The miRNA content of circulating exosomes in DLBCL patients and in vitro influence of DLBCL-derived exosomes on miRNA expression of healthy B cells from peripheral blood

BACKGROUND

Due to the heterogeneous nature of Diffuse Large B-cell Lymphoma (DLBCL), the mechanisms underlying tumor development and progression have not yet been fully elucidated.

OBJECTIVE

This study aimed to compare the characteristics of plasma exosomes of DLBCL patients and healthy individuals and to evaluate the exosomal interactions between DLBCL cell lines and normal B-cells.

METHODS

Exosome isolation was performed using an ultracentrifugation-based protocol from plasma of 20 patients with DLBCL and 20 controls. The expression of miRNAs from exosome samples was analyzed using a miRNA expression microarray. The presence of exosome-mediated communication between the lymphoma cells and normal B-cells was determined by the co-culture model.

RESULTS

A significant increase in plasma exosome concentrations of DLBCL patients was observed. There was also a significant decrease in the expression of 33 miRNAs in plasma exosomes of DLBCL patients. It was determined that normal B-cells internalize DLBCL-derived exosomes and then miRNA expression differences observed in normal B-cells are specific to lymphoma-subtypes.

CONCLUSIONS

MiR-3960, miR-6089 and miR-939-5p can be used as the miRNA signature in DLBCL diagnosis. We suppose that the exosomes changed the molecular signature of the target cells depending on the genomic characterization of the lymphoma cells they have originated.

Mutational status of EZH2 and CD79B hot spots in mature B-cell non-Hodgkin's lymphomas: novel CD79B variations have been revealed

OBJECTIVE

We aimed to determine the hot spot mutational frequencies of Enhancer of Zeste homolog 2 (EZH2) and cluster of differentiation 79B (CD79B) genes in a cohort of mature B-cell non-Hodgkin's lymphomas.

PATIENTS AND METHODS

DNA samples from formalin-fixed and paraffin embedded (FFPE) tissues from a total of 37 patients with mature B-cell non-Hodgkin lymphomas were included in the study. Molecular genetic analysis was performed by direct sequencing of the DNA samples.

RESULTS

We analyzed formaldehyde fixed-paraffin embedded (FFPE) tumor tissue samples from 17 female and 20 male patients with a median age of 63.7 years at the time of diagnosis. None of the patients had previously reported hot spot mutations in EZH2 and CD79B, but previously unreported single nucleotide variations of CD79B were present in nine patients. rs779833118 was the most frequent variation (7/37 patients, 18.9%). A non-synonymous variation rs757407417, which could have a potentially damaging outcome, was detected in two patients.

CONCLUSIONS

None of the patients had well-known hot spot mutations in EZH2 and CD79B. However, we detected novel CD79B variations in mature B-cell non-Hodgkin's lymphoma patients.

MYD88 expression and L265P mutation in mature B-cell non-Hodgkin lymphomas

BACKGROUND

Myeloid differentiation primary response 88 (MYD88) is a common adaptor protein that is responsible for signaling from several receptors; mutations in this gene may play a role in the pathogenesis of lymphoma.

AIM

We aimed to determine the MYD88 L265P mutation frequency, the level of MYD88 expression, and their associations with clinicopathological parameters in mature B-cell non-Hodgkin lymphomas (NHLs).

METHODS

A total of 68 patients were included in the study. The presence of the MYD88 L265P mutation was analyzed by real-time polymerase chain reaction and direct sequencing. MYD88 protein expression was evaluated by immunohistochemistry (IHC) using two different scoring systems.

RESULTS

MYD88 L265P mutation was present in eight (18.6%) diffuse large B-cell lymphoma (DLBCL) patients. We also observed a significant association between the loss of MYD88 expression and advanced stage in both mature B-cell NHL and DLBCL according to the first IHC scoring systems (p=0.015 and p=0.024, respectively). An association was also seen between MYD88 overexpression and low clinical risk in both mature B-cell NHL and DLBCL according to the second IHC scoring system (p=0.027 and p=0.024, respectively).

