CTCF supports preferentially short lamina-associated domains.

More than one third of the mammalian genome is in a close association with the nuclear lamina, thus these genomic regions were termed lamina-associated domains (LADs). This association is fundamental for many aspects of chromatin biology including transcription, replication, and DNA damage repair. LADs association with the nuclear envelope is thought to be dependent on two major mechanisms: The first mechanism is the interaction between nuclear membrane proteins such as LBR with heterochromatin modifications that are enriched in LADs chromatin. The second mechanism is based on proteins that bind the borders of the LADs and support the association of the LADs with the nuclear envelope. Two factors were suggested to support the second mechanism: CCCTC-binding factor (CTCF) and YY1 based on their enriched binding to LADs borders. However, this mechanism has not been proven yet at a whole genome level. Here, to test if CTCF supports the LADs landscape, we generated melanoma cells with a partial loss of function (pLoF) of CTCF by the CRISPR-Cas9 system and determined the LADs landscape by lamin B ChIP-seq analysis. We found that under regular growth conditions, CTCF pLoF led to modest changes in the LADs landscape that included an increase in the signal of 2% of the LADs and a decrease in the signal of 8% of the LADs. However, CTCF importance for the LADs landscape was much higher upon induction of a chromatin stress. We induced chromatin stress by inhibiting RNA polymerase II, an intervention that is known to alter chromatin compaction and supercoiling. Notably, only in CTCF pLoF cells, the chromatin stress led to the dissociation of 7% of the LADs from the lamina. The CTCF-dependent LADs had almost three times shorter median length than the non-affected LADs, were enriched in CTCF binding at their borders, and were higher in their facultative-status (cell-type specific). Thus, it appears that CTCF is a key factor in facilitating the association of short facultative LADs with the nuclear lamina upon chromatin stress.

The non-responding adrenal metastasis in melanoma: The case for minimally invasive adrenalectomy in the age of modern therapies.

BACKGROUND: Minimally invasive adrenalectomy has facilitated resection of resistant adrenal metastases. The adrenal gland may function as a sanctuary site for metastatic growth despite systemic therapy. The objective of the study was to assess the outcomes of selective minimally invasive adrenalectomy during immunotherapy. METHODS: Candidates included patients with adrenal metastases resistant to systemic therapy who underwent minimally invasive adrenalectomy. RESULTS: There were 15 patients undergoing 16 minimally invasive adrenalectomies. Patients received either immunotherapy or BRAF inhibition prior to surgery. The mean operative time was 130 min with a median length of hospital stay of 2 days. At a median follow up of 24 months, 7 patients have no evidence of disease, 6 patients had progression with eventual mortality, while another patients has stable disease with maintenance therapy. One was lost to follow up. CONCLUSION: Despite an increase in objective durable responses in metastatic melanoma, there is still some site-specific resistance in isolated areas like the adrenal where early minimally invasive adrenalectomy remains indicated.

The Heterochromatin Landscape in Migrating Cells and the Importance of H3K27me3 for Associated Transcriptome Alterations.

H3K9me3, H3K27me3, and H4K20me1 are epigenetic markers associated with chromatin condensation and transcriptional repression. Previously, we found that migration of melanoma cells is associated with and dependent on global chromatin condensation that includes a global increase in these markers. Taken together with more recent reports by others suggests it is a general signature of migrating cells. Here, to learn about the function of these markers in migrating cells, we mapped them by ChIP-seq analysis. This analysis revealed that induction of migration leads to expansion of these markers along the genome and to an increased overlapping between them. Significantly, induction of migration led to a higher increase in H3K9me3 and H4K20me1 signals at repetitive elements than at protein-coding genes, while an opposite pattern was found for H3K27me3. Transcriptome analysis revealed 182 altered genes following induction of migration, of which 33% are dependent on H3K27me3 for these changes. H3K27me3 was also required to prevent changes in the expression of 501 other genes upon induction of migration. Taken together, our results suggest that heterochromatinization in migrating cells is global and not restricted to specific genomic loci and that H3K27me3 is a key component in executing a migration-specific transcriptional plan.

Long-Term (over 10 Years) Retrospective Follow-up of Laparoscopic Adjustable Gastric Banding.

BACKGROUND: Laparoscopic adjustable gastric banding (LAGB) placements have progressively decreased in recent years. This is related to poor long-term weight loss outcomes and necessity for revision or removal of these bands. Long-term outcome results following LAGB are limited. The aim of our study was to determine the long-term outcome after LAGB at our institution. OBJECTIVES: The aim of our study was to determine the long-term outcome after LAGB at our institution. SETTING: The setting of this is Academic Center, Israel. METHODS: Patients who underwent LAGB between 1999 and 2004 were reviewed. Patient comorbidities and weight loss parameters were collected preoperatively and at defined postoperative periods. Improvement in weight loss was defined as percent excess weight lost, and improvement in comorbidities was defined based on standardized reporting definitions. RESULTS: In total, 74 (80%) patients who underwent LAGB met inclusion criteria. The mean age at LAGB placement was 50.5 ± 9.6 years, and the mean body mass index (BMI) was 45.5 ± 4.8 kg/m2. Preoperative comorbidities were diabetes mellitus (13.5%), hypertension (32%), hyperlipidemia (12.1%), obstructive sleep apnea (5.4%), joints disease (10.8%), mood disorders (5.4%), and gastro-esophageal reflux disease (GERD) symptoms (8.1%). The mean follow-up was 162.96 ± 13.9 months; 44 patients (59.4%) had their band removed, and 22 (30%) had another bariatric surgery. The follow-up BMI was 35.7 ± 6.9 (p < 0.001), and the % total weight loss was 21.0 ± 0.13. There was no improvement in any of the comorbidities. GERD symptoms worsened at long-term follow-up (p < 0.001). Undergoing another bariatric procedure was associated with a higher weight loss (OR 12.8; CI 95% 1.62-23.9; p = 0.02). CONCLUSION: LAGB required removal in the majority of our patients and showed poor resolution of comorbidities with worsening of GERD-related symptoms. Patients who go on to have another bariatric procedure have more durable weight loss outcomes.

Correction to: Long-Term (over 10 Years) Retrospective Follow-up of Laparoscopic Adjustable Gastric Banding.

In the original article the spelling of author Naama Kafri was incorrect.

Toward the development of a novel non-RGD cyclic peptide drug conjugate for treatment of human metastatic melanoma.

The newly discovered short (9 amino acid) non-RGD S-S bridged cyclic peptide ALOS-4 (H-cycl(Cys-Ser-Ser-Ala-Gly-Ser-Leu-Phe-Cys)-OH), which binds to integrin αvß3 is investigated as peptide carrier for targeted drug delivery against human metastatic melanoma. ALOS4 binds specifically the αvß3 overexpressing human metastatic melanoma WM-266-4 cell line both in vitro and in ex vivo assays. Coupling ALOS4 to the topoisomerase I inhibitor Camptothecin (ALOS4-CPT) increases the cytotoxicity of CPT against human metastatic melanoma cells while reduces dramatically the cytotoxicity against non-cancerous cells as measured by the levels of γH2A.X, active caspase 3 and cell viability. Moreover, conjugating ALOS4 to CPT even increases the chemo-stability of CPT under physiological pH. Bioinformatic analysis using Rosetta platform revealed potential docking sites of ALOS4 on the αvß3 integrin which are distinct from the RGD binding sites. We propose to use this specific non-RGD cyclic peptide as the therapeutic carrier for conjugation of drugs in order to improve efficacy and reduce toxicity of currently available treatments of human malignant melanoma.