EMA Review of Panobinostat (Farydak) for the Treatment of Adult Patients with Relapsed and/or Refractory Multiple Myeloma

Therapeutic potential of targeting Nrf2 by panobinostat in pituitary neuroendocrine tumors

We aimed to identify the druggable cell-intrinsic vulnerabilities and target-based drug therapies for PitNETs using the high-throughput drug screening (HTS) and genomic sequencing methods. We examined 9 patient-derived PitNET primary cells in HTS. Based on the screening results, the potential target genes were analyzed with genomic sequencing from a total of 180 PitNETs. We identified and verified one of the most potentially effective drugs, which targeted the Histone deacetylases (HDACs) both in in vitro and in vivo PitNET models. Further RNA sequencing revealed underlying molecular mechanisms following treatment with the representative HDACs inhibitor, Panobinostat. The HTS generated a total of 20,736 single-agent dose responses which were enriched among multiple inhibitors for various oncogenic targets, including HDACs, PI3K, mTOR, and proteasome. Among these drugs, HDAC inhibitors (HDACIs) were, on average, the most potent drug class. Further studies using in vitro, in vivo, and isolated PitNET primary cell models validated HDACIs, especially Panobinostat, as a promising therapeutic agent. Transcriptional surveys revealed substantial alterations to the Nrf2 signaling following Panobinostat treatment. Moreover, Nrf2 is highly expressed in PitNETs. The combination of Panobinostat and Nrf2 inhibitor ML385 had a synergistic effect on PitNET suppression. The current study revealed a class of effective anti-PitNET drugs, HDACIs, based on the HTS and genomic sequencing. One of the representative compounds, Panobinostat, may be a potential drug for PitNET treatment via Nrf2-mediated redox modulation. Combination of Panobinostat and ML385 further enhance the effectiveness for PitNET treatment.

The Impact of Panobinostat on Cell Death in Combination with S63845 in Multiple Myeloma Cells

Multiple myeloma is a B cell neoplasm characterized by bone marrow infiltration with malignant plasma cells. The Overexpression of histone deacetylase prevents apoptosis of myeloma cells by different mechanisms. The combination of Panobinostat with a BH3 mimetic, S63845, has demonstrated significant antitumor activity in multiple myeloma. We examined the impact of Panobinostat combined with MCL-1 inhibitor on multiple myeloma cell lines in vivo and in vitro as well as on fresh human myeloma cells. Our study shows that MCL-1 remains a major resistant factor to cell death induced by Panobinostat. Therefore, the inhibition of the MCL-1 member is considered a therapeutic strategy to kill the myeloma cells. We examined that the MCL-1 inhibitor (S63845) enhanced the cytotoxic effect of Panobinostat and decreased the viability of human cell lines and primary myeloma patient cells. Mechanistically, Panobinostat/S63845 control cell death via an intrinsic pathway. Given these data, the combination can be a promising therapeutic target for myeloma patients and should be further explored in clinical trials.

Targeting Epigenetic Mechanisms: A Boon for Cancer Immunotherapy

Immunotherapy is rapidly emerging as a promising approach against cancer. In the last decade, various immunological mechanisms have been targeted to induce an increase in the immune response against cancer cells. However, despite promising results, many patients show partial response, resistance, or serious toxicities. A promising way to overcome this is the use of immunotherapeutic approaches, in combination with other potential therapeutic approaches. Aberrant epigenetic modifications play an important role in carcinogenesis and its progression, as well as in the functioning of immune cells. Thus, therapeutic approaches targeting aberrant epigenetic mechanisms and the immune response might provide an effective antitumor effect. Further, the recent development of potent epigenetic drugs and immunomodulators gives hope to this combinatorial approach. In this review, we summarize the synergy mechanism between epigenetic therapies and immunotherapy for the treatment of cancer, and discuss recent advancements in the translation of this approach.

A review on the treatment of multiple myeloma with small molecular agents in the past five years

Multiple myeloma is currently incurable, and the incidence rate is increasing year by year worldwide. Although in recent years the combined treatment plan based on proteasome inhibitors and immunomodulatory drugs has greatly improved the treatment effect of multiple myeloma, most patients still relapse and become resistant to current treatments. To solve this problem, scientists are committed to developing drugs with higher specificity, such as iberdomide, which is highly specific to ikaros and aiolos. This review aims to focus on the small molecular agents that are being researched/clinically used for the treatment of multiple myeloma, including the target mechanism, structure-activity relationship and application prospects of small molecular agents.

