CKS1B promotes cell proliferation and invasion by activating STAT3/PD-L1 and phosphorylation of Akt signaling in papillary thyroid carcinoma.

OBJECTIVE: To investigate role of GKS1B and its relationship between STAT3/PD-L1 and p-Akt in papillary thyroid carcinoma (PTC). METHODS: Expression of GKS1B and PD-L1 was determined in PTC cell lines. GKS1B was overexpressed or knocked down by transfection with overexpression plasmids or si-CKS1B. STAT3 inhibitor WP1066 was used to suppress STAT3, and PD-L1 inhibitor Pembrolizumab was used to block PD-L1. Cell viability and invasion were evaluated by MTT and transwell assay, respectively. The expression of STAT3, p-STAT3, Akt, and p-Akt was measured using Western blotting. RESULTS: Both protein levels and mRNA levels of CKS1B and PD-L1 were remarkably up-regulated in PTC cell lines. Knockdown of CKS1B significantly inhibited cell viability and invasion of PTC cells and suppressed STAT3/PD-L1 signaling and Akt phosphorylation, while overexpression of CKS1B led to opposite results. Inhibition of STAT3 or PD-L1 reversed the effects of overexpressed CKS1B on PTC cells. CONCLUSION: The overexpression of CSK1B could promote cell viability and invasion of PTC cells through activation of STAT3/PD-L1 signaling and Akt phosphorylation.

Outcome of Multiple Myeloma with Chromosome 1q Gain and 1p Deletion after Autologous Hematopoietic Stem Cell Transplantation: Propensity Score Matched Analysis.

The gain/amplification CKS1B gene at chromosome region 1q21 (1q+) is one of the most common genetic aberrations in multiple myeloma (MM). Amplification of CKS1B is frequently associated with the deletion of the CDKN2C gene at chromosome region 1p32 (1p-), which is also associated with inferior outcomes. In this retrospective study, we evaluated the outcomes of patients with 1q+ and/or 1p- after high-dose therapy and autologous hematopoietic cell transplantation (auto-HCT). From January 2006 to December 2015, 1491 newly diagnosed patients with MM underwent upfront high-dose therapy and auto-HCT at our institution. Of those, 899 had the fluorescent in situ hybridization (FISH) data available. FISH was performed at diagnosis and before the start of induction in 686 (76%) patients and after the initiation of induction therapy in 213 (24%) patients. We identified 100 patients with 1q+ and/or 1p- by FISH from the cohort of 899 patients. A control group (n = 287) with diploid cytogenetics and normal FISH panel was selected from the same cohort. From the above 2 cohorts, using a propensity score matched analysis, we identified matched controls for 85 of the 100 patients with 1q+/1p-. Patients were matched for age at auto-HCT, sex, International Staging System stage, induction regimen, creatinine level, disease status at auto-HCT, conditioning regimen, and maintenance therapy. Sixty-seven (79%), 4 (5%), and 14 (16%) patients had 1q+, 1p-, or both 1q+ and 1p-, respectively. There was no significant difference in induction therapy, preparative regimen, or maintenance therapy between the 1q+/1p- and the control group. The median follow-up time for all patients was 29.2 months (range, 0.29 to 84.96). The cumulative incidence of 100-day nonrelapse mortality was 1.2% and 0% for the 1q+/1p- and the control group, respectively. Forty-two patients (50%) in the 1q+/1p- group achieved complete response compared with 40 patients (47%) in the control group. The estimated 3-year progression-free survival (PFS) and overall survival (OS) rates were 41% and 79% for the 1q+/1p- group and 56% and 86% for the control group. Patients in the 1q+/1p- group were at significantly increased risk of progression or death compared to the control group (hazard ratio [HR], 2.21; confidence interval [CI], 1.18 to 4.16; P = .014). No significant association between OS in the 2 groups was observed. The outcome of the 1q+/1p- alone (with no additional high-risk cytogenetics) and the propensity score matched control groups was also compared. Median PFS for the 1q+/1p- alone subgroup was 26.6 months, compared with 38.8 months for the control group (HR, 1.9; CI, 0.9 to 4.08; P = .09). The median OS had not been reached for the 1q+/1p- alone subgroup and was 81.1 months for the control group (HR, 1.25; CI, 0.3 to 4.6; P= .73). 1q+/1p- abnormalities with amplification of CKS1B and deletion ofCDKN2Cgenes were associated with shorter PFS compared with a propensity score matched group of patients with diploid cytogenetics and normal a FISH panel. The outcomes of 1q+/1p- patients with MM have improved with the use of more effective induction, conditioning, and maintenance therapy compared with historical controls, but we still need more effective therapeutic approaches to fully overcome the negative impact of 1q+/1p-.

