Targeted therapy in haematological malignancies

A decade of approved first-in-class small molecule orphan drugs: Achievements, challenges and perspectives

In the past decade (2011-2020), there was a growing interest in the discovery and development of orphan drugs for the treatment of rare diseases. However, rare diseases only account for a population of 0.65‰-1‰ which usually occur with previously unknown biological mechanisms and lack of specific therapeutics, thus to increase the demands for the first-in-class (FIC) drugs with new biological targets or mechanisms. Considering the achievements in the past 10 years, a total of 410 drugs were approved by U.S. Food and Drug Administration (FDA), which contained 151 FIC drugs and 184 orphan drugs, contributing to make up significant numbers of the approvals. Notably, more than 50% of FIC drugs are developed as orphan drugs and some of them have already been milestones in drug development. In this review, we aim to discuss the FIC small molecules for the development of orphan drugs case by case and highlight the R&D strategy with novel targets and scientific breakthroughs.

Biomicrofluidic Systems for Hematologic Cancer Research and Clinical Applications

A persistent challenge in developing personalized treatments for hematologic cancers is the lack of patient specific, physiologically relevant disease models to test investigational drugs in clinical trials and to select therapies in a clinical setting. Biomicrofluidic systems and organ-on-a-chip technologies have the potential to change how researchers approach the fundamental study of hematologic cancers and select clinical treatment for individual patient. Here, we review microfluidics cell-based technology with application toward studying hematologic tumor microenvironments (TMEs) for the purpose of drug discovery and clinical treatment selection. We provide an overview of state-of-the-art microfluidic systems designed to address questions related to hematologic TMEs and drug development. Given the need to develop personalized treatment platforms involving this technology, we review pharmaceutical drugs and different modes of immunotherapy for hematologic cancers, followed by key considerations for developing a physiologically relevant microfluidic companion diagnostic tool for mimicking different hematologic TMEs for testing with different drugs in clinical trials. Opportunities lie ahead for engineers to revolutionize conventional drug discovery strategies of hematologic cancers, including integrating cell-based microfluidics technology with machine learning and automation techniques, which may stimulate pharma and regulatory bodies to promote research and applications of microfluidics technology for drug development.

A novel approach for medical research on lymphomas: A study validation of claims-based algorithms to identify incident cases

The use of claims database to study lymphomas in real-life conditions is a crucial issue in the future. In this way, it is essential to develop validated algorithms for the identification of lymphomas in these databases. The aim of this study was to assess the validity of diagnosis codes in the French health insurance database to identify incident cases of lymphomas according to results of a regional cancer registry, as the gold standard.Between 2010 and 2013, incident lymphomas were identified in hospital data through 2 algorithms of selection. The results of the identification process and characteristics of incident lymphomas cases were compared with data from the Tarn Cancer Registry. Each algorithm's performance was assessed by estimating sensitivity, predictive positive value, specificity (SPE), and negative predictive value.During the period, the registry recorded 476 incident cases of lymphomas, of which 52 were Hodgkin lymphomas and 424 non-Hodgkin lymphomas. For corresponding area and period, algorithm 1 provides a number of incident cases close to the Registry, whereas algorithm 2 overestimated the number of incident cases by approximately 30%. Both algorithms were highly specific (SPE = 99.9%) but moderately sensitive. The comparative analysis illustrates that similar distribution and characteristics are observed in both sources.Given these findings, the use of claims database can be consider as a pertinent and powerful tool to conduct medico-economic or pharmacoepidemiological studies in lymphomas.

Targeting the Akt, GSK-3, Bcl-2 axis in acute myeloid leukemia

Over the last few decades, there has been significant progress in the understanding of the pathogenetic mechanisms of the Acute Myeloid Leukemia (AML). However, despite important advances in elucidating molecular mechanisms, the treatment of AML has not improved significantly, remaining anchored at the standard chemotherapy regimen "3 + 7", with the prognosis of patients remaining severe, especially for the elderly and for those not eligible for transplant procedures. The biological and clinical heterogeneity of AML represents the major obstacle that hinders the improvement of prognosis and the identification of new effective therapeutic approaches. To date, abundant information has been collected on the genetic and molecular alterations of AML carrying prognostic significance. However, not enough is known on how AML progenitors regulate proliferation and survival by redundant and cross-talking signal transduction pathways (STP). Furthermore, it remains unclear how such complicated network affects prognosis and therapeutic treatment options, although many of these molecular determinants are potentially attractive for their druggable characteristics. In this review, some of the key STP frequently deregulated in AML, such as PI3k/Akt/mTOR pathway, GSK3 and components of Bcl-2 family of proteins, are summarized, highlighting in addition their interplay. Based on this information, we reviewed new targeted therapeutic approaches, focusing on the aberrant networks that sustain the AML blast proliferation, survival and drug resistance, aiming to improve disease treatment. Finally, we reported the approaches aimed at disrupting key signaling cross-talk overcoming resistances based on the combination of different targeting therapeutic strategies.