CONCLUSIONS

The L265P mutation may be helpful for understanding the pathogenesis of immune-privileged site-associated DLBCLs. The presence of the mutation, together with its protein overexpression, could also be used as a prognostic marker in advanced stage DLBCLs.

Utility of serum DNA and pyrosequencing for the detection of EGFR mutations in non-small cell lung cancer

Mutations in the EGFR gene are critical determinants of treatment with EGFR tyrosine kinase inhibitors (TKIs) for non-small cell lung cancer (NSCLC) patients. DNA isolation from tumor samples usually requires surgery; therefore, we wanted to isolate DNA from circulating tumor cells by using the serum of NSCLC patients. This protocol was recently published. DNA was isolated from the serum of 52 Turkish NSCLC patients and their EGFR mutation status was examined by pyrosequencing. EGFR mutations were detected in 25 of the 52 patients (48.1%): 17 patients with delE746-A750, 2 with delE747-A750insP, and 6 with L858R. All mutations detected by pyrosequencing were confirmed by dideoxy sequencing, and the presence of the same mutations in the tumors was verified by using paraffin embedded tissues of all the patients. Mutations were detected more frequently in adenocarcinomas (24 of 36, 66.7%) than in squamous cell carcinomas (1 of 16, 6.3%) (P<0.001). These results confirm the utility of serum DNA and pyrosequencing for the detection of EGFR mutations in patients with advanced NSCLC.

Prenatal diagnosis of β-thalassemia and other hemoglobinopathies in southwestern Turkey

Our aim was to evaluate the prenatal diagnosis of β-thalassemia (β-thal) and other hemoglobinopathies in a region with high frequency. After detection by premarital or antenatal screening, 312 patients underwent 420 prenatal diagnostic procedures for 407 fetuses in a 10-year period. Fetal samples were collected by chorionic villi sampling (CVS) in the first trimester and amniocentesis and cordocentesis in the second trimester. Mutation analyses of β-globin and cytogenetic analyses were performed and the most common mutations detected were: IVS-I-110 (G>A), IVS-II-1 (G>A), IVS-I-6 (T>C) and IVS-II-745 (C>G). Hb S [β6(A3)Glu→Val, GAG>GTG)] was the most common hemoglobin (Hb) variant with a frequency of 6.3%. Among 407 fetuses, 105 (25.8%) were diagnosed as affected, while 201 (49.4%) were carriers and 101 (24.8%) were normal. Cytogenetic analyses revealed nine fetuses (2.3%) with numerical chromosomal abnormalities as regular or mosaicism. Prenatal diagnosis of common hemoglobinopathies is safe and effective. Performing cytogenetic analysis in excess fetal material is an acceptable option.

Complete gonadal dysgenesis 46,XY (Swyer syndrome) in two sisters and their mother's maternal aunt with a female phenotype

OBJECTIVE

To present a familial case of Swyer syndrome.

DESIGN

Case report.

SETTING

Academic medical center.

PATIENT(S)

Two sisters with a main complaint of primary amenorrhea and another case, their mother's maternal aunt with the same history of primary amenorrhea but married with no consanguinity and no children.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The patients were studied from clinical, endocrinologic, and genetic perspectives.

RESULT(S)

Chromosome analyses revealed a 46,XY male karyotype with no detectable mosaicism in both sisters and their mother's maternal aunt. Molecular studies of sex-determining region Y and molecular investigation undertaken for the two sisters revealed SRY negativity.

CONCLUSION(S)

Gonadal dysgenesis can also be inherited as an X-linked disorder, and evidence exists from familial studies of perhaps autosomal inheritance.

Triploidy in a Growth Discordant Twin Pregnancy after Intracytoplasmic Sperm Injection Treatment

OBJECTIVE

We report on a case of a triploidy in one fetus of a twin pregnancy who presented with the findings of growth discordance.