The Cks1/Cks2 axis fine-tunes Mll1 expression and is crucial for MLL-rearranged leukaemia cell viability.

The Cdc28 protein kinase subunits, Cks1 and Cks2, play dual roles in Cdk-substrate specificity and Cdk-independent protein degradation, in concert with the E3 ubiquitin ligase complexes SCFSkp2 and APCCdc20. Notable targets controlled by Cks include p27 and Cyclin A. Here, we demonstrate that Cks1 and Cks2 proteins interact with both the MllN and MllC subunits of Mll1 (Mixed-lineage leukaemia 1), and together, the Cks proteins define Mll1 levels throughout the cell cycle. Overexpression of CKS1B and CKS2 is observed in multiple human cancers, including various MLL-rearranged (MLLr) AML subtypes. To explore the importance of MLL-Fusion Protein regulation by CKS1/2, we used small molecule inhibitors (MLN4924 and C1) to modulate their protein degradation functions. These inhibitors specifically reduced the proliferation of MLLr cell lines compared to primary controls. Altogether, this study uncovers a novel regulatory pathway for MLL1, which may open a new therapeutic approach to MLLr leukaemia.

Regulation of Transient Site-specific Copy Gain by MicroRNA.

Intra-tumor copy number heterogeneity is commonly observed in cancer; however, the molecular mechanisms that contribute to heterogeneity remain poorly understood. Up-regulation of the histone demethylase KDM4A promotes transient site-specific copy gain (TSSG) in cells; therefore, uncovering how KDM4A levels are controlled is important for understanding the regulation of copy number heterogeneity. Here, we demonstrate that KDM4A is regulated by hsa-mir-23a-3p, hsa-mir-23b-3p, and hsa-mir-137. Altering expression of these microRNAs (miRNAs) regulates KDM4A-dependent TSSG. miRNA inhibition promoted copy gains and increased expression of the drug-resistant oncogene CKS1B, which was further substantiated in primary breast tumors. Consistent with increased CKS1B expression, miRNA inhibition reduced breast cancer cell sensitivity to cisplatin. Our data identify these miRNAs as regulators of TSSG and copy gains of a drug resistance gene.

Outcome of Patients with Multiple Myeloma and CKS1B Gene Amplification after Autologous Hematopoietic Stem Cell Transplantation.

The gain/amplification of the CKS1B gene on chromosome 1q21 region is associated with a poor outcome in patients with multiple myeloma (MM). However, there are limited data on the outcome of patients with CKS1B amplification after a single high-dose chemotherapy and autologous hematopoietic stem cell transplantation (auto-HCT). We retrospectively evaluated the outcome of patients with CKS1B amplification who received an auto-HCT between June 2012 and July 2014 at our institution. We identified 58 patients with MM and CKS1B gene amplification detected by fluorescent in situ hybridization (FISH). We compared their outcomes with a propensity score-matched control group of 58 patients without CKS1B amplification who were treated at approximately the same time. The primary objective was to compare the progression-free (PFS) and overall survival (OS) between the CKS1B and the control groups. Stratified log-rank test with the matched pairs as strata and double robust estimation under the Cox model were used to assess the effect of CKS1B gene amplification on PFS or OS in the matched cohort. Patients in the CKS1B and control groups were well matched for age, gender, disease status, year of auto-HCT, response to pretransplantation therapy, and baseline hemoglobin level. In both groups, 57% patients were in first remission and 43% had relapsed disease at auto-HCT. Twenty-seven (47%) patients with CKS1B amplification had concurrent monosomy 13 or 13q deletion; 6 (10%) by conventional cytogenetics only, 16 (28%) by FISH only, and 5 (9%) by both. Median follow-up after auto-HCT was 25.4 months. The median PFS of the CKS1B and the control groups were 15.0 months and 33.0 months (P = .002), respectively. The median OS have not been reached yet. The 2-year OS rates in the CKS1B and the control groups were 62% and 91% (P = .02), respectively. In conclusion, Patients with CKS1B amplification are more likely to have additional high-risk cytogenetic abnormalities and a shorter PFS and OS after an auto-HCT.

