Interleukin-6 in multiple myeloma: correlation with disease activity and Ki-67 proliferation index

Mesenchymal stromal cell senescence in haematological malignancies

Acute myeloid leukaemia (AML), chronic lymphocytic leukaemia (CLL), and multiple myeloma (MM) are age-related haematological malignancies with defined precursor states termed myelodysplastic syndrome (MDS), monoclonal B-cell lymphocytosis (MBL), and monoclonal gammopathy of undetermined significance (MGUS), respectively. While the progression from asymptomatic precursor states to malignancy is widely considered to be mediated by the accumulation of genetic mutations in neoplastic haematopoietic cell clones, recent studies suggest that intrinsic genetic changes, alone, may be insufficient to drive the progression to overt malignancy. Notably, studies suggest that extrinsic, microenvironmental changes in the bone marrow (BM) may also promote the transition from these precursor states to active disease. There is now enhanced focus on extrinsic, age-related changes in the BM microenvironment that accompany the development of AML, CLL, and MM. One of the most prominent changes associated with ageing is the accumulation of senescent mesenchymal stromal cells within tissues and organs. In comparison with proliferating cells, senescent cells display an altered profile of secreted factors (secretome), termed the senescence-associated-secretory phenotype (SASP), comprising proteases, inflammatory cytokines, and growth factors that may render the local microenvironment favourable for cancer growth. It is well established that BM mesenchymal stromal cells (BM-MSCs) are key regulators of haematopoietic stem cell maintenance and fate determination. Moreover, there is emerging evidence that BM-MSC senescence may contribute to age-related haematopoietic decline and cancer development. This review explores the association between BM-MSC senescence and the development of haematological malignancies, and the functional role of senescent BM-MSCs in the development of these cancers.

Advantages and drawbacks of dexamethasone in glioblastoma multiforme

The most widespread, malignant, and deadliest type of glial tumor is glioblastoma multiforme (GBM). Despite radiation, chemotherapy, and radical surgery, the median survival of afflicted individuals is about 12 months. Unfortunately, existing therapeutic interventions are abysmal. Dexamethasone (Dex), a synthetic glucocorticoid, has been used for many years to treat brain edema and inflammation caused by GBM. Several investigations have recently shown that Dex also exerts antitumoral effects against GBM. On the other hand, more recent disputed findings have questioned the long-held dogma of Dex treatment for GBM. Unfortunately, steroids are associated with various undesirable side effects, including severe immunosuppression and metabolic changes like hyperglycemia, which may impair the survival of GBM patients. Current ideas and concerns about Dex's effects on GBM cerebral edema, cell proliferation, migration, and its clinical outcomes were investigated in this study.

Meclofenamic acid represses spermatogonial proliferation through modulating m6A RNA modification

Background

N6-Methyladenosine (m⁶A), the most prevalent modification in mammalian mRNA, plays important roles in numerous biological processes. Several m⁶A associated proteins such as methyltransferase like 3 (METTL3), methyltransferase like 14 (METTL14), α-ketoglutarate-dependent dioxygenase AlkB homolog 5 (ALKBH5) and YTH domain containing 2 (YTHDC2) are involved in the regulation of spermatogenesis and oogenesis. However, the role of the first detected m6A demethylase, fat mass and obesity associate protein (FTO), in germ cells remains elusive. Elucidation of FTO roles in the regulation of germ cell fate will provide novel insights into the mammalian reproduction.

Methods

Mouse GC-1 spg cells were treated with the ester form of meclofenamic acid (MA2) to inhibit the demethylase activity of FTO. The cellular m⁶A and m⁶A_m level were analyzed through high performance liquid chromatography combined with tandem mass spectrometry (HPLC/MS-MS). The cell apoptosis was detected via TUNEL and flow cytometry. The cell proliferation was detected through EdU and western blot. The mRNA level of core cyclin dependent kinases (CDKs) was quantified via q-PCR. RNA decay assay were performed to detect RNA stability. Dual fluorescence assay was conducted to study whether MA2 affects the expression of CDK2 dependent on the m⁶A modification at 3’UTR.

