Identification of novel markers for monitoring minimal residual disease in acute lymphoblastic leukemia

Ninjurin1 deficiency differentially mitigates colorectal cancer induced by azoxymethane and dextran sulfate sodium in male and female mice

This study investigated the role of Ninjurin1 (Ninj1), encoding a small transmembrane protein, in colitis-associated colon tumorigenesis in relation to sex hormones. Male and female wild-type (WT) and Ninj1 knockout (KO) mice were treated with azoxymethane (AOM) and dextran sulfate sodium (DSS), with or without testosterone propionate (TP). At week 2 (acute colitis stage), Ninj1 KO exhibited an alleviation in the colitis symptoms in both male and female mice. The M2 macrophage population increased and CD8+ T cell population decreased only in the female Ninj1 KO than in the female WT AOM/DSS group. In the female AOM/DSS group, TP treatment exacerbated colon shortening in the Ninj1 KO than in the WT. At week 13 (tumorigenesis stage), male Ninj1 KO mice had fewer tumors, but females showed similar tumors. In the WT AOM/DSS group, females had more M2 macrophages and fewer M1 macrophages than males, but this difference was absent in Ninj1 KO mice. In the Ninj1 KO versus WT group, the expression of pro-inflammatory mediators and Ho-1 and CD8+ T cell populations decreased in both female and male Ninj1 KO mice. In the WT group, M2 macrophage populations were increased by AOM/DSS treatment and decreased by TP treatment. However, neither treatment changed the cell populations in the Ninj1 KO group. These results suggest that Ninj1 is involved in colorectal cancer development in a testosterone-dependent manner, which was different in male and female. This highlights the importance of considering sex disparities in understanding Ninj1's role in cancer pathogenesis.

CD58 expression does not impact response to inotuzumab ozogamicin in patients with B-cell acute lymphoblastic leukemia

Background

CD58 loss has been described as a mechanism of resistance to blinatumomab and chimeric antigen receptor T-cell therapy, functioning as a modulator of response to T-cell activation.

Methods

Using flow cytometry, we evaluated the impact of CD58 mean fluorescence intensity (MFI) on the probability of achieving measurable residual disease (MRD) negativity in patients with B-cell acute lymphoblastic leukemia treated with inotuzumab ozogamicin (InO).

Results

The odds ratio of achieving MRD negativity was 1.03 for every 1000 unit increase in CD58 MFI.

Conclusion

Our results suggest that MRD negativity rates after InO are high, regardless of the intensity of CD58 expression.

Multifaceted roles of ninjurin1 in immunity, cell death, and disease

Ninjurin1 (NINJ1) is initially identified as a nerve injury-induced adhesion molecule that facilitates axon growth. It is initially characterized to promote nerve regeneration and mediate the transendothelial transport of monocytes/macrophages associated with neuroinflammation. Recent evidence indicates that NINJ1 mediates plasma membrane rupture (PMR) in lytic cell death. The absence or inhibition of NINJ1 can delay PMR, thereby mitigating the spread of inflammation resulting from cell lysis and preventing the progression of various cell death-related pathologies, suggesting a conserved regulatory mechanism across these processes. Further research elucidated the structural basis and mechanism of NINJ1-mediated PMR. Although the role of NINJ1 in PMR is established, the identity of its activating factors and its implications in diseases remain to be fully explored. This review synthesizes current knowledge regarding the structural basis and mechanism of NINJ1-mediated PMR and discusses its significance and therapeutic targeting potential in inflammatory diseases, neurological disorders, cancer, and vascular injuries.

Construction and validation of a regulatory T cells-based classification of renal cell carcinoma: an integrated bioinformatic analysis and clinical cohort study

PURPOSE

Renal cell carcinoma (RCC), exhibiting remarkable heterogeneity, can be highly infiltrated by regulatory T cells (Tregs). However, the relationship between Treg and the heterogeneity of RCC remains to be explored.

METHODS

We acquired single-cell RNA-seq profiles and 537 bulk RNA-seq profiles of TCGA-KIRC cohort. Through clustering, monocle2 pseudotime and prognostic analyses, we identified Treg states-related prognostic genes (TSRPGs), then constructing the RCC Treg states-related prognostic classification (RCC-TSC). We also explored its prognostic significance and multi-omics landmarks. Additionally, we utilized correlation analysis to establish regulatory networks, and predicted candidate inhibitors. More importantly, in Xinhua cohort of 370 patients with kidney neoplasm, we used immunohistochemical (IHC) staining for classification, then employing statistical analyses including Chi-square tests and multivariate Cox proportional hazards regression analysis to explore its clinical relevance.

RESULTS

We defined 44 TSRPGs in four different monocle states, and identified high immune infiltration RCC (HIRC, LAG3+, Mki67+) as the highly exhausted subtype with the worst prognosis in RCC-TSC (p < 0.001). BATF-LAG3-immune cells axis might be its underlying metastasis-related mechanism. Immunotherapy and inhibitors including sunitinib potentially conferred best therapeutic effects for HIRC. Furthermore, we successfully validated HIRC subtype as an independent prognostic factor within the Xinhua cohort (OS, HR = 16.68, 95% CI = 1.88-148.1, p = 0.011; PFS, HR = 4.43, 95% CI = 1.55-12.6, p = 0.005).

CONCLUSION

Through integrated bioinformatics analysis and a large-sample retrospective clinical study, we successfully established RCC-TSC and a diagnostic kit, which could stratify RCC patients with different prognosis and to guide personalized treatment.

Immunophenotypic Characteristics and Cytogenetic Analysis of Adolescent and Young Adult B-Cell Acute Lymphoblastic Leukemia: Correlations With Clinicopathological Parameters

Introduction Acute lymphoblastic leukemia (ALL) has suboptimal survival rates for adolescents and young adults (AYA) as compared to children. Very limited studies have been conducted on AYA patients in India. This study aimed to identify the cytogenetic and immunophenotype characteristics of B-cell ALL (B-ALL) in AYA patients and determine its correlation with clinicopathological parameters in the Southern India region. Method The study was a prospective study conducted for three years, from June 2019 to May 2022, in India. Newly diagnosed 90 patients with AYA (13-40 years) ALL were recruited. A B-ALL diagnosis was made based on morphology with cytochemical stains and immunophenotype by flow cytometry (FCM). Cytogenetic analysis was also performed using karyotyping and fluorescent in situ hybridization to identify chromosomal aberrations. The cytogenetics results were correlated with immunophenotyping and clinicopathological characteristics. Variables were analyzed using the Mann-Whitney U test and Chi-square test using IBM SPSS Statistics for Windows, Version 20.0 (Released 2011; IBM Corp., Armonk, NY, USA). Results The mean age was 22.68 ± 8.06 years. It was observed that the most common structural chromosomal abnormality for AYA was t(9;22) in 14 (15%) cases, followed by 6q deletions in seven (8%) cases, t(1;19) in four (4%) cases, and t(12;17) and t(6;14) in two (2%) cases each. In addition, t(3;12), t(2;11), t(12;21), t(1;9), t(2;12), and t(X;10) were found in one (1%) case each. The most common numerical abnormality was hyperdiploidy (15; 17%), followed by hypodiploidy (10; 11%). Further, myeloid antigen expression of CD33 was the most common aberrantly expressed marker found in 20 (28%) cases, followed by CD15 in three cases (5%), CD13 in three (4%) cases, and CD11b in two (3%) cases. It was also observed that in Ph+ve cases, CD33 and CD13 were most commonly expressed in three (33%) and two (17%) cases, respectively. In contrast, in Ph-ve patients, their expressions were lesser at 17 (27%) and one (2%) cases, respectively. In addition, leukemia-associated immunophenotype pattern (LAIP) markers CD44 6 (86%) and CD123 5 (55%) were also found to be significantly associated with Ph+ve, whereas their values in the Ph-ve group were lesser at 25 (42%) and 9 (17%), respectively. Our data also showed that older age wassignificantly associated with Ph+ve with a median age of 30 years (p = 0.012). In comparison, the median age of Ph-ve was only 21 years. Conclusion Our study established that the incidence of cytogenetic abnormalities for AYA was consistent with previously reported data. This study reaffirms that Ph+ve cases have significant associations with MyAg (CD13), LAIP (CD123 and CD44), and older age for the South Indian population.