Quantitative analysis of CKS1B mRNA expression and copy number gain in patients with plasma cell disorders.

In this study, we have examined CKS1B gene expression and copy number in a total of 114- patients at diagnosis: 83 with multiple myeloma (MM) and 31 with monoclonal gammopathy of undetermined significance (MGUS). Results were correlated with cytogenetics, FISH and clinical characteristic. Significant CKS1B mRNA levels in MM compared to MGUS cases (p<0.048) were detected. In MM, the frequency of 1q21 (CKS1B) copy gain was significantly higher in cases with abnormal karyotype compared to patients with normal karyotype (p=0.021). Global analysis showed a positive correlation between CKS1B expression and 1q21 copy number (p<0.0001). No association between CKS1B mRNA expression and clinical parameters was found. However, a significantly higher level of ß2 microglobulin in cases with 1q21 gains than those without (p=0.0094) was observed. Overall survival was shorter in cases with 1q21 gain compared to those with normal 1q21 region (p=0.0082). Our results suggest a role for CKS1B in the multiple step process of progression of MGUS to MM and show that CKS1B copy gain has a more significant prognostic value than its overexpression. This adverse impact on survival probably reflects the genetic instability associated to chromosome 1q alterations resulting in a more aggressive behavior of the disease.

The HH-GLI2-CKS1B network regulates the proliferation-to-maturation transition of cardiomyocytes.

Cardiomyocyte (CM) proliferation and maturation are highly linked processes, however, the extent to which these processes are controlled by a single signaling axis is unclear. Here, we show the previously undescribed role of Hedgehog (HH)-GLI2-CKS1B cascade in regulation of the toggle between CM proliferation and maturation. Here we show downregulation of GLI-signaling in adult human CM, adult murine CM, and in late-stage hiPSC-CM leading to their maturation. In early-stage hiPSC-CM, inhibition of HH- or GLI-proteins enhanced CM maturation with increased maturation indices, increased calcium handling, and transcriptome. Mechanistically, we identified CKS1B, as a new effector of GLI2 in CMs. GLI2 binds the CKS1B promoter to regulate its expression. CKS1B overexpression in late-stage hiPSC-CMs led to increased proliferation with loss of maturation in CMs. Next, analysis of datasets of patients with heart disease showed a significant enrichment of GLI2-signaling in patients with ischemic heart failure (HF) or dilated-cardiomyopathy (DCM) disease, indicating operational GLI2-signaling in the stressed heart. Thus, the Hh-GLI2-CKS1B axis regulates the proliferation-maturation transition and provides targets to enhance cardiac tissue engineering and regenerative therapies.

Involvement of CKS1B in the anti-inflammatory effects of cannabidiol in experimental stroke models.

We have previously demonstrated that treatment with cannabidiol (CBD) ameliorates mitochondrial dysfunction and attenuates neuronal injury in rats following cerebral ischemia. However, the role of CBD in the progression of ischemic stroke-induced inflammation and the molecules involved remain unclear. Here, we found that CBD suppressed the production of interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α), reduced the activation of microglia, ameliorated mitochondrial deficits, and decreased the phosphorylation of nuclear factor κ-B (NF-κB) in BV-2 cells subjected to oxygen-glucose deprivation/reoxygenation (OGD/R). Cyclin-dependent kinase regulatory subunit 1B (CKS1B) expression was decreased in BV-2 cells following OGD/R and this reduction was blocked by treatment with CBD. Knockdown of CKS1B increased the activation of microglia and enhanced the production of IL-1ß and TNF-α in BV-2 cells treated with CBD. Moreover, CKS1B knockdown exacerbated mitochondrial deficits and increased NF-κB phosphorylation. CBD treatment also ameliorated brain injury, reduced neuroinflammation, and enhanced the protein levels of mitochondrial transcription factor A and CKS1B in rats following middle cerebral artery occlusion/reperfusion. These data identify CKS1B as a novel regulator of neuroinflammation; and reveals its involvement in the anti-inflammatory effects of CBD. Interventions targeting CKS1B expression are potentially promising for treating in ischemic stroke.