Results

MA2 significantly increased the cellular m⁶A level and down-regulated the expression of CDK1, CDK2, CDK6 and CdC25a, resulting in arrest of G1/S transition and decrease of cell proliferation. MA2 downregulated CDK2 mRNA stability. Additionally, mutation of the predicted m⁶A sites in the Cdk2–3’UTR could mitigated the degradation of CDK2 mRNA after MA2 treatment.

Conclusion

MA2 affected CDKs expression through the m⁶A-dependent mRNA degradation pathway, and thus repressed spermatogonial proliferation.

Electronic supplementary material

The online version of this article (10.1186/s40104-019-0361-6) contains supplementary material, which is available to authorized users.

Proliferation and Angiogenesis Using Immunohistochemistry in Prognosticating Multiple Myeloma

Multiple myeloma is a neoplasm of plasma cells characterised by the presence of M protein in serum and urine. Angiogenesis and proliferation play a major role in the pathogenesis of various neoplasms. The study evaluated proliferation and angiogenesis in 48 cases of myeloma, and correlated it with morphological and clinical parameters. The histomorphological features like plasma cell morphology, percentage of plasma cells and pattern of infiltration were studied in the bone marrow aspirate and trephine biopsy. Angiogenesis was assessed by calculating the microvessel density (MVD) using immunohistochemistry for CD34. Proliferation was assessed using Ki67 and CD38 highlighted the plasma cells. The mean Ki67 % was found to be significantly higher (19.6 % range 2-40 %) in poorly differentiated morphology compared to well differentiated morphology (4.06 % range 0.2-20 %) (p = 0.003). The mean MVD in the well differentiated morphology was 10.6 (range 1.2-47.4) compared to 20.3 (range 6.9-39.6) in the poorly differentiated morphology (p = 0.04). The mean MVD was 5.7 (range 1.2-12.8) in the interstitial pattern of infiltration compared to 20.04 (2.9-47.4) in the diffuse pattern (p < 0.0001). The mean MVD was 6.4 in cases with serum albumin >3.5 gm/dl compared to 13.3 in cases with serum albumin <3.5 gm/dl (p = 0.009). Both the Ki67 and MVD showed an increasing trend with the clinical staging. Thus the study of proliferation and angiogenesis in bone marrow biopsy is useful for prognosticating patients with multiple myeloma.

Expression of Proliferating Cell Nuclear Antigen (PCNA) in Multiple Myeloma: Its Relationship to Bone Marrow Microvessel Density and other Factors of Disease Activity

The expression of the proliferating cell nuclear antigen (PCNA) was studied in plasma cells in bone marrow biopsies from patients with multiple myeloma (MM) using a double immunostaining method. In the same samples, microvessel density (MVD), after staining with anti-CD34 antibodies, was determined before and after chemotherapy. The correlation of PCNA expression and MVD with other myeloma parameters (clinical stage, bone marrow plasma cell infiltration and serum interleukin –6 (IL-6)) was also investigated.

The study population included 51 newly diagnosed MM patients, 12 patients in plateau phase after treatment and 15 normal controls. Pretreatment mean ± SE values of PCNA, MVD, plasma cell infiltration and serum IL-6 were significantly higher than post treatment values and controls. Pretreatment PCNA expression correlated significantly with bone marrow MVD (p<0.05) plasma cell infiltration (p<0.01) and IL-6 (p<0.01).

These findings show that the proliferative activity of plasma cells is related to the angiogenic activity in the bone marrow of multiple myeloma patients. Both PCNA and MVD correlate with markers of disease activity thus may provide additional information when included in the initial evaluation of myeloma bone marrow biopsies.