Immunohistochemical evaluation of ROCK activation in invasive breast cancer

BACKGROUND

Two isoforms of Rho-associated coiled-coil kinase (ROCK), ROCKI and ROCKII, play an important role in many cellular processes. Despite the accumulating evidence showing that ROCK could be a potential cancer therapeutic target, the relevant tumor types to ROCK activation are not well clarified. The aim of this study was to evaluate the ROCK activation status in different tumor types of breast cancer.

RESULTS

We evaluated the immunoreactivities of phosphorylation-specific antibodies of ROCKI and ROCKII to inform their kinase activation in 275 of breast carcinoma tissues, including 56 of carcinoma in situ, 116 of invasive carcinoma, and 103 of invasive carcinoma with metastasis. ROCKII activation signal detected in nucleus was significantly correlated with tumor metastasis, while ROCKI and cytosolic ROCKII activation signals made no significant difference in that metastasis. Furthermore, nuclear ROCKII activation signal was associated with poor clinical outcome and correlated with late tumor stage, low expression of estrogen receptor (ER) and progesterone receptor (PR), overexpression of human epidermal growth factor receptor 2 (HER2) and high Ki67 labeling index.

CONCLUSIONS

Nuclear ROCKII activation signal might contribute to the tumor metastasis in breast cancer. Differences in ROCK activation that underlie the phenotypes of breast cancer could enhance our understanding for the use of ROCK inhibitors in cancer therapy.

Primary Diffuse Large B-cell Lymphoma involving the Mandible

Lymphomas of the oral cavity are rare and typically present as intraosseous lesions that are most commonly diffuse large B-cell type. Diffuse large B-cell lymphoma (DLBCL) is an aggressive B-cell lymphoma histologically characterized by diffuse proliferation of large neoplastic B-lymphoid cells with a nuclear size equal to or exceeding normal histiocytic nuclei. A case of DLBCL of the mandible in an 18 years old male patient is presented. This report discusses this rare malignancy, including clinical presentation, histopathologic features, immunologic profile, treatment and prognosis. Though lymphoma of mandible is rare, it must be considered in differential diagnosis of swellings arising in the region.

What are the barriers of quality survivorship care for haematology cancer patients? Qualitative insights from cancer nurses

PURPOSE

Many haematological cancer survivors report long-term physiological and psychosocial effects beyond treatment completion. These survivors continue to experience impaired quality of life (QoL) as a result of their disease and aggressive treatment. As key members of the multidisciplinary team, the purpose of this study is to examine the insights of cancer nurses to inform future developments in survivorship care provision.

METHODS

Open text qualitative responses from two prospective Australian cross-sectional surveys of nurses (n = 136) caring for patients with haematological cancer. Data were analysed thematically, using an inductive approach to identify themes.

RESULTS

This study has identified a number of issues that nurses perceive as barriers to quality survivorship care provision. Two main themes were identified: the first relating to the challenges nurses face in providing care ('care challenges') and the second relating to the challenges of providing survivorship care within contemporary health care systems ('system challenges').

CONCLUSIONS

Cancer nurses perceive the nature of haematological cancer and its treatment and of the health care system itself, as barriers to the provision of quality survivorship care. Care challenges such as the lack of a standard treatment path and the relapsing or remitting nature of haematological cancers may be somewhat intractable, but system challenges relating to clearly defining and delineating professional responsibilities and exchanging information with other clinicians are not.

IMPLICATIONS FOR CANCER SURVIVORS

Addressing the issues identified will facilitate cancer nurses' provision of survivorship care and help address haematological survivors' needs with regard to the physical and psychosocial consequences of their cancer and treatment.

Taxonomy of breast cancer based on normal cell phenotype predicts outcome

Accurate classification is essential for understanding the pathophysiology of a disease and can inform therapeutic choices. For hematopoietic malignancies, a classification scheme based on the phenotypic similarity between tumor cells and normal cells has been successfully used to define tumor subtypes; however, use of normal cell types as a reference by which to classify solid tumors has not been widely emulated, in part due to more limited understanding of epithelial cell differentiation compared with hematopoiesis. To provide a better definition of the subtypes of epithelial cells comprising the breast epithelium, we performed a systematic analysis of a large set of breast epithelial markers in more than 15,000 normal breast cells, which identified 11 differentiation states for normal luminal cells. We then applied information from this analysis to classify human breast tumors based on normal cell types into 4 major subtypes, HR0-HR3, which were differentiated by vitamin D, androgen, and estrogen hormone receptor (HR) expression. Examination of 3,157 human breast tumors revealed that these HR subtypes were distinct from the current classification scheme, which is based on estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2. Patient outcomes were best when tumors expressed all 3 hormone receptors (subtype HR3) and worst when they expressed none of the receptors (subtype HR0). Together, these data provide an ontological classification scheme associated with patient survival differences and provides actionable insights for treating breast tumors.