[Retracted] Circular RNA NOX4 promotes the development of colorectal cancer via the microRNA­485­5p/CKS1B axis.

Following the publication of the above paper, it was drawn to the Editor's attention by a concerned reader that there appeared to be a matching data panel comparing between one of the Transwell invasion assay experiments (the 'SW620/si­NC' data panel) shown in Fig. 2F and Fig 6D in the following paper, written by different authors at different research institutes, that had already been published at the time of this paper's submission: Wang D, Yang T, Liu J, Liu Y, Xing N, He J, Yang J and Ai Y: Propofol inhibits the migration and invasion of glioma cells by blocking the PI3K/AKT pathway through miR­206/ROCK1 axis. Onco Targets Ther 13: 361­370, 2020. In addition, a potential problem regarding the design of the experiment was noted with the selection of the primers for the amplification of the miRNA miR­485­5p. Owing to the fact that the contentious data in the above article had already been published prior to its submission to Oncology Reports, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [Oncology Reports 44: 2009­2020, 2020; DOI: 10.3892/or.2020.7758].

A novel human multiple myeloma cell line with a 1q21 gain genetic abnormality and CKS1B overexpression.

Background: Multiple myeloma (MM) is an incurable hematologic malignancy mainly due to its cytogenetic abnormalities. Therefore, it is important to establish permanent malignant MM cell lines as tools to develop more effective therapies. Methods: Pleural effusion cells of a 70-year-old patient was collected to establish the CZ2 cell line. Characterization of CZ2 was determined with nephelometry, flow cytometry, fluorescence in situ hybridization (FISH), and chromosomal microarray analysis (CMA). Western blotting analysis was adopted to determine protein expression. Cell viability was measured by the 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Results: We established and characterized a new MM cell line, CZ2. Using nephelometry and flow cytometry, cells with typical plasma cell morphology but not classical plasma cell phenotype were found to be non-immunoglobulin-secretary cells. FISH analysis of cells revealed a unique characteristic, namely, that there was only gain of the 1q21 region (1q21+). No other common cytogenetic abnormalities in MM, such as deletion of 17p (17p-), deletion of 13q (13q-), or translocation of immunoglobulin heavy chain (IgH), were observed. In addition, the original cell line maintains its single cytogenetic abnormality. Meanwhile, we observed through western blotting that CDC28 protein kinase regulatory subunit 1B (CKS1B), an adverse prognostic gene located in the 1q21 region, was highly expressed in CZ2. Knockdown of CKS1B reduced cell viability and also increased the levels of cleaved-poly(ADP-ribose) polymerase (cleaved-PARP) and cleaved-caspase3. Conclusions: CZ2 provides a suitable material for cellular and molecular studies of MM with only a 1q21 abnormality. This cell line is characterized by a gain of 1q21, and the high expression of CKS1B is an important model for studies of myeloma cell growth and drug resistance during therapy.

Identification of CKS1B as a prognostic indicator and a predictive marker for immunotherapy in pancreatic cancer.