Relationship between circulating BAFF serum levels with proliferating markers in patients with multiple myeloma

In multiple myeloma, there are many factors influencing the growth of the malignant clone in direct and indirect manners. BAFF is a growth factor for myeloma cells. The aim of the study was to measure its circulating levels in 54 pretreatment patients, along with serum levels of other proliferation markers, such as interleukins-6, -10, and -15, CRP, and beta-2 microglobulin, as well as bone marrow plasma cell infiltration and expression of Ki-67 PI, in various stages of the disease and after effective treatment in 28 of them. Serum levels of the previously mentioned factors were measured by ELISA, whereas bone marrow plasma cell infiltration and Ki-67 expression were estimated immunohistochemically. All measured parameters were higher in pretreated myeloma patients compared to healthy population and were also increasing with the progression of the disease. They all also decreased after effective therapy. Furthermore, all pretreatment values correlated to each other. BAFF seems to be an important growth factor for myeloma plasma cells. Measuring its serum levels, along with the previously mentioned cytokines, may provide important information regarding the degree of myeloma cells' proliferation. Therefore, they all could be used as markers of proliferation and disease activity.

Lack of correlation between angiogenic cytokines and serum insulin-like growth factor-1 in patients with multiple myeloma

There are many growth factors influencing the expansion of multiple myeloma (MM). Angiogenesis is a process that may enhance MM growth, in various manners. Among them, insulin-like growth factor-1 (IGF-1) is a major factor, acting in many levels. The aim of the study was to measure serum levels of IGF-1 in newly diagnosed MM patients and to correlate them with clinical stage of the disease and with markers of angiogenesis, such as vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), and interleukin-6 and 15 (IL-6 and IL-15). Serum levels of the above factors were measured, by ELISA, in 57 newly diagnosed MM patients and in 20 healthy controls. There was no difference in serum levels of IGF-1 in MM patients and in controls, contrary to angiogenic factors, which were higher in MM patients (p < 0.001). Similarly, IGF-1 did not correlate with clinical stage of the disease nor the other angiogenic factors, which also correlated with each other (p < 0.001). Serum IGF-1 concentrations are not influenced in MM patients. Therefore, although it is a proliferation cytokine, it cannot be used as marker of disease activity.

Clinical significance of sCD105 in angiogenesis and disease activity in multiple myeloma

BACKGROUND

Τhe importance of angiogenesis in malignancies' growth is well recognized. CD105 (Endoglin), a proliferation-associated glycoprotein, is a powerful marker of neovascularization. Elevated amounts of soluble CD105 (sCD105) have been identified in selected solid tumors. The aim of the study was to estimate circulating levels of sCD105 and soluble transforming growth factor-β(1) (sTGF-β(1)), in multiple myeloma (MM) patients, to determine their significance in tumor progression and to investigate the correlation between sCD105 and markers of disease activity.

METHODS

We studied 50 newly diagnosed MM patients. Twenty-five of them were also investigated in plateauphase. Twenty patients with monoclonal gammopathy of undetermined significance (MGUS) were enrolled in this study. As control group 28 healthy persons were studied. We determined sCD105, sTGF-β(1) and interleukin-6 (IL-6) in the serum, Ki-67 proliferation index (Ki-67 PI) expression and microvascular density(MVD) in bone marrow with immunohistochemistry.

RESULTS

The mean concentrations of sCD105 and IL-6 were higher in MM and MGUS patients compared to controls, whereas serum levels of sTGF-β(1) were lower in MM patients compared to MGUS patients and controls. sCD105 levels, were significantly different among disease stages, with higher values in advanced stages. It was found that sCD105 correlated with Ki-67 PI, MVD and IL-6.

CONCLUSIONS

CD105 seems to play an important role in angiogenesis and tumor progression. Circulating levels of sCD105 could detect patients with more advanced disease and might help in evaluating the response to treatment.

Hematologic neoplasias and acromegaly

We report a 59-year-old acromegalic woman, who presented with generalized bone pain, weakness, fatigue and foamy urine, who was found to have multiple myeloma (MM); and a 60-year-old acromegalic woman with dizziness, vomiting and abdominal pain, high blood pressure and splenomegaly that was posteriorly diagnosed as having Waldenstrom's macroglobulinemia (WM). Acromegaly is an uncommon disease and epidemiological studies have provided increasingly debated evidence that elevated IGF-I levels might enhance the neoplastic risk, and that cancers constitute the third leading cause of mortality in acromegaly. It is known that GH and IGF-I can activate B cell lymphocytes, and that IGF-I receptor is universally expressed in MM cells. Although the complication of acromegaly with WM or MM in patients has rarely been reported until now, we described two case reports of acromegalic patients with those hematological neoplasias, which allow a discussion about this controversial issue.