Novel PHD2/HDACs hybrid inhibitors protect against cisplatin-induced acute kidney injury

Acute kidney injury (AKI) is associated with high morbidity and mortality. Cisplatin is a common chemotherapeutic, but its nephrotoxicity-driven AKI limits its clinical application. Currently, there are no specific and satisfactory therapies in the clinic for AKI. Inhibitors of hypoxia-inducible factor prolyl hydroxylase 2 (HIF-PHD2) or histone deacetylase (HDACs) had shown renoprotective effects against AKI in preclinical studies. This study aimed to develop a novel therapeutic to prevent AKI progression by targeting PHD2 and HDACs simultaneously. We designed and synthesized a series of PHD2/HDACs hybrid inhibitors. The initial drug activity screening identified a candidate compound 31c, which exhibited potent inhibitory activities against PHD2 and HDAC1/2/6. Cellular analyses further showed that 31c did not affect cisplatin's antitumor activity in cancer cells but strongly protected cisplatin-induced toxicity on HK-2 cells. In vivo studies with the cisplatin-induced AKI mouse model demonstrated that 31c remarkably alleviated kidney dysfunction with suppressed plasma BUN/SCr and increased EPO levels. The potent renoprotective effects of 31c on AKI were confirmed by significant improvements in pathological kidney conditions in the mouse model. These results suggest that the novel PHD2/HDACs hybrid inhibitor, 31c, has a clinical potential as the renoprotective agent for the treatment/prevention of cisplatin-induced AKI for various cancers.

Expression of histone deacetylase (HDAC) family members in bortezomib-refractory multiple myeloma and modulation by panobinostat

AIM

Multiple myeloma (MM) is a hematological malignancy of antibody-producing mature B cells or plasma cells. The proteasome inhibitor, bortezomib, was the first-in-class compound to be FDA approved for MM and is frequently utilized in induction therapy. However, bortezomib refractory disease is a major clinical concern, and the efficacy of the pan-histone deacetylase inhibitor (HDACi), panobinostat, in bortezomib refractory disease indicates that HDAC targeting is a viable strategy. Here, we utilized isogenic bortezomib resistant models to profile HDAC expression and define baseline and HDACi-induced expression patterns of individual HDAC family members in sensitive vs. resistant cells to better understanding the potential for targeting these enzymes.

METHODS

Gene expression of HDAC family members in two sets of isogenic bortezomib sensitive or resistant myeloma cell lines was examined. These cell lines were subsequently treated with HDAC inhibitors: panobinostat or vorinostat, and HDAC expression was evaluated. CRISPR/Cas9 knockdown and pharmacological inhibition of specific HDAC family members were conducted.

RESULTS

Interestingly, HDAC6 and HDAC7 were significantly upregulated and downregulated, respectively, in bortezomib-resistant cells. Panobinostat was effective at inducing cell death in these lines and modulated HDAC expression in cell lines and patient samples. Knockdown of HDAC7 inhibited cell growth while pharmacologically inhibiting HDAC6 augmented cell death by panobinostat.

CONCLUSION

Our data revealed heterogeneous expression of individual HDACs in bortezomib sensitive vs. resistant isogenic cell lines and patient samples treated with panobinostat. Cumulatively our findings highlight distinct roles for HDAC6 and HDAC7 in regulating cell death in the context of bortezomib resistance.

New Multi-Targeted Antiproliferative Agents: Design and Synthesis of IC261-Based Oxindoles as Potential Tubulin, CK1 and EGFR Inhibitors