METHODS

Three weeks' difference between fetuses in ultrasonographic measurements in the first trimester was observed in a twin pregnancy following intracytoplasmic sperm injection (ICSI) treatment for male infertility. Hydrocephaly developed in the growth-discordant fetus subsequently. Amniocentesis for both fetuses and selective feticide for the abnormal one was performed at 19 weeks' gestation through a single insertion. Fetal karyotype of the abnormal one was 69,XXX and the healthy one was 46,XX.

CONCLUSION

Early developed growth discordance in a twin pregnancy may be a sign of chromosomal abnormality such as triploidy. Those cases should be karyotyped without delay to decrease preterm delivery risk of possible selective feticide.

The effect of cyclosporin A on cultured rabbit subconjunctival fibroblast proliferation

The aim of this study was to examine the possible effects of local application of a potent immunosuppressive drug, cyclosporin A (CsA), on fibroblast proliferation in vitro. Rabbit subconjunctival fibroblasts were cultured and incubated with varying doses of CsA (from 0.5 to 5%). Growth inhibition curves were obtained, and cell attachment and reversibility of drug-induced growth inhibition were studied. None of the doses stimulated fibroblast proliferation. CsA inhibited fibroblast proliferation depending on the dose and duration of application. Also, drug-induced growth inhibition decreased depending on dose and duration of application. While the dosage which led to 50% inhibition was found to be 7.2 mg/ml, 4% and higher doses had toxic effects.

Parental origin and mechanisms of formation of cytogenetically recognisable de novo direct and inverted duplications

Cytogenetic, FISH, and molecular results of 20 cases with de novo tandem duplications of 18 different autosomal chromosome segments are reported. There were 12 cases with direct duplications, three cases with inverted duplications, and five in whom determination of direction was not possible. In seven cases a rearrangement between non-sister chromatids (N-SCR) was found, whereas in the remaining 13 cases sister chromatids (SCR) were involved. Paternal and maternal origin (7:7) was found almost equally in cases with SCR (3:4) and N-SCR (4:3). In the cases with proven inversion, there was maternal and paternal origin in one case each. Twenty three out of 43 cytogenetically determined breakpoints correlated with common or rare fragile sites. In five cases, including all those with proven inverse orientation, all breakpoints corresponded to common or rare fragile sites. In at least two cases, one with an interstitial duplication (dup(19)(q11q13)) and one with a terminal duplication (dup(8) (p10p23)), concomitant deletions (del(8) (p23p23.3) and del(19)(q13q13)) were found.

The effect of hydroxyurea on rabbit subconjunctival fibroblast culture and use of hydroxyurea in rabbits after glaucoma filtration surgery

In an in vitro study, rabbit subconjunctival fibroblasts were cultured and the effects of an antineoplastic drug, hydroxyurea (HU), on fibroblast proliferation and fibroblast attachment was investigated. The effects of HU were compared with those of mitomycin C (MMC). Different concentrations of HU and MMC were added to culture medium. The HU doses which led to 50% of inhibition (ID(50)) and the dose which led to about 90% of inhibition (subtoxic high dose, STHD) were determined to be 8 and 1,000 microg/ml, respectively. ID(50) of MMC and its STHD which led to about 100% inhibition were found to be 0.01 and 1 microg/ml, respectively. Reversibility studies revealed that inhibition disappeared depending on the dose and incubation period of both HU and MMC. In an in vivo study, glaucoma filtration surgery (GFS) was performed in rabbits which were treated with HU (treatment group) and distilled water (control group). Tissue samples were taken from the subconjunctival area treated at 1 h, 1 day, 5 days and 30 days postoperatively. The biopsy specimens were then placed in tissue culture media. Fibroblast outgrowth rates detected in the HU group were found to be significantly lower than those in the control group in the specimens taken at the end of the first hour. The difference was significant on culture days 9-15 in the biopsy specimens taken on day 1 while it was not significant in those taken on days 5 and 30.