The microenvironment and molecular biology of the multiple myeloma tumor

Multiple myeloma (MM) is a deadly plasma cell cancer that resides in the bone marrow (BM). Numerous studies have demonstrated the involvement of the BM microenvironment supporting tumor growth, angiogenesis, bone disease and drug resistance. Reciprocal interactions between the different components of the BM microenvironment and the MM cells are necessary to regulate migration, differentiation, proliferation and survival of the malignant plasma cells. In this review we focus on the interactions and molecular mechanisms by which the BM microenvironment exert these effects. Better understanding of these interactions and the study of the epigenetic changes that tumor cells undergo are necessary in order to improve current treatments and for the discovery of new therapies that may eventually lead to a potential cure.

The relation between bone marrow angiogenesis and the proliferation index Ki-67 in multiple myeloma

AIM

Angiogenesis correlates with disease progression in various haematological malignancies. This study investigated the association between microvascular density (MVD) and the Ki-67 proliferation index (Ki-67 PI), bone marrow infiltration, and C reactive protein (CRP) in patients with multiple myeloma.

METHODS

Bone marrow MVD was examined in 44 biopsies at diagnosis and 15 in plateau phase by immunostaining the endothelial cells with a monoclonal antibody to CD34. The Ki-67 PI was evaluated by a double immunostaining technique using the monoclonal antibodies MIB-1 and CD38.

RESULTS

MVD, Ki-67 PI, bone marrow infiltration, and CRP were significantly higher in pretreatment patients than in controls and decreased in patients achieving plateau phase. MVD significantly correlated with Ki-67 PI and infiltration, and Ki-67 correlated with infiltration.

CONCLUSION

In multiple myeloma, apart from being a marker of proliferative activity, Ki-67 is also associated with bone marrow angiogenesis and tumour burden.

Ki-67 Proliferation Index

The nuclear protein Ki-67 is a proliferation index, as it is expressed only by dividing cells. In this study, we investigated the clinical significance of Ki-67 determination on bone marrow biopsies of 35 patients with newly diagnosed multiple myeloma (MM). We examined the correlation of Ki-67 with other MM proliferation-related factors: interleukin-6 (IL-6), IL-10, bone marrow infiltration by plasma cells, serum lactate dehydrogenase (LDH), and beta 2 microglobulin (b2M). Ki-67 expression was also correlated with the survival rate of the patients. The results showed that Ki-67 expression increases with increasing stage of disease according to Durie-Salmon (classification stage III vs. I and II, p < 0.001). Furthermore, infiltration, IL-6, LDH, and b2M increase significantly with advancing stage of disease (p < 0.004). All parameters studied were significantly higher in patients versus controls. Ki-67 correlated with IL-6 (r: 0.422, p < 0.01), LDH (r: 0.437, p < 0.01), and b2M (r: 0.478, p < 0.004). There was a marked difference in survival between patients with MM with Ki-67 greater than 8% and patients with Ki-67 less than 8%, in favor of the latter (p < 0.07). We conclude that Ki-67 determination during routine pathological analysis of bone marrow in newly diagnosed MM could provide useful information about the proliferative activity and prognosis of the disease.

Insulin-like growth factor I is a dual effector of multiple myeloma cell growth

Multiple myeloma (MM) is an invariably fatal disease that accounts for approximately 1% to 2% of all human cancers. Surprisingly little is known about the cellular pathways contributing to growth of these tumors. Although the cytokine interleukin-6 has been suggested to be the major stimulus for myeloma cell growth, the role of a second potential growth factor, insulin-like growth factor I (IGF-I), has been less clearly defined. The IGF-I signaling cascade in 8 MM cell lines was examined. In 7 of these, the IGF-I receptor (IGF-IR) was expressed and autophosphorylated in response to ligand. Downstream of IGF-IR, insulin receptor substrate 1 was phosphorylated, leading to the activation of phosphatidylinositol-3′-kinase (PI-3K). PI-3K, in turn, regulated 2 distinct pathways. The first included Akt and Bad, leading to an inhibition of apoptosis; the second included the mitogen-activated protein kinase (MAPK), resulting in proliferation. Biologic relevance of this pathway was demonstrated because in vitro IGF-I induced both an antiapoptotic and a proliferative effect. Importantly, in vivo administration of IGF-I in SCID mice inoculated with the OPM-2 line led to approximately twice the growth rate of tumor cells as in controls. These results suggest that IGF-I activates at least 2 pathways effecting myeloma cell growth and contributes significantly to expansion of these cells in vivo.