A series of 3-benzylideneindolin-2-one compounds was designed and synthesized based on combretastatin A-4 and compound IC261, a dual casein kinase (CK1)/tubulin polymerization inhibitor, taking into consideration the pharmacophore required for EGFR-tyrosine kinase inhibition. The new molecular entities provoked significant growth inhibition against PC-3, MCF-7 and COLO-205 at a 10 μM dose. Compounds 6-chloro-3-(2,4,6-trimethoxybenzylidene) indolin-2-one, 4b, and 5-methoxy-3-(2,4,6-trimethoxybenzylidene)indolin-2-one, 4e, showed potent activity against the colon cancer COLO-205 cell line with an IC50 value of 0.2 and 0.3 μM. A mechanistic study demonstrated 4b's efficacy in inhibiting microtubule assembly (IC50 = 1.66 ± 0.08 μM) with potential binding to the colchicine binding site (docking study). With an IC50 of 1.92 ± 0.09 μg/mL, 4b inhibited CK1 almost as well as IC261. Additionally, 4b and 4e were effective inhibitors of EGFR-TK with IC50s of 0.19 μg/mL and 0.40 μg/mL compared to Gifitinib (IC50 = 0.05 μg/mL). Apoptosis was induced in COLO-205 cells treated with 4b, with apoptotic markers dysregulated. Caspase 3 levels were elevated to more than three-fold, while Cytochrome C levels were doubled. The cell cycle was arrested in the pre-G1 phase with extensive cellular accumulation in the pre-G1 phase, confirming apoptosis induction. Levels of cell cycle regulating proteins BAX and Bcl-2 were also defective. The binding interaction patterns of these compounds at the colchicine binding site of tubulin and the Gifitinib binding site of EGFR were verified by molecular docking, which adequately matched the reported experimental result. Hence, 4b and 4e are considered promising potent multitarget agents against colon cancer that require optimization.

Targeted therapy of multiple myeloma

Multiple myeloma (MM) is a malignant proliferative disease of monoclonal plasma cells (PCs) and is characterized by uncontrolled proliferation of PCs and excessive production of specific types of immunoglobulins. Since PCs are terminally differentiated B cells, the World Health Organization (WHO) classifies MM as lymphoproliferative B-cell disease. The incidence of MM is 6-7 cases per 100,000 people in the world every year and the second most common cancer in the blood system. Due to the effects of drug resistance and malignant regeneration of MM cells in the microenvironment, all current treatment methods can prolong both overall and symptom-free survival rates of patients with MM but cannot cure MM. Both basic and clinical studies have proven that targeted therapy leads to a clear and significant prolongation of the survival of patients with MM, but when the disease recurs again, resistance to the previous treatment will occur. Therefore, the discovery of new targets and treatment methods plays a vital role in the treatment of MM. This article introduces and summarizes targeted MM therapy, potential new targets, and future precision medicine in MM.

Advances in the Treatment of Relapsed and Refractory Multiple Myeloma in Patients with Renal Insufficiency: Novel Agents, Immunotherapies and Beyond

BACKGROUND

Renal insufficiency is one of the most frequent complications in multiple myeloma. The incidence of renal insufficiency in patients with multiple myeloma ranges from 20% to 50%. Renal impairment in patients with multiple myeloma results primarily from the toxic effects of monoclonal light chains on the kidneys. Dehydration, hypercalcemia, hyperuricemia, the application of nephrotoxic NSARs, antibiotics, contrast agents, etc., all play a major role in the deterioration of renal function in patients with multiple myeloma. The diagnosis and treatment of these patients use an interdisciplinary approach in consultation with hematologist-oncologists, radiologists, nephrologists and intensive care specialists. Using new drugs in the treatment of patients with refractory/relapsed multiple myeloma and renal insufficiency markedly improves progression-free survival and overall survival in these patients.

CONCLUSIONS

New drugs have helped to widen the treatment options available for patients with renal impairment and refractory/relapsed multiple myeloma, since dose adjustments are unnecessary with carfilzomib as well as with panobinostat, elotuzumab, pomalidomide or daratumumab in patients with renal impairment. Several new substances for the treatment of refractory/relapsed multiple myeloma have been approved in the meantime, including belantamab mafodotin, selinexor, melflufen, venetoclax, CAR T-cell therapy and checkpoint inhibitors. Ongoing studies are investigating their administration in patients with renal impairment.