Remodelling of the glycome of B-cell precursor acute lymphoblastic leukemia cells developing drug-tolerance

Reduced responsiveness of precursor B-acute lymphoblastic leukemia (BCP-ALL) to chemotherapy can be first detected in the form of minimal residual disease leukemia cells that persist after 28 days of initial treatment. The ability of these cells to resist chemotherapy is partly due to the microenvironment of the bone marrow, which promotes leukemia cell growth and provides protection, particularly under these conditions of stress. It is unknown if and how the glycocalyx of such cells is remodelled during the development of tolerance to drug treatment, even though glycosylation is the most abundant cell surface post-translational modification present on the plasma membrane. To investigate this, we performed omics analysis of BCP-ALL cells that survived a 30-day vincristine chemotherapy treatment while in co-culture with bone marrow stromal cells. Proteomics showed decreased levels of some metabolic enzymes. Overall glycocalyx changes included a shift from Core-2 to less complex Core-1 O-glycans, and reduced overall sialylation, with a shift from α2-6 to α2-3 linked Neu5Ac. Interestingly, there was a clear increase in bisecting complex N-glycans with a concomitant increased mRNA expression of MGAT3 , the only enzyme known to form bisecting N-glycans. These small but reproducible quantitative differences suggest that individual glycoproteins become differentially glycosylated. Glycoproteomics confirmed glycosite-specific modulation of cell surface and lysosomal proteins in drug-tolerant BCP-ALL cells, including HLA-DRA, CD38, LAMP1 and PPT1. We conclude that drug-tolerant persister leukemia cells that grow under continuous chemotherapy stress have characteristic glycotraits that correlate with and perhaps contribute to their ability to survive and could be tested as neoantigens in drug-resistant leukemia.

Immunophenotypic portrait of leukemia-associated-phenotype markers in B acute lymphoblastic leukemia

BACKGROUND

Multiparametric flow cytometry (MFC) is an essential diagnostic tool in B acute lymphoblastic leukemia (B ALL) to determine the B-lineage affiliation of the blast population and to define their complete immunophenotypic profile. Most MFC strategies used in routine laboratories include leukemia-associated phenotype (LAP) markers, whose expression profiles can be difficult to interpret. The aim of our study was to reach a better understanding of 7 LAP markers' landscape in B ALL: CD9, CD21, CD66c, CD58, CD81, CD123, and NG2.

METHODS

Using a 10-color MFC approach, we evaluated the level of expression of 7 LAP markers including CD9, CD21, CD66c, CD58, CD81, CD123, and NG2, at the surface of normal peripheral blood leukocytes (n = 10 healthy donors), of normal precursor B regenerative cells (n = 40 uninvolved bone marrow samples) and of lymphoblasts (n = 100 peripheral blood samples or bone marrow samples from B ALL patients at diagnosis). The expression profile of B lymphoblasts was analyzed according the presence or absence of recurrent cytogenetic aberrations. The prognostic value of the 7 LAP markers was examined using Maxstat R algorithm.

RESULTS

In order to help the interpretation of the MFC data in routine laboratories, we first determined internal positive and negative populations among normal leukocytes for each of the seven evaluated LAP markers. Second, their profile of expression was evaluated in normal B cell differentiation in comparison with B lymphoblasts to establish a synopsis of their expression in normal hematogones. We then evaluated the frequency of expression of these LAP markers at the surface of B lymphoblasts at diagnosis of B ALL. CD9 was expressed in 60% of the cases, CD21 in only 3% of the cases, CD58 in 96% of the cases, CD66c in 45% of the cases, CD81 in 97% of the cases, CD123 in 72% of the cases, and NG2 in only 2% of the cases. We confirmed the interest of the CD81/CD58 MFI expression ratio as a way to discriminate hematogones from lymphoblasts. We observed a significant lower expression of CD9 and of CD81 at the surface of B lymphoblasts with a t(9;22)(BCR-ABL) in comparison with B lymphoblasts without any recurrent cytogenetic alteration (p = 0.0317 and p = 0.0011, respectively) and with B lymphoblasts harboring other cytogenetic recurrent abnormalities (p = 0.0032 and p < 0.0001, respectively). B lymphoblasts with t(1;19) at diagnosis significantly overexpressed CD81 when compared with B lymphoblasts with other recurrent cytogenetic abnormalities or without any recurrent alteration (p = 0.0001). An overexpression of CD58 was also observed in the cases harboring this abnormal cytogenetic event, when compared with B lymphoblasts with other recurrent cytogenetic abnormalities (p = 0.030), or without any recurrent alteration (p = 0.0002). In addition, a high expression of CD123, of CD58 and of CD81 was associated with a favorable prognosis in our cohort of pediatric and young adult B ALL patients. We finally built a risk score based on the expression of these 3 LAP markers, this scoring approach being able to split these patients into a high-risk group (17%) and a better outcome group (83%, p < 0.0001).

CONCLUSION

The complexity of the phenotypic signature of lymphoblasts at diagnosis of B ALL is illustrated by the variability in the expression of LAP antigens. Knowledge of the expression levels of these markers in normal leukocytes and during normal B differentiation is crucial for an optimal interpretation of diagnostic cytometry results and serves as a basis for the biological follow-up of B ALL.

Insights Regarding the Role of Inflammasomes in Leukemia: What Do We Know?

Inflammation is a physiological mechanism of the immune response and has an important role in maintaining the hematopoietic cell niche in the bone marrow. During this process, the participation of molecules produced by innate immunity cells in response to a variety of pathogen-associated molecular patterns and damage-associated molecular patterns is observed. However, chronic inflammation is intrinsically associated with leukemogenesis, as it induces DNA damage in hematopoietic stem cells and contributes to the creation of the preleukemic clone. Several factors influence the malignant transformation within the hematopoietic microenvironment, with inflammasomes having a crucial role in this process, in addition to acting in the regulation of hematopoiesis and its homeostasis. Inflammasomes are intracellular multimeric complexes responsible for the maturation and secretion of the proinflammatory cytokines interleukin-1β and interleukin-18 and the cell death process via pyroptosis. Therefore, dysregulation of the activation of these complexes may be a factor in triggering several diseases, including leukemias, and this has been the subject of several studies in the area. In this review, we summarized the current knowledge on the relationship between inflammation and leukemogenesis, in particular, the role of inflammasomes in different types of leukemias, and we describe the potential therapeutic targets directed at inflammasomes in the leukemic context.

SUMOylation of AnxA6 facilitates EGFR-PKCα complex formation to suppress epithelial cancer growth

BACKGROUND

The Annexin A6 (AnxA6) protein is known to inhibit the epidermal growth factor receptor (EGFR)-extracellular signal regulated kinase (ERK)1/2 signaling upon EGF stimulation. While the biochemical mechanism of AnxA6 inactivating phosphorylation of EGFR and ERK1/2 is not completely explored in cancer cells.

