involving the MYC gene. Therefore, in the present study we aimed to better characterize such cases.

Kaposi Sarcoma-Associated Herpesvirus Glycoprotein H Is Indispensable for Infection of Epithelial, Endothelial, and Fibroblast Cell Types.

Kaposi sarcoma-associated herpesvirus (KSHV) is an emerging pathogen and is the causative infectious agent of Kaposi sarcoma and two malignancies of B cell origin. To date, there is no licensed KSHV vaccine. Development of an effective vaccine against KSHV continues to be limited by a poor understanding of how the virus initiates acute primary infection in diverse human cell types.

Risk indicators and effects of hypertension on HIV/AIDS disease progression among patients seen at Kenyatta hospital HIV care center.

There is paucity of data on prevalence of hypertension and its effects on HIV/AIDS progression among patients at Kenyatta National Hospital (KNH), Kenya. This was a cross sectional study conducted between January and May 2015 at the KNH HIV Care Centre. Ethical approval was obtained from institutional ethics review board.

Prevalence of Drug Resistance Mycobacterium Tuberculosis among Patients Seen in Coast Provincial General Hospital, Mombasa, Kenya.

Background: Although prevention and control of spread of multi-drug resistant tuberculosis strains is a global challenge, there is paucity of data on the prevalence of DR-TB in patients diagnosed with TB in referral hospitals in Kenya. The present study assessed patients' characteristics and prevalence of drug resistant TB in sputa smear positive TB patients presenting to Coast Provincial General Hospital (CPGH) in Mombasa, Kenya.

Methods: Drug resistance was evaluated in 258 randomly selected sputa smear TB positive cases between the periods of November 2011 to February 2012 at the CPGH-Mombasa.

Effects of HIV-1 infection on malaria parasitemia in milo sub-location, western Kenya.

Background: Malaria and HIV infections are both highly prevalent in sub-Saharan Africa, with HIV-infected patients being at higher risk of acquiring malaria. HIV-1 infection is known to impair the immune response and may increase the incidence of clinical malaria. However, a positive association between HIV-1 and malaria parasitaemia is still evolving.

Correlation of EGFR, pEGFR and p16INK4 expressions and high risk HPV infection in HIV/AIDS-related squamous cell carcinoma of conjunctiva.

Background: Squamous cell carcinoma of conjunctiva has increased tenfold in the era of HIV/AIDS. The disease pattern has also changed in Africa, affecting young persons, with peak age-specific incidence of 30-39 years, similar to that of Kaposi sarcoma, a well known HIV/AIDS defining neoplasm. In addition, the disease has assumed more aggressive clinical course.

B-cell differentiation in EBV-positive Burkitt lymphoma is impaired at posttranscriptional level by miRNA-altered expression.

Endemic, sporadic and HIV-associated Burkitt lymphoma (BL) all have a B-cell phenotype and a MYC translocation, but a variable association with the Epstein-Barr virus (EBV). However, there is still no satisfactory explanation of how EBV participates in the pathogenesis of BL. A recent investigation suggested that EBV-positive and EBV-negative BL have different cells of origin.

Gene-expression analysis identifies novel RBL2/p130 target genes in endemic Burkitt lymphoma cell lines and primary tumors.

Burkitt lymphoma (BL) is a B-cell tumor whose characteristic gene aberration is the translocation t(8;14), which determines c-myc overexpression. Several genetic and epigenetic alterations other than c-myc overexpression have also been described in BL. It has been demonstrated that the RBL2/p130 gene, a member of the retinoblastoma family (pRbs), is mutated in BL cell lines and primary tumors.

Routine assessment of hormonal receptor and her-2/neu status underscores the need for more therapeutic targets in Kenyan women with breast cancer.

Objective: To report the expression of estrogen receptors, progesterone receptors and human epidermal growth factor receptor (Her-2/neu) in 158 Kenyan women with breast cancer and correlation with other prognostic indicators in this high-risk group. This study stressed the importance of routine assessment of the steroid receptors and Her-2/neu as a mode of therapeutic selection of patients for antihormonal or targeting monoclonal antibody (Herceptin) therapy, directed at the juxtamembrane domain of Her-2/neu protein in the developing countries such as Kenya.

Study Design: The study population consisted of 158 female patients with histologically confirmed breast carcinoma seen at the pathology department of The Nairobi Hospital.

Immunoglobulin gene analysis reveals 2 distinct cells of origin for EBV-positive and EBV-negative Burkitt lymphomas.

The normal counterpart of the neoplastic B cells in Burkitt lymphoma (BL) is still unclear. Based on immunoglobulin gene rearrangement studies, some authors suggest an origin from germinal center cells and others from memory B cells. However, most of these studies rely on cell lines or on a small series of cases.