The Role of Allogeneic Stem Cell Transplantation in Multiple Myeloma: A Systematic Review of the Literature

Multiple myeloma (MM) is an indolent B-cell malignancy, where treatment is aimed at preventing organ dysfunction from light chain accumulation (slowing disease progression) and inducing remission. Allogeneic stem cell transplant (allo-SCT), through graft versus myeloma (GVM) effects, has the potential to induce remission to a potentially curative-like state. In this systematic review, we aimed to understand this relationship to the risks and severity of disease in categorized patients and gain an updated comprehension of the future of allo-SCT in MM treatment. We conducted this review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and searched the PubMed database to obtain the specified literature with both the use of keywords and Medical Subject Headings (MeSH). A total of 16 relevant articles were included for discussion after the quality appraisal was completed, as appropriate, by either the Cochrane tool or Newcastle-Ottawa checklist. Our review concludes that while allo-SCT may benefit high-risk patients, successful procedures may incorporate a tandem autologous hematopoietic stem cell transplant approach in combination with novel pharmacologic contributions for which there is an observed synergy in the modulation of the immunologic microenvironment. Furthermore, tailored patient selection by evaluating pre-transplant factors including high-risk cytogenetics, age, and pre-salvage International Staging System (ISS) can predict post-transplantation success including non-relapse mortality. Successive research should continue to revise and update treatment options as the evolving therapeutic drug regimens may change over the course of indolent disease.

Drugs and Epigenetic Molecular Functions. A Pharmacological Data Scientometric Analysis

Interactions of drugs with the classical epigenetic mechanism of DNA methylation or histone modification are increasingly being elucidated mechanistically and used to develop novel classes of epigenetic therapeutics. A data science approach is used to synthesize current knowledge on the pharmacological implications of epigenetic regulation of gene expression. Computer-aided knowledge discovery for epigenetic implications of current approved or investigational drugs was performed by querying information from multiple publicly available gold-standard sources to (i) identify enzymes involved in classical epigenetic processes, (ii) screen original biomedical scientific publications including bibliometric analyses, (iii) identify drugs that interact with epigenetic enzymes, including their additional non-epigenetic targets, and (iv) analyze computational functional genomics of drugs with epigenetic interactions. PubMed database search yielded 3051 hits on epigenetics and drugs, starting in 1992 and peaking in 2016. Annual citations increased to a plateau in 2000 and show a downward trend since 2008. Approved and investigational drugs in the DrugBank database included 122 compounds that interacted with 68 unique epigenetic enzymes. Additional molecular functions modulated by these drugs included other enzyme interactions, whereas modulation of ion channels or G-protein-coupled receptors were underrepresented. Epigenetic interactions included (i) drug-induced modulation of DNA methylation, (ii) drug-induced modulation of histone conformations, and (iii) epigenetic modulation of drug effects by interference with pharmacokinetics or pharmacodynamics. Interactions of epigenetic molecular functions and drugs are mutual. Recent research activities on the discovery and development of novel epigenetic therapeutics have passed successfully, whereas epigenetic effects of non-epigenetic drugs or epigenetically induced changes in the targets of common drugs have not yet received the necessary systematic attention in the context of pharmacological plasticity.

Inactivation of the Akt/FOXM1 Signaling Pathway by Panobinostat Suppresses the Proliferation and Metastasis of Gastric Cancer Cells

Gastric cancer is the fifth most common cancer and the third leading cause of cancer-related deaths worldwide. Histone deacetylase (HDAC) inhibitors are a new class of cytostatic agents available for the treatment of various cancers and diseases. Although numerous clinical and pre-clinical trials on the anticancer effects of panobinostat have been conducted, only a few reports have investigated its efficacy in gastric cancer. The present study aimed to investigate the effects of panobinostat in gastric cancer cells. Panobinostat significantly inhibited the cell viability and proliferation of the gastric cancer cell lines SNU484 and SNU638 in a dose-dependent manner; it reduced the colony-forming ability of these cells. Moreover, it induced apoptosis as indicated by increased protein levels of cleaved poly ADP-ribose polymerase and cleaved caspase-3. Panobinostat induced the G2/M cell cycle arrest in SNU484 and SNU638 cells and subsequently decreased the G2/M phase regulatory-associated protein expression of p-Wee1, Myt1, and Cdc2. Furthermore, panobinostat significantly inhibited the metastasis of SNU484 and SNU638 cells by regulating the expression of MMP-9 and E-cadherin. Further, it decreased the protein levels of p-Akt and forkhead box protein M1 (FOXM1). These effects were reversed by the Akt agonist SC79 and were accelerated by the Akt inhibitor LY2940002. Moreover, tumor growth in xenograft animal experiments was suppressed by panobinostat. These results indicated that panobinostat inhibits the proliferation, metastasis, and cell cycle progression of gastric cancer cells by promoting apoptosis and inactivating Akt/FOXM1 signaling. Cumulatively, our present study suggests that panobinostat is a potential drug for the treatment of gastric cancer.