Rho-associated kinases in tumorigenesis: re-considering ROCK inhibition for cancer therapy

The Rho-associated (ROCK) serine/threonine kinases have emerged as central regulators of the actomyosin cytoskeleton, their main purpose being to promote contractile force generation. Aided by the discovery of effective inhibitors such as Y27632, their roles in cancer have been extensively explored with particular attention focused on motility, invasion and metastasis. Recent studies have revealed a surprisingly diverse range of functions of ROCK. These insights could change the way ROCK inhibitors might be used in cancer therapy to include the targeting of stromal rather than tumour cells, the concomitant blocking of ROCK and proteasome activity in K-Ras-driven lung cancers and the combination of ROCK with tyrosine kinase inhibitors for treating haematological malignancies such as chronic myeloid leukaemia. Despite initial optimism for therapeutic efficacy of ROCK inhibition for cancer treatment, no compounds have progressed into standard therapy so far. However, by carefully defining the key cancer types and expanding the appreciation of ROCK's role in cancer beyond being a cell-autonomous promoter of tumour cell invasion and metastasis, the early promise of ROCK inhibitors for cancer therapy might still be realized.

The development of immune-modulating compounds to disrupt HIV latency

Antiretroviral therapy (ART) has proved highly effective in suppressing HIV-1 replication and disease progression. Nevertheless, ART has failed to eliminate the virus from infected individuals. The main obstacle to HIV-1 eradication is the persistence of cellular viral reservoirs. Therefore, the "shock-and-kill" strategy was proposed consisting of inducing HIV-1 escape from latency, in the presence of ART. This is followed by the elimination of reactivated, virus-producing cells. Immune modulators, including protein kinase C (PKC) activators, anti-leukemic drugs and histone deacetylase inhibitors (HDACis) have all demonstrated efficacy in the reactivation of latent virus replication. This review will focus on the potential use of these small molecules in the "shock and kill" strategy, the molecular basis for their action and the potential advantages of their immune-modulating activities.

BCR-ABL1 tyrosine kinase sustained MECOM expression in chronic myeloid leukaemia

MECOM oncogene expression correlates with chronic myeloid leukaemia (CML) progression. Here we show that the knockdown of MECOM (E) and MECOM (ME) isoforms reduces cell division at low cell density, inhibits colony-forming cells by 34% and moderately reduces BCR-ABL1 mRNA and protein expression but not tyrosine kinase catalytic activity in K562 cells. We also show that both E and ME are expressed in CD34(+) selected cells of both CML chronic phase (CML-CP), and non-CML (normal) origin. Furthermore, MECOM mRNA and protein expression were repressed by imatinib mesylate treatment of CML-CP CD34(+) cells, K562 and KY01 cell lines whereas imatinib had no effect in non-CML BCR-ABL1 -ve CD34(+) cells. Together these results suggest that BCR-ABL1 tyrosine kinase catalytic activity regulates MECOM gene expression in CML-CP progenitor cells and that the BCR-ABL1 oncoprotein partially mediates its biological activity through MECOM. MECOM gene expression in CML-CP progenitor cells would provide an in vivo selective advantage, contributing to CML pathogenesis.

A review on various targeted anticancer therapies

Translational oncology aims to translate laboratory research into new anticancer therapies. Contrary to conventional surgery, chemotherapy, and radiotherapy, targeted anticancer therapy (TAT) refers to systemic administration of drugs with particular mechanisms that specifically act on well-defined targets or biologic pathways that, when activated or inactivated, may cause regression or destruction of the malignant process, meanwhile with minimized adverse effects on healthy tissues. In this article, we intend to first give a brief review on various known TAT approaches that are deemed promising for clinical applications in the current trend of personalized medicine, and then we will introduce our newly developed approach namely small molecular sequential dual targeting theragnostic strategy as a generalized class of TAT for the management of most solid malignancies, which, after optimization, is expected to help improve overall cancer treatability and curability.