METHODS

Cells were transiently co-transfected with pFlag-AnxA6, pHA-UBC9 and pHis-SUMO1 plasmids to enrich the SUMOylated AnxA6 by immunoprecipitation, and the modification level of AnxA6 by SUMO1 was detected by Western blot against SUMO1 antibody. The SUMOylation level of AnxA6 was compared in response to chemical SUMOylation inhibitor treatment. AnxA6 SUMOylation sites were further identified by LC-MS/MS and amino acid site mutation validation. AnxA6 gene was silenced through AnxA6 targeting shRNA-containing pLKO.1 lentiviral transfection in HeLa cells, while AnxA6 gene was over-expressed within the Lenti-Vector carrying AnxA6 or mutant AnxA6^K299R plasmid in A431 cells using lentiviral infections. Moreover, the mutant plasmid pGFP-EGFR^T790M/L858R was constructed to test AnxA6 regulation on EGFR mutation-induced signal transduction. Moreover, cell proliferation, migration, and gefitinib chemotherapy sensitivity were evaluated in HeLa and A431 cells under AnxA6 konckdown or AnxA6 overexpression by CCK8, colony form and wound healing assays. And tumorigenicity in vivo was measured in epithelial cancer cells-xenografted nude mouse model.

RESULTS

AnxA6 was obviously modified by SUMO1 conjugation within Lys (K) residues, and the K299 was one key SUMOylation site of AnxA6 in epithelial cancer cells. Compared to the wild type AnxA6, AnxA6 knockdown and its SUMO site mutant AnxA6^K299R showed less suppression of dephosphorylation of EGFR-ERK1/2 under EGF stimulation. The SUMOylated AnxA6 was prone to bind EGFR in response to EGF inducement, which facilitated EGFR-PKCα complex formation to decrease the EGF-induced phosphorylation of EGFR-ERK1/2 and cyclin D1 expression. Similarly, AnxA6 SUMOylation inhibited dephosphorylation of the mutant EGFR, thereby impeding EGFR mutation-involved signal transduction. Moreover, AnxA6 knockdown or the K299 mutant AnxA6^K299R conferred AnxA6 inability to suppress tumor progression, resulting in drug resistance to gefitinib in epithelial cancer cells. And in epithelial cancer cells-xenografted nude mouse model, both the weight and size of tumors derived from AnxA6 knockdown or AnxA6^K299R mutation-expressing cells were much greater than that of AnxA6-expressing cells.

CONCLUSIONS

Besides EGFR gene mutation, protein SUMOylation modification of EGFR-binding protein AnxA6 also functions pivotal roles in mediating epithelial cancer cell growth and gefitinib drug effect. Video Abstract.

ANXA6: a key molecular player in cancer progression and drug resistance

Annexin-A6 (ANXA6), a Ca²⁺-dependent membrane binding protein, is the largest of all conserved annexin families and highly expressed in the plasma membrane and endosomal compartments. As a multifunctional scaffold protein, ANXA6 can interact with phospholipid membranes and various signaling proteins. These properties enable ANXA6 to participate in signal transduction, cholesterol homeostasis, intracellular/extracellular membrane transport, and repair of membrane domains, etc. Many studies have demonstrated that the expression of ANXA6 is consistently altered during tumor formation and progression. ANXA6 is currently known to mediate different patterns of tumor progression in different cancer types through multiple cancer-type specific mechanisms. ANXA6 is a potentially valuable marker in the diagnosis, progression, and treatment strategy of various cancers. This review mainly summarizes recent findings on the mechanism of tumor formation, development, and drug resistance of ANXA6. The contents reviewed herein may expand researchers' understanding of ANXA6 and contribute to developing ANXA6-based diagnostic and therapeutic strategies.

Antigen Receptors Gene Analysis for Minimal Residual Disease Detection in Acute Lymphoblastic Leukemia: The Role of High Throughput Sequencing

The prognosis of adult acute lymphoblastic leukemia (ALL) is variable but more often dismal. Indeed, its clinical management is challenging, current therapies inducing complete remission in 65–90% of cases, but only 30–40% of patients being cured. The major determinant of treatment failure is relapse; consequently, measurement of residual leukemic blast (minimal residual disease, MRD) has become a powerful independent prognostic indicator in adults. Numerous evidences have also supported the clinical relevance of MRD assessment for risk class assignment and treatment selection. MRD can be virtually evaluated in all ALL patients using different technologies, such as polymerase chain reaction amplification of fusion transcripts and clonal rearrangements of antigen receptor genes, flow cytometric study of leukemic immunophenotypes and, the most recent, high throughput sequencing (HTS). In this review, the authors focused on the latest developments on MRD monitoring with emphasis on the use of HTS, as well as on the clinical impact of MRD monitoring.

Immunophenotype of Measurable Residual Blast Cells as an Additional Prognostic Factor in Adults with B-Cell Acute Lymphoblastic Leukemia

Measurable residual disease (MRD) is a well-known independent prognostic factor in acute leukemias, and multicolor flow cytometry (MFC) is widely used to detect MRD. MFC is able not only to enumerate MRD accurately but also to describe an antigen expression profile of residual blast cells. However, the relationship between MRD immunophenotype and patient survival probability has not yet been studied. We determined the prognostic impact of MRD immunophenotype in adults with B-cell acute lymphoblastic leukemia (B-ALL). In a multicenter study RALL-2016 (NCT03462095), 267 patients were enrolled from 2016 to 2022. MRD was assessed at the end of induction (day 70) in 94 patients with B-ALL by six- or 10-color flow cytometry in the bone marrow specimens. The 4 year relapse-free survival (RFS) was lower in MRD-positive B-ALL patients [37% vs. 78% (p < 0.0001)]. The absence of CD10, positive expression of CD38, and high expression of CD58 on MRD cells worsened the 4 year RFS [19% vs. 51% (p = 0.004), 0% vs. 51% (p < 0.0001), and 21% vs. 40% (p = 0.02), respectively]. The MRD immunophenotype is associated with RFS and could be an additional prognostic factor for B-ALL patients.

DNAJC24 is a potential therapeutic target in hepatocellular carcinoma through affecting ammonia metabolism

Evolutionarily conserved heat shock proteins are involved in the heat shock response of cells in response to changes in the external environment. In normal tissues, heat shock proteins can help cells survive in a rapidly changing environment. Likewise, in malignant tumors heat shock proteins may help tumor cells cope with external stresses as well as the stress of treatment. In this way they become accomplices of malignant tumors. Here we demonstrated for the first time that high expression of DNAJC24 (a heat shock protein) shortens survival in patients with HCC by immunohistochemical staining of 167 paired hepatocellular carcinomas and paraneoplastic tissues as well as data from public databases. In vitro experiments demonstrated that stimuli such as hypoxia, starvation and heat could upregulate DNAJC24 expression in HCC cells through transcriptional regulation of HSF2, and high expression of DNAJC24 in HCC cells could promote the proliferation and motility of HCC cells. In addition, we also verified that targeting DNAJC24 under normal culture conditions can affect the proliferation and autophagy of HCC cells by interfering with ammonia metabolism, thereby inhibiting the malignant progression of HCC. Overall, we suggested that DNAJC24 may become a new target for the treatment of HCC.

Ninjurin1 drives lung tumor formation and progression by potentiating Wnt/β-Catenin signaling through Frizzled2-LRP6 assembly

BACKGROUND

Cancer stem-like cells (CSCs) play a pivotal role in lung tumor formation and progression. Nerve injury-induced protein 1 (Ninjurin1, Ninj1) has been implicated in lung cancer; however, the pathological role of Ninj1 in the context of lung tumorigenesis remains largely unknown.

METHODS

The role of Ninj1 in the survival of non-small cell lung cancer (NSCLC) CSCs within microenvironments exhibiting hazardous conditions was assessed by utilizing patient tissues and transgenic mouse models where Ninj1 repression and oncogenic Kras^G12D/+ or carcinogen-induced genetic changes were induced in putative pulmonary stem cells (SCs). Additionally, NSCLC cell lines and primary cultures of patient-derived tumors, particularly Ninj1^high and Ninj1^low subpopulations and those with gain- or loss-of-Ninj1 expression, and also publicly available data were all used to assess the role of Ninj1 in lung tumorigenesis.