As a regulatory subunit of cyclin kinase, CKS1B promotes cancer development and is associated with poor prognosis in multiple cancer patients. However, the intrinsic role of CKS1B in pancreatic cancer remains elusive. In our research, CKS1B expression in pancreatic tumor tissue was higher than that in normal tissue by TCGA, Oncomine and CPTAC databases analysis. Similar result was verified in our center tissues by qRT-PCR. CKS1B expression was closely relevant to histologic grading, prognosis, and TMB. GSEA showed that CKS1B mainly participated in the regulation of autophagy and T cell receptor signaling pathway. Furthermore, CIBERSORT analysis showed that there was a strong correlation between CKS1B expression and tumor immune cells infiltration. Drug sensitivity analysis showed that patients with high CKS1B expression appeared to be more sensitive to gemcitabine, 5-fluorouracil, and paclitaxel. We then investigated cell viability and migratory ability by CCK8 and transwell assay, respectively. Results indicated that CKS1B knockdown by short hairpin RNA significantly reduced pancreatic cancer cell viability and invasion via regulating PD-L1 expression. In conclusion, our research further demonstrates the role of CKS1B in pancreatic cancer and the signaling pathways involved. The association of CKS1B with immune infiltration and immune checkpoint may provide a new direction for immunotherapy of pancreatic cancer.

CKS1B promotes the progression of hepatocellular carcinoma by activating JAK/STAT3 signal pathway.

Hepatocellular carcinoma (HCC) is a malignancy of considerable concern due to its continuous increase in morbidity and mortality. This study attempts to identify the molecules that play a key role in the progression of HCC, explore its potential mechanism, and provide more target choices for targeted therapy. Using overexpression plasmid and shRNA, CKS1B was respectively overexpressed and knocked down to explore its biological function roles in HCC progression and development. MTT and colony formation assays showed that knockdown of CKS1B inhibited the survival and proliferation of HCC cell lines (Hep3B and Huh7). The flow cytometry and western blot analysis showed that knockdown of CKS1B significantly induced the apoptosis of Hep3B and Huh7 cells. The wound healing and transwell invasion assays showed that knockdown of CKS1B had a significant inhibitory effect on the migration and invasion of Hep3B and Huh7 cells. These functional tests confirmed that CKS1B acts as an oncogene that regulates the malignant progression of HCC. Moreover, this study also demonstrated that knockdown of CKS1B inhibited the activation of JAK/STAT3 pathway, evidenced by the significantly downregulated p-STAT3 protein expression. Furthermore, knockdown of CKS1B also downregulated STAT3 target genes TIMP-1, Bcl-2 and VEGF, which were involved in controlling cell apoptosis and migration. On the contrary, overexpression of CKS1B caused the completely opposite results. Taken together, CKS1B acts as an oncogene to promote the proliferation and metastasis of HCC cells by activating JAK/STAT3 signaling pathway.

Role of 1q21 in Multiple Myeloma: From Pathogenesis to Possible Therapeutic Targets.

Multiple myeloma (MM) is characterized by an accumulation of malignant plasma cells (PCs) in the bone marrow (BM). The amplification of 1q21 is one of the most common cytogenetic abnormalities occurring in around 40% of de novo patients and 70% of relapsed/refractory MM. Patients with this unfavorable cytogenetic abnormality are considered to be high risk with a poor response to standard therapies. The gene(s) driving amplification of the 1q21 amplicon has not been fully studied. A number of clear candidates are under investigation, and some of them (IL6R, ILF2, MCL-1, CKS1B and BCL9) have been recently proposed to be potential drivers of this region. However, much remains to be learned about the biology of the genes driving the disease progression in MM patients with 1q21 amp. Understanding the mechanisms of these genes is important for the development of effective targeted therapeutic approaches to treat these patients for whom effective therapies are currently lacking. In this paper, we review the current knowledge about the pathological features, the mechanism of 1q21 amplification, and the signal pathway of the most relevant candidate genes that have been suggested as possible therapeutic targets for the 1q21 amplicon.

Gain/Amplification of Chromosome Arm 1q21 in Multiple Myeloma.