Cranio-maxillofacial non-Hodgkin's lymphoma: clinical and histological presentation

Non-Hodgkin's lymphoma represents about 5% of all malignant lesions of the head and neck. In this study we retrospectively evaluated clinical presentation, histological subtype and long-term prognosis of 42 patients with non-Hodgkin's lymphoma involving the craniofacial area. The mean age at diagnosis was 64 years. More than half of the patients presented with disseminated disease at multiple sites (55%, n=23). In 62% (n=26) the first manifestation was extranodal. The most common affected region was the oral cavity (65%, n=17). Treatment consisted of local therapy, including surgical resection and radiation, as well as chemotherapy with or without local therapy. Recurrence occurred in 31% (n=13) of the treated patients. Mean survival after first diagnosis varied from 17 months in patients presenting with diffuse large B-cell lymphoma (DLBCL), to 8.5 years in patients with follicular lymphoma. The most common histological subtype is DLBCL. Standard treatment for DLBCL consists of chemotherapy combined with CD 20 monoclonal antibody, even after total resection of the tumour. There is high risk of systemic disease in patients presenting with non-Hodgkin's lymphoma and high risk of post therapy recurrence.

Dual phosphoproteomics and chemical proteomics analysis of erlotinib and gefitinib interference in acute myeloid leukemia cells

Small molecule inhibitors of protein kinases have emerged as a major class of therapeutic agents for the treatment of hematological malignancies. Both in vitro studies and patient case reports suggest therapeutic potential of the clinical kinase inhibitors erlotinib and gefitinib in acute myeloid leukemia (AML). The drugs' cellular modes of action in AML warrant further investigation as their primary therapeutic target, the epidermal growth factor receptor, is not expressed. We therefore performed SILAC-based quantitative mass spectrometry analyses to a depth of 10,975 distinct phosphorylation sites to characterize the phosphoproteome of KG1 AML cells and its regulation upon erlotinib and gefitinib treatment. Less than 50 site-specific phosphorylations changed significantly, indicating rather specific interference with AML cell signaling. Many drug-induced changes occurred within a network of tyrosine phosphorylated proteins that included Src family kinases (SFKs) and the tyrosine kinases Btk and Syk. We further performed quantitative chemical proteomics in KG1 cell extracts and identified SFKs and Btk as direct cellular targets of both erlotinib and gefitinib. Taken together, our data suggest that cellular perturbation of SFKs and/or Btk translates into rather specific signal transduction inhibition, which in turn contributes to the antileukemic activity of erlotinib and gefitinib in AML.

In search of CML stem cells' deadly weakness

Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder that is characterized by the presence of a fusion oncogene, BCR-ABL, which encodes a protein with constitutive tyrosine kinase activity. This activity causes excessive production of myeloid cells and their premature release into the circulation. The discovery of tyrosine kinase inhibitors marked a major advance in CML therapy, but these drugs cannot eradicate the disease because they are unable to kill the most primitive, quiescent leukemic stem cells. This review discusses current research in CML and attractive targets that have emerged with potential for eradicating the disease. Several new targets have recently been investigated as potential modulators in myeloid leukemia pathogenesis, including the multiple gene regulators miRNAs, the apparently leukemia-specific cell surface marker IL1RAP, transcription factors such as BMI1 and FOXOs, the tumor suppressors PML and PP2A, and the tyrosine kinase JAK2.

Autophagy induction by Bcr-Abl-expressing cells facilitates their recovery from a targeted or nontargeted treatment

Although Imatinib has transformed the treatment of chronic myeloid leukemia (CML), it is not curative due to the persistence of resistant cells that can regenerate the disease. We have examined how Bcr-Abl-expressing cells respond to two mechanistically different therapeutic agents, etoposide and Imatinib. We also examined Bcr-Abl expression at low and high levels as elevated expression has been associated with treatment failure. Cells expressing low levels of Bcr-Abl undergo apoptosis in response to the DNA-targeting agent (etoposide), whereas high-Bcr-Abl-expressing cells primarily induce autophagy. Autophagic populations engage a delayed nonapoptotic death; however, sufficient cells evade this and repopulate following the withdrawal of the drug. Non-Bcr-Abl-expressing 32D or Ba/F3 cells induce both apoptosis and autophagy in response to etoposide and can recover. Imatinib treatment induces both apoptosis and autophagy in all Bcr-Abl-expressing cells and populations rapidly recover. Inhibition of autophagy with ATG7 and Beclin1 siRNA significantly reduced the recovery of Imatinib-treated K562 cells, indicating the importance of autophagy for the recovery of treated cells. Combination regimes incorporating agents that disrupt Imatinib-induced autophagy would remain primarily targeted and may improve response to the treatment in CML.