Epigenetics of cutaneous T-cell lymphoma: biomarkers and therapeutic potentials

Cutaneous T-cell lymphomas (CTCLs) are a heterogeneous group of skin-homing non-Hodgkin lymphomas. There are limited options for effective treatment of patients with advanced-stage CTCL, leading to a poor survival rate. Epigenetics plays a pivotal role in regulating gene expression without altering the DNA sequence. Epigenetic alterations are involved in virtually all key cancer-associated pathways and are fundamental to the genesis of cancer. In recent years, the epigenetic hallmarks of CTCL have been gradually elucidated and their potential values in the diagnosis, prognosis, and therapeutic intervention have been clarified. In this review, we summarize the current knowledge of the best-studied epigenetic modifications in CTCL, including DNA methylation, histone modifications, microRNAs, and chromatin remodelers. These epigenetic regulators are essential in the development of CTCL and provide new insights into the clinical treatments of this refractory disease.

Histone Deacetylase Inhibitors as Therapeutic Interventions on Cervical Cancer Induced by Human Papillomavirus

The role of epigenetic modifications on the carcinogenesis process has received a lot of attention in the last years. Among those, histone acetylation is a process regulated by histone deacetylases (HDAC) and histone acetyltransferases (HAT), and it plays an important role in epigenetic regulation, allowing the control of the gene expression. HDAC inhibitors (HDACi) induce cancer cell cycle arrest, differentiation, and cell death and reduce angiogenesis and other cellular events. Human papillomaviruses (HPVs) are small, non-enveloped double-stranded DNA viruses. They are major human carcinogens, being intricately linked to the development of cancer in 4.5% of the patients diagnosed with cancer worldwide. Long-term infection of high-risk (HR) HPV types, mainly HPV16 and HPV18, is one of the major risk factors responsible for promoting cervical cancer development. In vitro and in vivo assays have demonstrated that HDACi could be a promising therapy to HPV-related cervical cancer. Regardless of some controversial studies, the therapy with HDACi could target several cellular targets which HR-HPV oncoproteins could be able to deregulate. This review article describes the role of HDACi as a possible intervention in cervical cancer treatment induced by HPV, highlighting the main advances reached in the last years and providing insights for further investigations regarding those agents against cervical cancer.

A phase I study of panobinostat in children with relapsed and refractory hematologic malignancies

Background: Panobinostat demonstrates activity against pediatric cancers in vitro. A phase I trial in children with refractory hematologic malignancies was conducted. Study design: The trial evaluated two schedules of oral panobinostat using 3 + 3 dose escalations in 28-day cycles. For children with leukemia, panobinostat was given once daily three days a week each week at 24, 30 and 34 mg/m2/day. For children with lymphoma, panobinostat was given once daily three days a week every other week at 16, 20 and 24 mg/m2/day. Cerebrospinal fluid (CSF) from Day 29 of the first cycle, when available, was evaluated for PK. The study was registered on clinicaltrials.gov (NCT01321346) Results: Twenty-two subjects enrolled with leukemia. Five enrolled at dose level 1, 6 at dose level 2, and 11 at dose level 3. There was one dose limiting toxicity (DLT) in the leukemia arm at dose level 3 (Grade 4 hypertriglyceridemia), but no maximum tolerated dose (MTD) was identified. No subjects required removal from protocol therapy for QTc prolongation. PK studies were available in 11 subjects with similar exposure in children as in adults. Four Day 29 CSF specimens were found to have panobinostat levels below the lower limit of quantification. Five subjects with lymphoma were enrolled and received study drug, and 4 were evaluable for DLT. A DLT was reported (Grade 3 enteritis) on the lymphoma arm. Conclusions: Panobinostat was tolerated in heavily pretreated pediatric subjects. Gastrointestinal effects were observed on this study. There were no cardiac findings. There were no responses.