Multiple myeloma (MM), a plasma cell neoplasm, is an incurable hematological malignancy characterized by complex genetic and prognostic heterogeneity. Gain or amplification of chromosome arm 1q21 (1q21+) is the most frequent adverse chromosomal aberration in MM, occurring in 40% of patients at diagnosis. It occurs in a subclone of the tumor as a secondary genomic event and is more amplified as the tumor progresses and a risk factor for the progression from smoldering multiple myeloma to MM. It can be divided into either 1q21 gain (3 copies) or 1q21 amplification (≥4 copies), and it has been suggested that the prognosis is worse in cases of amplification than gain. Trisomy of chromosome 1, jumping whole-arm translocations of chromosome1q, and tandem duplications lead to 1q21+ suggesting that its occurrence is not consistent at the genomic level. Many studies have reported that genes associated with the malignant phenotype of MM are situated on the 1q21 amplicon, including CKS1B, PSMD4, MCL1, ANP32E, and others. In this paper, we review the current knowledge regarding the clinical features, prognostic implications, and the speculated pathology of 1q21+ in MM, which can provide clues for an effective treatment approach to MM patients with 1q21+.

CKS1B as Drug Resistance-Inducing Gene-A Potential Target to Improve Cancer Therapy.

Cancer is a threat to human health and life. Although previously centered on chemical drug treatments, cancer treatment has entered an era of precision targeted therapy. Targeted therapy entails precise guidance, allowing the selective killing of cancer cells and thereby reducing damage to healthy tissues. Therefore, the need to explore potential targets for tumor treatment is vital. Cyclin-dependent kinase regulatory subunit 1B (CKS1B), a member of the conserved cyclin kinase subunit 1 (CKS1) protein family, plays an essential role in cell cycling. A large number of studies have shown that CKS1B is associated with the pathogenesis of many human cancers and closely related to drug resistance. Here, we describe the current understanding of the cellular functions of CKS1B and its underlying mechanisms, summarize a recent study of CKS1B as a target for cancer treatment and discuss the potential of CKS1B as a therapeutic target.

Circular RNA NOX4 promotes the development of colorectal cancer via the microRNA­485­5p/CKS1B axis.

Colorectal cancer (CRC) is a common malignancy globally. The aim of the present study was to explore the role and the working mechanism of circular RNA NADPH oxidase 4 (circNOX4; circBase ID, hsa_circ_0023990) in CRC. Reverse transcription­quantitative (RT­q)PCR was used to examine the expression of circNOX4, NOX4 mRNA and microRNA (miR)­485­5p in CRC tissues and cell lines. 3­(4,5­Dimethylthiazol­2­yl)­2,5­diphenyltetrazolium bromide and Transwell assays were performed to analyze CRC cell viability and motility. The glycolytic ability of CRC cells was assessed by measuring glucose consumption, lactate production, extracellular acidification and O2 consumption rates using commercial kits. The starBase database was used to predict the targets of circNOX4 and miR­485­5p, and the interaction was confirmed by dual­luciferase reporter and RNA immunoprecipitation assays. A murine xenograft model was established to verify the role of circNOX4 in CRC in vivo. The results demonstrated that the expression of circNOX4 was upregulated in CRC tissues and cell lines compared with that in adjacent normal tissues and a normal colon epithelial cell line, respectively. The expression of circNOX4 was negatively associated with the prognosis of patients with CRC. CircNOX4 silencing suppressed the proliferation, migration, invasion and glycolysis of CRC cells. miR­485­5p was identified as a target of circNOX4. CircNOX4 promoted CRC progression by sponging miR­485­5p. miR­485­5p was demonstrated to bind to the 3' untranslated region (UTR) of CDC28 protein kinase regulatory subunit 1B (CKS1B). miR­485­5p overexpression­mediated malignant properties of CRC cells were partly reversed by the transfection with the CKS1B overexpression plasmid. CircNOX4 silencing restrained the CRC xenograft growth in vivo. Collectively, the results of the present study demonstrated that circNOX4 may serve an oncogenic role in CRC by promoting the proliferation, migration, invasion and glycolysis of CRC cells via the miR­485­5p/CKS1B axis.

Globular C1q Receptor (gC1qR/p32/HABP1) Suppresses the Tumor-Inhibiting Role of C1q and Promotes Tumor Proliferation in 1q21-Amplified Multiple Myeloma.