Protein kinase networks regulating glucocorticoid-induced apoptosis of hematopoietic cancer cells: fundamental aspects and practical considerations

Glucocorticoids (GCs) are integral components in the treatment protocols of acute lymphoblastic leukemia, multiple myeloma, and non-Hodgkin lymphoma owing to their ability to induce apoptosis of these malignant cells. Resistance to GC therapy is associated with poor prognosis. Although they have been used in clinics for decades, the signal transduction pathways involved in GC-induced apoptosis have only partly been resolved. Accumulating evidence shows that this cell death process is mediated by a communication between nuclear GR affecting gene transcription of pro-apoptotic genes such as Bim, mitochondrial GR affecting the physiology of the mitochondria, and the protein kinase glycogen synthase kinase-3 (GSK3), which interacts with Bim following exposure to GCs. Prevention of Bim up-regulation, mitochondrial GR translocation, and/or GSK3 activation are common causes leading to GC therapy failure. Various protein kinases positively regulating the pro-survival Src-PI3K-Akt-mTOR and Raf-Ras-MEK-ERK signal cascades have been shown to be activated in malignant leukemic cells and antagonize GC-induced apoptosis by inhibiting GSK3 activation and Bim expression. Targeting these protein kinases has proven effective in sensitizing GR-positive malignant lymphoid cells to GC-induced apoptosis. Thus, intervening with the pro-survival kinase network in GC-resistant cells should be a good means of improving GC therapy of hematopoietic malignancies.

Immunopotentiating effect of proton pump inhibitor pantoprazole in a lymphoma-bearing murine host: Implication in antitumor activation of tumor-associated macrophages

Proton pump inhibitors (PPI) are being considered for antineoplastic therapeutic regimens due to their ability to reverse H(+) homeostasis in tumor microenvironment and induce tumor cell death. In order to explore additional mechanism(s) underlying antitumor action of PPI, the present investigation was undertaken to investigate the effect of a PPI pantoprazole (PPZ) on the activation of tumor-associated macrophages (TAM) to tumoricidal state in a murine model of a transplantable T cell lymphoma of spontaneous origin growing in ascitic form. In vivo administration of PPZ to tumor-bearing mice resulted in an enhanced TAM recruitment in tumor microenvironment with M1 macrophage phenotype and augmented activation of TAM to tumoricidal state along with expression of tumor cytotoxic molecules. The study also demonstrates that TAM activating action of PPZ is of indirect nature mediated via its antitumor activity, reversal of tumor-induced immunosuppression and a consequent shift of cytokine balance in the tumor microenvironment favoring polarization of macrophages to M1 type. The study further shows that adoptive transfer of TAM harvested from PPZ-administered tumor-bearing hosts causes an efficient retardation of tumor growth. Possible mechanisms and significance of these observations with respect to the designing of antitumor therapy using PPI are discussed.

B-lymphocyte homeostasis and BLyS-directed immunotherapy in transplantation

Current strategies for immunotherapy after transplantation are primarily T-lymphocyte directed and effectively abrogate acute rejection. However, the reality of chronic allograft rejection attests to the fact that transplantation tolerance remains an elusive goal. Donor-specific antibodies are considered the primary cause of chronic rejection. When naive, alloreactive B-cells encounter alloantigen and are activated, a resilient "sensitized" state, characterized by the presence of high-affinity antibody, is established. Here, we will delineate findings that support transient B-lymphocyte depletion therapy at the time of transplantation to preempt sensitization by eliminating alloreactive specificities from the recipient B-cell pool (ie, "repertoire remodeling"). Recent advances in our understanding of B-lymphocyte homeostasis provide novel targets for immunomodulation in transplantation. Specifically, the tumor necrosis factor-related cytokine BLyS is the dominant survival factor for "tolerance-susceptible" transitional and "preimmune" mature follicular B-cells. The transitional phenotype is the intermediate through which all newly formed B-cells pass before maturing into the follicular subset, which is responsible for mounting an alloantigen-specific antibody response. Systemic BLyS levels dictate the stringency of negative selection during peripheral B-cell repertoire development. Thus, targeting BLyS will likely provide an opportunity for repertoire-directed therapy to eliminate alloreactive B-cell specificities in transplant recipients, a requirement for the achievement of humoral tolerance and prevention of chronic rejection. In this review, the fundamentals of preimmune B-cell selection, homeostasis, and activation will be described. Furthermore, new and current B-lymphocyte-directed therapy for antibody-mediated rejection and the highly sensitized state will be discussed. Overall, our objective is to propose a rational approach for induction of humoral transplantation tolerance by remodeling the primary B-cell repertoire of the allograft recipient.