RESULTS

Ninj1 expression is elevated in various human NSCLC cell lines and tumors, and elevated expression of this protein can serve as a biomarker for poor prognosis in patients with NSCLC. Elevated Ninj1 expression in pulmonary SCs with oncogenic changes promotes lung tumor growth in mice. Ninj1^high subpopulations within NSCLC cell lines, patient-derived tumors, and NSCLC cells with gain-of-Ninj1 expression exhibited CSC-associated phenotypes and significantly enhanced survival capacities in vitro and in vivo in the presence of various cell death inducers. Mechanistically, Ninj1 forms an assembly with lipoprotein receptor-related protein 6 (LRP6) through its extracellular N-terminal domain and recruits Frizzled2 (FZD2) and various downstream signaling mediators, ultimately resulting in transcriptional upregulation of target genes of the LRP6/β-catenin signaling pathway.

CONCLUSIONS

Ninj1 may act as a driver of lung tumor formation and progression by protecting NSCLC CSCs from hostile microenvironments through ligand-independent activation of LRP6/β-catenin signaling.

DNAJA1 promotes cancer metastasis through interaction with mutant p53

Accumulation of mutant p53 (mutp53) is crucial for its oncogenic gain of function activity. DNAJA1, a member of J-domain containing proteins or heat shock protein 40, is shown to prevent unfolded mutp53 from proteasomal degradation. However, the biological function of DNAJA1 remains largely unknown. Here we show that DNAJA1 promotes tumor metastasis by accumulating unfolded mutp53. Levels of DNAJA1 in head and neck squamous cell carcinoma (HNSCC) tissues were higher than those in normal tissues. Knockdown of DNAJA1 in HNSCC cell lines carrying unfolded mutp53 significantly decreased the levels of mutp53, filopodia/lamellipodia formation, migratory potential, and active forms of CDC42/RAC1, which were not observed in HNSCC cells with DNA contact mutp53, wild-type p53, or p53 null. Such mutp53-dependent functions of DNAJA1 were supported by the observation that DNAJA1 selectively bound to unfolded mutp53. Moreover, DNAJA1 knockdown in HNSCC cells carrying unfolded mutp53 inhibited primary tumor growth and metastases to the lymph nodes and lungs. Our study suggests that DNAJA1 promotes HNSCC metastasis mainly in a manner dependent on mutp53 status, suggesting DNAJA1 as a potential therapeutic target for HNSCC harboring unfolded mutp53.

CD58 Immunobiology at a Glance

The glycoprotein CD58, also known as lymphocyte-function antigen 3 (LFA-3), is a costimulatory receptor distributed on a broad range of human tissue cells. Its natural ligand CD2 is primarily expressed on the surface of T/NK cells. The CD2-CD58 interaction is an important component of the immunological synapse (IS) that induces activation and proliferation of T/NK cells and triggers a series of intracellular signaling in T/NK cells and target cells, respectively, in addition to promoting cell adhesion and recognition. Furthermore, a soluble form of CD58 (sCD58) is also present in cellular supernatant in vitro and in local tissues in vivo. The sCD58 is involved in T/NK cell-mediated immune responses as an immunosuppressive factor by affecting CD2-CD58 interaction. Altered accumulation of sCD58 may lead to immunosuppression of T/NK cells in the tumor microenvironment, allowing sCD58 as a novel immunotherapeutic target. Recently, the crucial roles of costimulatory molecule CD58 in immunomodulation seem to be reattracting the interests of investigators. In particular, the CD2-CD58 interaction is involved in the regulation of antiviral responses, inflammatory responses in autoimmune diseases, immune rejection of transplantation, and immune evasion of tumor cells. In this review, we provide a comprehensive summary of CD58 immunobiology.

Monitoring minimal/measurable residual disease in B-cell acute lymphoblastic leukemia by flow cytometry during targeted therapy

B-cell acute lymphoblastic leukemia (B-ALL) is a hematologic malignancy of B-type lymphoid precursor cells. Minimal/measurable residual disease (MRD) is an important prognostic factor for B-ALL relapse. Traditional flow cytometry detection mainly relies on CD19-based gating strategies. However, relapse of CD19-negative B-ALL frequently occurs in patients who receive cellular and targeted therapy. This review will summarize the technical aspects of standard MRD assessment in B-ALL by flow cytometry, and then discuss the challenges of MRD strategies to deal with the scenario of CD19 negative or dim B-ALL relapse.

Ninjurin 1 dodecamer peptide containing the N-terminal adhesion motif (N-NAM) exerts proangiogenic effects in HUVECs and in the postischemic brain

Nerve injury-induced protein 1 (Ninjurin 1, Ninj1) is a cell adhesion molecule responsible for cell-to-cell interactions between immune cells and endothelial cells. In our previous paper, we have shown that Ninj1 plays an important role in the infiltration of neutrophils in the postischemic brain and that the dodecamer peptide harboring the Ninj1 N-terminal adhesion motif (N-NAM, Pro²⁶-Asn³⁷) inhibits infiltration of neutrophils in the postischemic brain and confers robust neuroprotective and anti-inflammatory effects. In the present study, we examinedt the pro-angiogenic effect of N-NAM using human umbilical vein endothelial cells (HUVECs) and rat MCAO (middle cerebral artery occlusion) model of stroke. We found that N-NAM promotes proliferation, migration, and tube formation of HUVECs and demonstrate that the suppression of endogenous Ninj1 is responsible for the N-NAM-mediated pro-angiogenic effects. Importantly, a pull-down assay revealed a direct binding between exogenously delivered N-NAM and endogenous Ninj1 and it is N-terminal adhesion motif dependent. In addition, N-NAM activated the Ang1-Tie2 and AKT signaling pathways in HUVECs, and blocking those signaling pathways with specific inhibitors suppressed N-NAM-induced tube formation, indicating critical roles of those signaling pathways in N-NAM-induced angiogenesis. Moreover, in a rat MCAO model, intranasal administration of N-NAM beginning 4 days post-MCAO (1.5 µg daily for 3 days) augmented angiogenesis in the penumbra of the ipsilateral hemisphere of the brain and significantly enhanced total vessel lengths, vessel densities, and pro-angiogenic marker expression. These results demonstrate that the 12-amino acid Ninj1 peptide, which contains the N-terminal adhesion motif of Ninj1, confers pro-angiogenic effects and suggest that those effects might contribute to its neuroprotective effects in the postischemic brain.

Diverse Roles of Annexin A6 in Triple-Negative Breast Cancer Diagnosis, Prognosis and EGFR-Targeted Therapies

The calcium (Ca2+)-dependent membrane-binding Annexin A6 (AnxA6), is a multifunctional, predominantly intracellular scaffolding protein, now known to play relevant roles in different cancer types through diverse, often cell-type-specific mechanisms. AnxA6 is differentially expressed in various stages/subtypes of several cancers, and its expression in certain tumor cells is also induced by a variety of pharmacological drugs. Together with the secretion of AnxA6 as a component of extracellular vesicles, this suggests that AnxA6 mediates distinct tumor progression patterns via extracellular and/or intracellular activities. Although it lacks enzymatic activity, some of the AnxA6-mediated functions involving membrane, nucleotide and cholesterol binding as well as the scaffolding of specific proteins or multifactorial protein complexes, suggest its potential utility in the diagnosis, prognosis and therapeutic strategies for various cancers. In breast cancer, the low AnxA6 expression levels in the more aggressive basal-like triple-negative breast cancer (TNBC) subtype correlate with its tumor suppressor activity and the poor overall survival of basal-like TNBC patients. In this review, we highlight the potential tumor suppressor function of AnxA6 in TNBC progression and metastasis, the relevance of AnxA6 in the diagnosis and prognosis of several cancers and discuss the concept of therapy-induced expression of AnxA6 as a novel mechanism for acquired resistance of TNBC to tyrosine kinase inhibitors.