Insulin-like growth factor I is a dual effector of multiple myeloma cell growth

Multiple myeloma (MM) is an invariably fatal disease that accounts for approximately 1% to 2% of all human cancers. Surprisingly little is known about the cellular pathways contributing to growth of these tumors. Although the cytokine interleukin-6 has been suggested to be the major stimulus for myeloma cell growth, the role of a second potential growth factor, insulin-like growth factor I (IGF-I), has been less clearly defined. The IGF-I signaling cascade in 8 MM cell lines was examined. In 7 of these, the IGF-I receptor (IGF-IR) was expressed and autophosphorylated in response to ligand. Downstream of IGF-IR, insulin receptor substrate 1 was phosphorylated, leading to the activation of phosphatidylinositol-3′-kinase (PI-3K). PI-3K, in turn, regulated 2 distinct pathways. The first included Akt and Bad, leading to an inhibition of apoptosis; the second included the mitogen-activated protein kinase (MAPK), resulting in proliferation. Biologic relevance of this pathway was demonstrated because in vitro IGF-I induced both an antiapoptotic and a proliferative effect. Importantly, in vivo administration of IGF-I in SCID mice inoculated with the OPM-2 line led to approximately twice the growth rate of tumor cells as in controls. These results suggest that IGF-I activates at least 2 pathways effecting myeloma cell growth and contributes significantly to expansion of these cells in vivo.

Serum interleukin-6 has no discriminatory role in paraproteinaemia nor a prognostic role in multiple myeloma

We determined interleukin-6 (IL-6) levels in the serum of 212 well-defined patients with newly diagnosed paraproteinaemia and evaluated its discriminatory value and prognostic role in multiple myeloma (MM). Results were compared with serum neural cell adhesion molecule and beta-2-microglobulin, both established prognostic MM markers. Paraproteinaemia-related diagnoses were: MM (60), other haematological diseases (46), solid tumours (35), autoimmune diseases (17) and monoclonal gammopathy of unknown significance (MGUS) (54). The range of IL-6 levels in all diagnostic groups overlapped widely and did not serve as a discriminatory marker in newly diagnosed paraproteinaemia even when patients with infection or fever (42) were excluded. In MM high IL-6 levels (>/= 50 pg/ml) were not associated with a shorter survival (P = 0.24). We compared our results with 20 published studies on serum IL-6 in paraproteinaemia and/or MM. IL-6 data have to be related to the assay used (bio- or immunoassay) and to the status of MM (newly diagnosed, during therapy, progressive disease). We conclude that serum IL-6 is not specific for paraproteinaemia-related diseases and will not serve as a reliable discriminatory or prognostic marker in paraproteinaemia and MM.