Efficacy of Panobinostat for the Treatment of Multiple Myeloma

Panobinostat represents a potent oral nonselective pan-histone deacetylase inhibitor (HDAC) with activity in myeloma patients. It has been approved by the FDA and EMA in combination with bortezomib and dexamethasone for the treatment of multiple myeloma, in patients who have received at least two prior regimens, including bortezomib and an immunomodulatory agent. In order to further explore its clinical potential, it is evaluated in different combinations in relapsed/refractory and newly diagnosed multiple myeloma. This review focuses on available data about panobinostat's pharmacology and its role in clinical practice. This review will reveal panobinostat's efficacy as antimyeloma treatment, describing drug evolution from preclinical experimental administration to administration in phase III trials, which established its role in current clinical practice. Based on the latest data, we will present its mechanism of action, its efficacy, and most important issues regarding its toxicity profile. We will further try to shed light on its role in current and future therapeutic landscape of myeloma patients. Panobinostat retains its role in therapy of multiple myeloma because of its manageable toxicity profile and its efficacy, mainly in heavily pretreated multiple myeloma patients. These characteristics make it valuable also for novel regimens in combination with second-generation proteasome inhibitors, IMiDs, and monoclonal antibodies. Results of ongoing trials are expected to shed light on drug introduction in different therapeutic combinations or even at an earlier level of disease course.

New generation drugs for treatment of multiple myeloma

Multiple myeloma (MM), a plasma cell malignancy, is characterised by lesions in multiple bones involving transformed, matured post-follicular B cells. The course of the disease involves an initial development of monoclonal gammopathy of undetermined significance (MGUS), followed by smouldering MM, before the full MM disease emerges. Despite novel therapies, MM remains incurable, managed by combination therapies, including proteasome inhibitors (PIs), immunomodulators (IMiDs) and anti-human CD38 (daratumumab). MM patients have an increased risk of thromboembolic events due to combination treatments with IMiDs, PIs and anti-human CD38 antibody, and steroids. This review will examine the efficacy and pro-thrombotic effects of MM therapies.

Cellular Senescence and the Kidney: Potential Therapeutic Targets and Tools

Chronic kidney disease (CKD) is an increasing health burden (affecting approximately 13.4% of the population). Currently, no curative treatment options are available and treatment is focused on limiting the disease progression. The accumulation of senescent cells has been implicated in the development of kidney fibrosis by limiting tissue rejuvenation and through the secretion of pro-fibrotic and pro-inflammatory mediators termed as the senescence-associated secretory phenotype. The clearance of senescent cells in aging models results in improved kidney function, which shows promise for the options of targeting senescent cells in CKD. There are several approaches for the development of “senotherapies”, the most rigorous of which is the elimination of senescent cells by the so-called senolytic drugs either newly developed or repurposed for off-target effects in terms of selectively inducing apoptosis in senescent cells. Several chemotherapeutics and checkpoint inhibitors currently used in daily oncological practice show senolytic properties. However, the applicability of such senolytic compounds for the treatment of renal diseases has hardly been investigated. A serious concern is that systemic side effects will limit the use of senolytics for kidney fibrosis. Specifically targeting senescent cells and/or targeted drug delivery to the kidney might circumvent these side effects. In this review, we discuss the connection between CKD and senescence, the pharmacological options for targeting senescent cells, and the means to specifically target the kidney.

Class I-Histone Deacetylase (HDAC) Inhibition is Superior to pan-HDAC Inhibition in Modulating Cisplatin Potency in High Grade Serous Ovarian Cancer Cell Lines