Improved Recognition of Hematogones From Precursor B-Lymphoblastic Leukemia by a Single Tube Flow Cytometric Analysis

OBJECTIVES

To improve diagnostic accuracy in differentiating hematogones from leukemic blasts in cases of precursor B-lymphoblastic leukemia/lymphoma (B-ALL), particularly those that are posttreatment or after bone marrow transplant, and to provide an algorithmic approach to this diagnostic challenge.

METHODS

A seven-color antibody panel including CD10, CD19, CD45, CD38, CD34, CD58, and CD81 was generated to assess the feasibility of a single tube panel and provide an algorithmic approach to distinguish hematogones from B-ALL. Fifty-three cases were analyzed, and results were correlated with histology and ancillary studies.

RESULTS

There was a significant difference in mean fluorescent intensity (MFI) for CD81 and CD58 when comparing hematogones and B-ALL populations (P < .001). B-ALL cases had a mean (SD) MFI of 24.6 (27.5; range, 2-125) for CD81 and 135.6 (72.6; range, 48-328) for CD58. Hematogones cases had a mean (SD) MFI of 70.2 (19.2; range, 42-123) for CD81 and 38.8 (9.4; range, 23-58) for CD58.

CONCLUSIONS

The flow cytometry panel with the above markers and utilization of the proposed algorithmic approach provide differentiation of hematogones from B-ALL. This includes rare cases of hematogones and B-ALL overlap where additional ancillary studies are necessary.

Reciprocal expression of Annexin A6 and RasGRF2 discriminates rapidly growing from invasive triple negative breast cancer subsets

Actively growing tumors are often histologically associated with Ki67 positivity, while the detection of invasiveness relies on non-quantitative pathologic evaluation of mostly advanced tumors. We recently reported that reduced expression of the Ca2+-dependent membrane-binding annexin A6 (AnxA6) is associated with increased expression of the Ca2+ activated RasGRF2 (GRF2), and that the expression status of these proteins inversely influence the growth and motility of triple negative breast cancer (TNBC) cells. Here, we establish that the reciprocal expression of AnxA6 and GRF2 is at least in part, dependent on inhibition of non-selective Ca2+ channels in AnxA6-low but not AnxA6-high TNBC cells. Immunohistochemical staining of breast cancer tissues revealed that compared to non-TNBC tumors, TNBC tumors express lower levels of AnxA6 and higher Ki67 expression. GRF2 expression levels strongly correlated with high Ki67 in pretreatment biopsies from patients with residual disease and with residual tumor size following chemotherapy. Elevated AnxA6 expression more reliably identified patients who responded to chemotherapy, while low AnxA6 levels were significantly associated with shorter distant relapse-free survival. Finally, the reciprocal expression of AnxA6 and GRF2 can delineate GRF2-low/AnxA6-high invasive from GRF2-high/AnxA6-low rapidly growing TNBCs. These data suggest that AnxA6 may be a reliable biomarker for distant relapse-free survival and response of TNBC patients to chemotherapy, and that the reciprocal expression of AnxA6 and GRF2 can reliably delineate TNBCs into rapidly growing and invasive subsets which may be more relevant for subset-specific therapeutic interventions.

Comparison between flow cytometry and standard PCR in the evaluation of MRD in children with acute lymphoblastic leukemia treated with the GBTLI LLA - 2009 protocol

Minimal residual disease (MRD) monitoring is of prognostic importance in childhood acute lymphoblastic leukemia (ALL). The detection of immunoglobulin and T-cell receptor gene rearrangements by real-time quantitative PCR (RT-PCR) is considered the gold standard for this evaluation. However, more accessible methods also show satisfactory performance. This study aimed to compare MRD analysis by four-color flow cytometry (FC) and qualitative standard PCR on days 35 and 78 of chemotherapy and to correlate these data with patients' clinical characteristics. Forty-two children with a recent diagnosis of ALL, admitted to a public hospital in Brazil for treatment in accordance with the Brazilian Childhood Cooperative Group for ALL Treatment (GBTLI LLA-2009), were included. Bone marrow samples collected at diagnosis and on days 35 and 78 of treatment were analyzed for the immunophenotypic characterization of blasts by FC and for the detection of clonal rearrangements by standard PCR. Paired analyses were performed in 61/68 (89.7%) follow-up samples, with a general agreement of 88.5%. Disagreements were resolved by RT-PCR, which evidenced one false-negative and four false-positive results in FC, as well as two false-negative results in PCR. Among the prognostic factors, a significant association was found only between T-cell lineage and MRD by standard PCR. These results show that FC and standard PCR produce similar results in MRD detection of childhood ALL and that both methodologies may be useful in the monitoring of disease treatment, especially in regions with limited financial resources.

Ninjurin1 Plays a Crucial Role in Pulmonary Fibrosis by Promoting Interaction between Macrophages and Alveolar Epithelial Cells

The transmembrane nerve injury-induced protein 1 (Ninjurin1 or Ninj1) is involved in progressing inflammatory diseases. In this study, we aimed to investigate a novel function of Ninj1 in pulmonary fibrosis. We found that the expression of Ninj1 in a patient cohort was upregulated in the lung specimens of idiopathic pulmonary fibrosis patients as well as mice with bleomycin-induced pulmonary fibrosis. In addition, the BLM-injected Ninj1 KO mice exhibited a mild fibrotic phenotype, as compared to WT mice. Therefore, we hypothesized that Ninj1 would play an important role in the development of pulmonary fibrosis. We discovered that Ninj1 expression increased in BLM-treated macrophages and alveolar epithelial cells (AECs). Interestingly, macrophages bound to BLM-treated AECs were activated. However, when Ninj1 expression was suppressed in either of AECs or macrophages, contact-dependent activation of macrophages with AECs was diminished. In addition, introduction of recombinant mouse Ninj1^1-50 to macrophages triggered an inflammatory response, but did not stimulate Ninj1-deficient macrophages. In conclusion, we propose that Ninj1 may contribute to activation of macrophages by enhancing interaction with AECs having elevated Ninj1 expression due to injury-inducing stimuli. Consequently, Ninj1 may be involved in the development of pulmonary fibrosis by enhancing inflammatory response of macrophages.

Expression of Nerve Injury-Induced Protein1 (Ninj1) in Endometriosis

OBJECTIVE

The aim of this study was to clarify the expression of Ninj1 in endometriosis and adenomyosis lesions, and its inductive factor in human endometriotic stromal cells (ESCs).

BACKGROUND

Nerve injury-induced protein 1 (Ninj1) is a molecule originally identified in dorsal root ganglion neurons and Schwann cells after nerve injury and promotes neurite outgrowth. The aim of this study was to clarify the expression of Ninj1 in endometriosis and adenomyosis lesions, and its inductive factor in human endometriotic stromal cells (ESCs).

MATERIALS AND METHODS

Tissues were obtained with consent from patients diagnosed with ovarian endometrioma (n = 15 in total), peritoneal endometriosis (n = 5), adenomyosis (n = 5), and other gynecological disorders (n = 5, control) during surgery. Immunohistochemistry was conducted in order to detect Ninj1 protein expression in the lesion of endometriosis, adenomyosis, and eutopic endometrium. Nerve fibers in the ovarian endometrioma were detected by positive staining of PGP-9.5. To evaluate the effects of IL-1β on Ninj1 gene expression in endometriosis, ESCs isolated from ovarian endometrioma (n = 5) were treated with IL-1β (5 ng/mL) for 3 or 6 hours. Messenger RNA (mRNA) expression for Ninj1 was examined using quantitative RT-PCR.

RESULTS

The Ninj1 protein was expressed by ovarian endometrioma, peritoneal endometriotic, and adenomyotic tissue. Nerve fibers were found in the areas of positive staining for Ninj1 in ovarian endometrioma. IL-1β, an indicator of inflammation in endometriosis, significantly increased Ninj1 mRNA expression by ESC.