Circulating IL-6-type cytokines and sIL-6R in patients with multiple myeloma

We investigated the serum concentration of interleukin-6 (IL-6) and four IL-6 family cytokines - oncostatin M (OSM), leukaemia inhibitory factor (LIF), interleukin-11 (IL-11) and ciliary neurotrophic factor (CNTF) as well as IL-6 soluble receptor (sIL-6R) - using an enzyme-linked immunosorbent assay (ELISA) in 67 patients with multiple myeloma (MM) and 24 healthy controls, for a possible association between the serum levels of these peptides with disease activity and known prognostic factors. sIL-6R was detectable in all 67 and IL-6 in 65 (97%) patients. Both peptides were measurable in all healthy controls. In contrast, OSM was detectable in 30 (44.8%) MM patients and in only four (16.6%) normal individuals. The serum levels of IL-6, OSM and sIL-6R were significantly higher in MM patients compared with control group (P < 0.001, P < 0.03 and P < 0. 001 respectively). The highest concentrations of these cytokines were found in patients with progressive disease and the lowest in MM patients with stable disease and in healthy persons. LIF was detectable in four (6%), CNTF in 28 (41.8%) and IL-11 in eight (11. 9%) of the patients with MM. In the control group LIF, CNTF and IL-11 were measurable in 8.3%, 33.3% and 8.3% respectively. The serum concentration of these cytokines did not correlate either with clinical stage or with the phase of disease and was similar to those in healthy individuals. We found significant positive correlation between IL-6 levels and OSM (P < 0.001). We also observed positive correlation between beta2-M concentration and serum levels of IL-6 (P < 0.002), sIL-6R (P < 0.02) and OSM (P < 0.04) as well as a positive relationship between CRP and IL-6 (P < 0.001) and OSM (P < 0.002). In conclusion, the serum levels of IL-6, OSM and sIL-6R, but not LIF, IL-11 and CNTF, may be useful markers of MM activity.

Cytokine expression in multiple myeloma and monoclonal gammopathy: analysis by reverse transcription/polymerase chain reaction and quantitative PCR

Cytokine messenger RNA expression was studied using the reverse transcription/polymerase chain reaction in 23 patients with multiple myeloma (MM), 16 with monoclonal gammopathy of undetermined significance (MGUS), 12 with post menopausal osteoporosis, (OP) and 12 normal controls. Messenger RNAs for IL-1 alpha, IL-1 beta, TNF-alpha, TNF-beta, IL-6 and M-CSF were sought in view of their reported pathogenic role in myeloma. Transcripts for IL-1 beta, TNF-alpha, TNF-beta and M-CSF were found frequently in all four groups of patients. The only significant difference in cytokine expression between the groups was for IL-6 which was expressed in 17% of controls compared with 87% of patients with MM (p < 0.001), 62% of patients with MGUS (p < 0.02) and 67% of patients with osteoporosis (p < 0.02). Further analysis of IL-6 expression by quantitative PCR showed significantly higher IL-6 mRNA levels in MM compared with MGUS (p < 0.006). There was no correlation however between expression of individual cytokines and clinical features of myeloma such as osteolytic bone disease or hypercalcaemia. We conclude that expression of IL-6 mRNA is significantly enhanced in multiple myeloma when compared with MGUS. However, since MGUS and osteoporosis were also associated with a high prevalence of IL-6 expression when compared with controls it is probable that factors other than IL-6 are responsible for the local osteolytic lesions which characterise MM, but which are not seen in MGUS or osteoporosis.

Constituents of autocrine IL-6 loops in myeloma cell lines and their targeting for suppression of neoplastic growth by antibody strategies

We examined the constitution and biological relevance of an autocrine IL-6/IL6-receptor (r) loop in 7 multiple myeloma and plasma-cell leukemia lines in order to determine its biological role and potential therapeutic impact on antibody strategies. The expression and constitution of the IL-6r [i.e. membrane-bound gp-80, soluble (s)gp-55 and the gp-130 IL-6 signal-transducing element (str)], the binding capacity of the membrane-associated receptor(s) for IL-6, the production and secretion of IL-6 by neoplastic plasma cells, and the effect of IL-6 on tumor-cell proliferation were investigated. In the U-266 cell line, the growth-inhibitory effects of antibodies (Abs) against IL-6 and IL-6-binding subunit of its receptor were compared with each other. From our results the following conclusions may be drawn: (i) Substantial differences in the quantificative assembly of the IL-6r constituents and in the response to recombinant (r) human (h) IL-6 became evident in the 7 myeloma cell lines. (ii) The components of an autocrine IL-6 loop may be regulated in an independent and, in the case of IL-6 and sgp-55, probably counteractive manner. (iii) The level of endogenous IL-6 and the reservoir of recruitable sgp-55 were important for the response to exogenous rhIL-6. (iv) Apart from IL-6, other growth factors are important for the propagation of myeloma cells but at least some of them exert their effect through an IL-6-dependent pathway. Their growth-promoting activity, as well as that of IL-6, may be successfully targeted by immunological means, with Abs against the IL-6r being more efficient than those against the ligand.