High grade serous ovarian cancer (HGSOC) is the most common and aggressive ovarian cancer subtype with the worst clinical outcome due to intrinsic or acquired drug resistance. Standard treatment involves platinum compounds. Cancer development and chemoresistance is often associated with an increase in histone deacetylase (HDAC) activity. The purpose of this study was to examine the potential of HDAC inhibitors (HDACi) to increase platinum potency in HGSOC. Four HGSOC cell lines with different cisplatin sensitivity were treated with combinations of cisplatin and entinostat (class I HDACi), panobinostat (pan-HDACi), or nexturastat A (class IIb HDACi), respectively. Inhibition of class I HDACs by entinostat turned out superior in increasing cisplatin potency than pan-HDAC inhibition in cell viability assays (MTT), apoptosis induction (subG1), and caspase 3/7 activation. Entinostat was synergistic with cisplatin in all cell lines in MTT and caspase activation assays. MTT assays gave combination indices (CI values) < 0.9 indicating synergism. The effect of HDAC inhibitors could be attributed to the upregulation of pro-apoptotic genes (CDNK1A, APAF1, PUMA, BAK1) and downregulation of survivin. In conclusion, the combination of entinostat and cisplatin is synergistic in HGSOC and could be an effective strategy for the treatment of aggressive ovarian cancer.

Histone Deacetylase Inhibitors Sensitize TRAIL-Induced Apoptosis in Colon Cancer Cells

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is considered as a promising anti-cancer therapeutic. However, many cancers have been found to be or to become inherently resistant to TRAIL. A combination of epigenetic modifiers, such as histone deacetylase inhibitors (HDACi's), with TRAIL was effective to overcome TRAIL resistance in some cancers. Broad spectrum HDACi's, however, show considerable toxicity constraining clinical use. Since overexpression of class I histone deacetylase (HDAC) has been found in colon tumors relative to normal mucosa, we have focused on small spectrum HDACi's. We have now tested agonistic receptor-specific TRAIL variants rhTRAIL 4C7 and DHER in combination with several class I specific HDACi's on TRAIL-resistant colon cancer cells DLD-1 and WiDr. Our data show that TRAIL-mediated apoptosis is largely improved in WiDr cells by pre-incubation with Entinostat-a HDAC1, 2, and 3 inhibitor- and in DLD-1 cells by RGFP966-a HDAC3-specific inhibitor- or PCI34051-a HDAC8-specific inhibitor. We are the first to report that using RGFP966 or PCI34051 in combination with rhTRAIL 4C7 or DHER represents an effective cancer therapy. The intricate relation of HDACs and TRAIL-induced apoptosis was confirmed in cells by knockdown of HDAC1, 2, or 3 gene expression, which showed more early apoptotic cells upon adding rhTRAIL 4C7 or DHER. We observed that RGFP966 and PCI34051 increased DR4 expression after incubation on DLD-1 cells, while RGFP966 induced more DR5 expression on WiDr cells, indicating a different role for DR4 or DR5 in these combinations. At last, we show that combined treatment of RGFP966 with TRAIL variants (rhTRAIL 4C7/DHER) increases apoptosis on 3D tumor spheroid models.

De novo mutations in MSL3 cause an X-linked syndrome marked by impaired histone H4 lysine 16 acetylation

The etiological spectrum of ultra-rare developmental disorders remains to be fully defined. Chromatin regulatory mechanisms maintain cellular identity and function, where misregulation may lead to developmental defects. Here, we report pathogenic variations in MSL3, which encodes a member of the chromatin-associated male-specific lethal (MSL) complex responsible for bulk histone H4 lysine 16 acetylation (H4K16ac) in flies and mammals. These variants cause an X-linked syndrome affecting both sexes. Clinical features of the syndrome include global developmental delay, progressive gait disturbance, and recognizable facial dysmorphism. MSL3 mutations affect MSL complex assembly and activity, accompanied by a pronounced loss of H4K16ac levels in vivo. Patient-derived cells display global transcriptome alterations of pathways involved in morphogenesis and cell migration. Finally, we use histone deacetylase inhibitors to rebalance acetylation levels, alleviating some of the molecular and cellular phenotypes of patient cells. Taken together, we characterize a syndrome that allowed us to decipher the developmental importance of MSL3 in humans.

Monoclonal Antibodies and Multiple Myeloma: All in All It's Just Another Brick in the Wall?

This commentary offers insight about the recent review by the European Medicines Agency on the approval of daratumumab for the treatment of adult patients with multiple myeloma.

Panobinostat and Multiple Myeloma in 2018

FDA and EMA approval of panobinostat offers an additional therapeutic option for multiple myeloma; however, adoption of panobinostat has been limited by its adverse event profile. Trials are ongoing to optimize the dosing of panobinostat and to identify its best partners, in order to fully realize the potential of this drug class.