CONCLUSION

Our study demonstrates that Ninj1 is expressed in endometriosis and adenomyosis and is induced by the inflammatory stimuli. Given the neurogenetic property of Ninj1, our results imply that Ninj1, induced by inflammation in endometriosis lesion, may contribute to the pathogenesis of pain symptoms characteristic of endometriosis.

Differential expression of CD73, CD86 and CD304 in normal vs. leukemic B-cell precursors and their utility as stable minimal residual disease markers in childhood B-cell precursor acute lymphoblastic leukemia

BACKGROUND

Optimal discrimination between leukemic blasts and normal B-cell precursors (BCP) is critical for treatment monitoring in BCP acute lymphoblastic leukemia (ALL); thus identification of markers differentially expressed on normal BCP and leukemic blasts is required.

METHODS

Multicenter analysis of CD73, CD86 and CD304 expression levels was performed in 282 pediatric BCP-ALL patients vs. normal bone marrow BCP, using normalized median fluorescence intensity (nMFI) values.

RESULTS

CD73 was expressed at abnormally higher levels (vs. pooled normal BCP) at diagnosis in 71/108 BCP-ALL patients (66%), whereas CD304 and CD86 in 119/202 (59%) and 58/100 (58%) patients, respectively. Expression of CD304 was detected at similar percentages in common-ALL and pre-B-ALL, while found at significantly lower frequencies in pro-B-ALL. A significant association (p = 0.009) was found between CD304 expression and the presence of the ETV6-RUNX1 fusion gene. In contrast, CD304 showed an inverse association with MLL gene rearrangements (p = 0.01). The expression levels of CD73, CD86 and CD304 at day 15 after starting therapy (MRD15) were stable or higher than at diagnosis in 35/37 (95%), 40/56 (71%) and 19/41 (46%) cases investigated, respectively. This was also associated with an increased mean nMFI at MRD15 vs. diagnosis of +24 and +3 nMFI units for CD73 and CD86, respectively. In addition, gain of expression of CD73 and CD86 at MRD15 for cases that were originally negative for these markers at diagnosis was observed in 16% and 18% of cases, respectively. Of note, CD304 remained aberrantly positive in 63% of patients, despite its levels of expression decreased at follow-up in 54% of cases.

CONCLUSIONS

Here we show that CD73, CD86 and CD304 are aberrantly (over)expressed in a substantial percentage of BCP-ALL patients and that their expression profile remains relatively stable early after starting therapy, supporting their potential contribution to improved MRD analysis by flow cytometry.

Functional blocking of Ninjurin1 as a strategy for protecting endothelial cells in diabetes mellitus

Ongoing efforts to remove pathological inflammatory stimuli are crucial for the protection of endothelial cells in diabetes. Nerve injury-induced protein 1 (Ninj1) is an adhesion molecule that not only contributes to inflammation but also regulates the apoptosis of endothelial cells. In the present study, Ninj1 was found highly expressed in endothelial cells in Type 2 diabetic mice and increased in high-glucose (HG) cultured HUVECs. Furthermore, we found that Ninj1 levels are up-regulated in endothelial cells in clinical specimens of diabetic patients when compared with nondiabetic tissues, indicating a biological correlation between Ninj1 and endothelial pathophysiology in diabetic condition. Functional blocking of Ninj1 promoted endothelial tube formation and eNOS phosphorylation in the HG condition. Additionally, blocking Ninj1 inhibited the activation of caspase-3 and increased the Bcl-2/Bax ratio, thus inhibiting HUVECs apoptosis induced by HG. HG-induced ROS overproduction, p38 MAPK and NF-κB activation, and the overexpression of VCAM-1, ICAM-1, MCP-1, and IL-6 genes were ameliorated after Ninj1 was blocked. Using the signaling pathway inhibitor LY294002, we found that Bcl-2 expression and eNOS phosphorylation after Ninj1 blockade were regulated via PI3K/Akt signaling pathway. The in vivo endothelial contents, α-SMA⁺PECAM-1⁺ vascular numbers, and blood perfusion in the hindlimb were markedly up-regulated after Ninj1 was blocked. According to our findings, functional blocking of Ninj1 shows protective effects on diabetic endothelial cells both in vitro and in vivo Thus, we consider Ninj1 to be a potential therapeutic target for preventing endothelial dysfunction in diabetes mellitus.

Ninjurin1 inhibits colitis-mediated colon cancer development and growth by suppression of macrophage infiltration through repression of FAK signaling

Macrophage infiltration promotes tumorigenesis. However, the macrophage infiltration regulatory molecules have not been fully determined. Nerve injury-induced protein 1 (ninjurin1) is a homophilic cell surface adhesion molecule that plays an important role in cell migration and attachment. Although ninjurin1 is believed to play a role in several malignancies, it is unclear whether ninjurin1 expression contributes to cancer progression. We used transgenic mice (tg mice) that overexpressed ninjurin1 on macrophages. We subjected ninjurin1 tg mice to a well-known mouse model of colitis-associated colon cancer in which animals are treated with azoxymethane (AOM) and dextran sulfate sodium (DSS). After AOM and DSS treatment, ninjurin1 tg mice developed fewer and smaller tumors compared with wild-type (wt) mice. Ninjurin1 tg mice also showed reduced infiltration of macrophages and suppressed angiogenesis in the tumor mass. We therefore explored whether ninjurin1 decreases macrophage migration into the tumor sites. After adoptive transfer to tumor-bearing recipients, wild type and ninjurin1 tg mice's peritoneal macrophages were freshly isolated and labeled with carboxyfluorescein succinimidyl ester (CFSE). As expected, compared with that of wt type macrophages, tumor infiltration of ninjurin1-overexpressing macrophages was significantly decreased. We also found that ninjurin1 overexpression suppressed FAK activity. In addition, knockdown of ninjurin1 enhanced FAK activity and migration activity of RAW264.7 cells. Ninjurin1 overexpression on macrophage inhibits tumor growth by suppression of macrophage infiltration through repression of FAK signaling. Ninjurin1 is a key regulator molecule for macrophage migration and Tumor-associated macrophages (TAM) mediated tumorigenesis in vivo.

Targeting Heat Shock Proteins in Cancer: A Promising Therapeutic Approach

Heat shock proteins (HSPs) are a large family of chaperones that are involved in protein folding and maturation of a variety of "client" proteins protecting them from degradation, oxidative stress, hypoxia, and thermal stress. Hence, they are significant regulators of cellular proliferation, differentiation and strongly implicated in the molecular orchestration of cancer development and progression as many of their clients are well established oncoproteins in multiple tumor types. Interestingly, tumor cells are more HSP chaperonage-dependent than normal cells for proliferation and survival because the oncoproteins in cancer cells are often misfolded and require augmented chaperonage activity for correction. This led to the development of several inhibitors of HSP90 and other HSPs that have shown promise both preclinically and clinically in the treatment of cancer. In this article, we comprehensively review the roles of some of the important HSPs in cancer, and how targeting them could be efficacious, especially when traditional cancer therapies fail.

Potential therapeutic targets and small molecular drugs for pediatric B-precursor acute lymphoblastic leukemia treatment based on microarray data

The current study investigated the molecular mechanisms underlying pediatric acute lymphoblastic leukemia (ALL) and screened for small molecular drugs as supplementary drugs to aid current therapy. Gene expression data of Gene Expression Omnibus (GEO) DataSet GSE42221, which consists of 7 primary human B-precursor samples and 4 control B-cell progenitor lymphoblast samples from patients with pediatric ALL, were downloaded from the public GEO database. Linear Models for Microarray Analysis package for R statistical software was used to identify differentially expressed genes (DEGs). Subsequently, biclustering analysis of DEGs was performed using pheatmap package for R. Functional enrichment analysis of DEGs was conducted using the Database for Annotation, Visualization and Integrated Discovery tool. Additionally, Search Tool for the Retrieval of Interacting Genes software was used to screen protein-protein interactions (PPIs) of the DEGs, and Connectivity Map database was employed to obtain small-molecule drugs that were significantly associated with DEGs. In total, 116 genes were identified as DEGs in pediatric ALL, including 56 downregulated and 60 upregulated genes. Functional enrichment analysis identified that upregulated DEGs, including marker of proliferation Ki-67, cyclin F and nucleolar and spindle associated protein 1, were significantly enriched in mesenchymal cell differentiation and development processes, whilst downregulated DEGs, including bone marrow morphogenetic protein 2, semaphoring 3F and ephrin B1 were enriched in cell cycle process. Amongst the DEGs, 169 PPIs were identified. Notably, carbimazole and quinostatin were associated with DEGs. Additionally, a number of DEGs were targeted by the two drugs, including signal transducer and activator of transcription 3, nucleolar and spindle associated protein 1 and cell division cycle 20. Mesenchymal cell differentiation and development as well as cell cycle processes may be important for pediatric ALL. Quinostatin may be used as a potent supplementary drug for treating pediatric ALL.

Heat Shock Proteins and Cancer

Heat shock proteins (HSPs) constitute a large family of proteins involved in protein folding and maturation whose expression is induced by heat shock or other stressors. The major groups are classified based on their molecular weights and include HSP27, HSP40, HSP60, HSP70, HSP90, and large HSPs. HSPs play a significant role in cellular proliferation, differentiation, and carcinogenesis. In this article we comprehensively review the roles of major HSPs in cancer biology and pharmacology. HSPs are thought to play significant roles in the molecular mechanisms leading to cancer development and metastasis. HSPs may also have potential clinical uses as biomarkers for cancer diagnosis, for assessing disease progression, or as therapeutic targets for cancer therapy.

Evaluation of new markers for minimal residual disease monitoring in B-cell precursor acute lymphoblastic leukemia: CD73 and CD86 are the most relevant new markers to increase the efficacy of MRD 2016; 00B: 000-000

BACKGROUND

Multiparametric flow cytometry (MFC) is a popular technique for minimal residual disease (MRD) analysis. However, its applicability is still limited to 90% of B-cell precursor acute lymphoblastic leukemia (BCPALL) due to two major issues, i.e. a proportion of cases do not express adequate leukemia associated immunophenotype (LAIPs) with currently used markers and drug-induced antigen modulation. Hence, the incorporation of additional reliable markers is required for the further improvement of MFC-based MRD evaluation. We studied the utility of new markers in improvising MFC-based MRD detection in BCPALL.

METHODS

Expression-patterns of six new markers, i.e. CD24, CD44, CD72, CD73, CD86, and CD200 were studied in leukemic-blasts from ninety childhood BCPALL patients and in hematogones from 20 uninvolved staging bone marrow (BM) and ten postinduction non-BCPALL BM samples using eight-color MFC. The utility of these new markers in the day 35 postinduction MRD evaluation was determined.

RESULTS

Frequencies of LAIPs of CD73, CD86, CD72, CD44, CD200, and CD24 in diagnostic samples were 76.7, 56.7, 55.6, 50, 28.9, and 20%, respectively. Differential expression of all new markers was highly significant (P < 0.01) between early (CD10+ CD19+ CD34+) hematogones, late (CD10+ CD19+ CD34-) hematogones and BCPALL blasts except between early hematogones and BCPALL blasts for CD200 (P = 0.1). In MRD-positive samples, CD73 showed the maximum (83%) frequency of LAIP and CD86 showed the highest (100%) stability of aberrant expression. Inclusion of CD73 and CD86 increased the applicability of MFC-MRD assay to 98.9% MRD samples.

CONCLUSION

CD73 and CD86 are the most relevant markers to incorporate in the routine MRD evaluation of BCPALL. © 2016 International Clinical Cytometry Society.

Impact of pretransplant minimal residual disease on the post-transplant outcome of pediatric acute lymphoblastic leukemia

There are few reports on the clinical significance of MRD before HSCT in pediatric ALL. We retrospectively analyzed the clinical significance of FCM-based detection of MRD (FCM-MRD) before allogeneic HSCT in pediatric ALL. Of 38 pediatric patients who underwent allogeneic HSCT for the first time between 1998 and 2014, 33 patients were in CR and five patients were in non-CR. The CR group was further divided into two groups based on the pretransplant FCM-MRD level: the MRD(neg) (<0.01%; 30 patients) group and the MRD(pos) (≥0.01%; three patients) group. There were significant differences in the three-yr event-free survival rates between the CR and non-CR group, and between the MRD(neg) and MRD(pos) group. The three-yr cumulative RI in the MRD(neg) group were 27.3% ± 8.8%, whereas two of the three patients in the MRD(pos) group relapsed within one yr after HSCT. The clinical outcome of the MRD(pos) group was as poor as that of the non-CR group in pediatric ALL. Therefore, an improvement in pretransplant treatment that aims to achieve a more profound remission would contribute to reducing the risk of relapse.

Key Markers of Minimal Residual Disease in Childhood Acute Lymphoblastic Leukemia

The aim of this study was to identify key markers of minimal residual disease (MRD) in childhood Acute Lymphoblastic Leukemia (ALL). Bone marrow samples were collected at presentation from 139 patients with newly diagnosed B-lineage ALL. On the basis of the expression of CD19, CD10, and CD34 antigens by bone marrow cells, combined with the terminal deoxynucleotide transferase (TdT), CD38, CD45, CD58, CD21, CD66c, CD22, and CD33 expression patterns characterized at diagnosis, leukemia-associated immunophenotypes (LAIPs) were identified. One hundred thirty-nine patients with a median age of 4.3 years were screened with 4-color flow cytometry MRD screening, and 119 of them exhibited 1 or more LAIP suitable for further monitoring, constituting a coverage rate of 85.6%. Only 20 of the 139 (14.4%) had no LAIP identified for follow-up. The most applicable antibody combination was TdT/CD10/CD34/CD19 (87/139, 62.6%), followed by CD38/CD10/CD34/CD19 (85/139, 61.2%) and CD45/CD10/CD34/CD19 (58/139, 41.7%). We have identified a relatively effective MRD panel, combined with TdT, CD38, and CD45 as key markers, that is applicable to the majority of newly diagnosed B-lineage ALL.

Current Strategies for the Detection of Minimal Residual Disease in Childhood Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) is the most common cancer in children. Current treatment strategies for childhood ALL result in long-term remission for approximately 90% of patients. However, the therapeutic response is worse among those who relapse. Several risk stratification approaches based on clinical and biological aspects have been proposed to intensify treatment in patients with high risk of relapse and reduce toxicity on those with a greater probability of cure.

The detection of residual leukemic cells (minimal residual disease, MRD) is the most important prognostic factor to identify high-risk patients, allowing redefinition of chemotherapy. In the last decades, several standardized research protocols evaluated MRD using immunophenotyping by flow cytometry and/or real-time quantitative polymerase chain reaction at different time points during treatment. Both methods are highly sensitive (10⁻³ a 10⁻⁵), but expensive, complex, and, because of that, require qualified staff and frequently are restricted to reference centers.

The aim of this article was to review technical aspects of immunophenotyping by flow cytometry and real-time quantitative polymerase chain reaction to evaluate MRD in ALL.

AP-1 Is a Key Regulator of Proinflammatory Cytokine TNFα-mediated Triple-negative Breast Cancer Progression

Triple-negative breast cancer (TNBC) represents a highly aggressive form of breast cancer with limited treatment options. Proinflammatory cytokines such as TNFα can facilitate tumor progression and metastasis. However, the mechanistic aspects of inflammation mediated TNBC progression remain unclear. Using ChIP-seq, we demonstrate that the cistrome for the AP-1 transcription factor c-Jun is comprised of 13,800 binding regions in TNFα-stimulated TNBC cells. In addition, we show that c-Jun regulates nearly a third of the TNFα-regulated transcriptome. Interestingly, high expression level of the c-Jun-regulated pro-invasion gene program is associated with poor clinical outcome in TNBCs. We further demonstrate that c-Jun drives TNFα-mediated increase of malignant characteristics of TNBC cells by transcriptional regulation of Ninj1. As exemplified by the CXC chemokine genes clustered on chromosome 4, we demonstrate that NF-κB might be a pioneer factor required for the regulation of TNFα-inducible inflammatory genes, whereas c-Jun has little effect. Together, our results uncover AP-1 as an important determinant for inflammation-induced cancer progression, rather than inflammatory response.

Role of annexin A6 in cancer

Annexin A6 (AnxA6) is a member of a conserved superfamily of Ca²⁺-dependent membrane-binding annexin proteins. It participates in membrane and cytoskeleton organization, cholesterol homeostasis, membrane trafficking, cell adhesion and signal transduction. The expression levels of AnxA6 are closely associated with melanoma, cervical cancer, epithelial carcinoma, breast cancer, gastric cancer, prostate cancer, acute lymphoblastic leukemia, chronic myeloid leukemia, large-cell lymphoma and myeloma. AnxA6 exhibits dual functions in cancer, acting either as a tumor suppressor or promoter, depending on the type of cancer and the degree of malignancy. In several types of cancer, AnxA6 acts via Ras, Ras/MAPK and/or FAK/PI3K signaling pathways by mainly mediating PKCα, p120GAP, Bcr-Abl and YY1. In the present review, the roles of AnxA6 in different types of cancer are summarized.

Minimal residual disease testing in acute leukemia

SUMMARY Predictive/prognostic factors in acute leukemia continue to be sought, in order to refine treatment strategies. Minimal residual disease (MRD) testing has been shown to be a statistically significant factor by multivariate analysis in both acute lymphoblastic leukemia (ALL) and acute myeloid leukemia. Its utility in guiding therapy has been more extensively studied in pediatric ALL, with some protocols having instituted MRD testing into therapeutic algorithms. The clinical impact of MRD testing in ALL and acute myeloid leukemia will be presented, including both molecular and flow cytometric methodologies, with a more focused discussion of the strategy, methodology and interpretation of MRD testing by multiparametric flow cytometry.

1H, 13C and 15N chemical shift assignments of Ninjurin1 Extracellular N-terminal Domain

Cell adhesion molecules play a crucial role in fundamental biological processes via regulating cell-cell interactions. Nerve injury induced protein1 (Ninjurin1) is a novel adhesion protein that has no significant homology with other known cell adhesion molecules. Here we present the assignment of an 81 aa construct for human Ninjurin1 Extracellular N-Terminal (ENT) domain, which comprises the critical adhesion domain.

Ninjurin1, a target of p53, regulates p53 expression and p53-dependent cell survival, senescence, and radiation-induced mortality

The tumor suppressor protein p53 plays a crucial role in coordinating cellular processes, such as cell cycle arrest, apoptosis, and senescence. The nerve injury-induced protein 1 (Ninjurin1, Ninj1) is a homophilic adhesion molecule and involved in nerve regeneration. Interestingly, Ninj1 is found to be overexpressed in human cancer, but its role in tumorigenesis is not clear. Here, we found that Ninj1 is transcriptionally regulated by p53 and can be induced by DNA damage in a p53-dependent manner. We also found that knockout or knockdown of Ninj1 increases p53 expression potentially through enhanced p53 mRNA translation. In addition, we found that Ninj1 deficiency suppresses cell proliferation but enhances apoptosis and premature senescence in a p53-dependent manner. Consistent with this, we found that mice heterozygous in ninj1 are hypersensitive to ionizing radiation-induced lethality, along with increased expression of p53 in thymus. Taken together, we provided evidence that Ninj1 is a p53 target and modulates p53 mRNA translation and p53-dependent premature senescence, cell proliferation, apoptosis, and radiation-induced mortality in vitro and in vivo. Thus, we postulate that as a membrane adhesion molecule, Ninj1 is an ideal target to regulate p53 activity via the p53-Ninj1 loop.

Leukemia surfaceome analysis reveals new disease-associated features

A better description of the leukemia cell surface proteome (surfaceome) is a prerequisite for the development of diagnostic and therapeutic tools. Insights into the complexity of the surfaceome have been limited by the lack of suitable methodologies. We combined a leukemia xenograft model with the discovery-driven chemoproteomic Cell Surface Capture technology to explore the B-cell precursor acute lymphoblastic leukemia (BCP-ALL) surfaceome; 713 cell surface proteins, including 181 CD proteins, were detected through combined analysis of 19 BCP-ALL cases. Diagnostic immunophenotypes were recapitulated in each case, and subtype specific markers were detected. To identify new leukemia-associated markers, we filtered the surfaceome data set against gene expression information from sorted, normal hematopoietic cells. Nine candidate markers (CD18, CD63, CD31, CD97, CD102, CD157, CD217, CD305, and CD317) were validated by flow cytometry in patient samples at diagnosis and during chemotherapy. CD97, CD157, CD63, and CD305 accounted for the most informative differences between normal and malignant cells. The ALL surfaceome constitutes a valuable resource to assist the functional exploration of surface markers in normal and malignant lymphopoiesis. This unbiased approach will also contribute to the development of strategies that rely on complex information for multidimensional flow cytometry data analysis to improve its diagnostic applications.

Fat1 cadherin provides a novel minimal residual disease marker in acute lymphoblastic leukemia

Measurement of minimal residual disease (MRD) maintains an important role in the clinical management of acute lymphoblastic leukemia (ALL). Recently, we identified Fat1 cadherin as a unique and independent prognostic factor for relapse-free and overall survival in pediatric pre-B-ALL. Here, we analyzed Fat1 mRNA for its potential as a novel marker of MRD in cases of pre-B- and T-ALL. Analyses of microarray data from 125 matched diagnosis/relapse samples across three independent datasets indicate that Fat1 mRNA is detectable in an average of 31.3% of diagnosed pre-B-ALL, of which 67.5% of cases remained positive at relapse. Furthermore, some 20% of cases with undetectable levels of Fat1 mRNA at diagnosis became positive upon relapse. T-ALL cases were 83.3% positive for Fat1 expression at diagnosis with 77.7% remaining positive at relapse. Towards proof of concept, we developed a quantitative polymerase chain reaction assay and demonstrate detection of Fat1 mRNA in leukemic cells mixed with normal peripheral blood cells at a sensitivity of 1 in 10 000 to 100 000 cells. Fat1 may therefore provide a new marker of MRD for patients with ALL lacking known genomic aberrations or within a multiplex approach to MRD detection.

EuroFlow antibody panels for standardized n-dimensional flow cytometric immunophenotyping of normal, reactive and malignant leukocytes

Most consensus leukemia & lymphoma antibody panels consist of lists of markers based on expert opinions, but they have not been validated. Here we present the validated EuroFlow 8-color antibody panels for immunophenotyping of hematological malignancies. The single-tube screening panels and multi-tube classification panels fit into the EuroFlow diagnostic algorithm with entries defined by clinical and laboratory parameters. The panels were constructed in 2-7 sequential design-evaluation-redesign rounds, using novel Infinicyt software tools for multivariate data analysis. Two groups of markers are combined in each 8-color tube: (i) backbone markers to identify distinct cell populations in a sample, and (ii) markers for characterization of specific cell populations. In multi-tube panels, the backbone markers were optimally placed at the same fluorochrome position in every tube, to provide identical multidimensional localization of the target cell population(s). The characterization markers were positioned according to the diagnostic utility of the combined markers. Each proposed antibody combination was tested against reference databases of normal and malignant cells from healthy subjects and WHO-based disease entities, respectively. The EuroFlow studies resulted in validated and flexible 8-color antibody panels for multidimensional identification and characterization of normal and aberrant cells, optimally suited for immunophenotypic screening and classification of hematological malignancies.