Immunodeficiencies are widely becoming known as important features of multiple myeloma (MM) and may promote the proliferation of malignant cells as well as confer resistance to therapy. Few studies focus on the immunomodulatory effects of the complement system on MM. This study aims to explore the role of C1q in MM patients. Plasma C1q was found to be significantly reduced in MM patients, and the amount of C1q deposited around the CD138+ cells in bone marrow (BM) biopsy sections was observed to be much higher, especially in the subgroup with 1q21 amplification (Amp1q21). CD138+ cells expressed higher levels of C1q receptors (C1qRs) than CD138- cells. Patients with Amp1q21 expressed higher levels of globular C1qR (gC1qR), whereas patients without Amp21 expressed higher levels of collagen tail C1qR (cC1qR). Additionally, gC1qR was noted to suppress the MM-inhibiting role of C1q in H929, U266, and MM1S. gC1qR interacts with insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3), which also suppressed the function of C1q and regulated CDC28 protein kinase regulatory subunit 1B (CKS1B) mRNA. In summary, gC1qR suppressed the MM-inhibiting role of C1q and regulated CKS1B mRNA in promoting tumor proliferation via IGF2BP3 in 1q21-amplified MM. Our findings provide novel evidence on how MM cells evade the immune system and promote survival as well as suggest possible novel targets for future therapies of MM.

MicroRNA-1258 Inhibits the Proliferation and Migration of Human Colorectal Cancer Cells through Suppressing CKS1B Expression.

Increasing evidence has demonstrated that increased expression of cyclin-dependent kinase regulatory subunit 1B (CKS1B) is associated with the pathogenesis of many human cancers, including colorectal cancer (CRC). However, the regulatory mechanisms underlying the expression of CKS1B in CRC are not completely understood. Here, we investigate the role played by microRNAs in the expression of CKS1B and carcinogenesis in CRC. Among the six microRNAs predicted to target CKS1B gene expression, only miR-1258 was revealed to downregulate CKS1B expression through binding to its 3'-UTR region, as ectopic miR-1258 expression suppressed CKS1B expression and vice versa. In CRC, miR-1258 expression also decreased cell proliferation and migration in vitro and tumor growth in vivo, similar to cells with silenced CKS1B expression. Considering the highly increased levels of CKS1B and decreased expression of miR-1258 in tumors from CRC patients, these findings suggest that miR-1258 may play tumor-suppressive roles by targeting CKS1B expression in CRC. However, the therapeutic significance of these findings should be evaluated in clinical settings.

3-O-(Z)-coumaroyloleanolic acid overcomes Cks1b-induced chemoresistance in lung cancer by inhibiting Hsp90 and MEK pathways.

Expression of CDC28 protein kinase regulatory subunit 1 (Cks1), an adaptor for cyclin-dependent kinases, is tightly regulated at transcriptional and posttranslational levels. Increased expression of Cks1 has been documented to be attributable to cancer progression, chemoresistance, and chemosensitivity. Here we report that ectopic overexpression of Cks1b in human lung cancer cells (Cks1b-OE) induces chemoresistance of the cells to cisplatin (CDDP) and doxorubicin (DOX) through mechanisms independent of its canonical Skp2-p27 pathway. Further dissection with application of shRNA and selective inhibitors reveals that Hsp90 and MEK1/2 are the critical components of the non-canonical pathways responsible for the Cks1b-induced chemoresistance. Interestingly, inhibition of either Hsp90 or MEK1/2 rendered a similar magnitude of antitumor activity by resensitization of the chemoresistant Cks1b-OE cells to CDDP and DOX, suggesting that both Hsp90 and MEK1/2 are essential to Cks1b for induction of chemoresistance. Moreover, 3-O-(Z)-coumaroyloleanolic acid (3-COA), an active ingredient of oleanolic acid in the leaves of E. oldhamii Maxim, that has been shown to have antitumor activity against A549 lung cancer cells, mimicked PU-H71, a Hsp90-specific inhibitor, in antitumor activity when used alone or in combination with CDDP or DOX in Cks1b-OE cells and recurrent primary human lung cancer cells both in vitro and in vivo, suggesting that 3-COA is a novel Hsp90 inhibitor. Our data report for the first time that Cks1b employs Hsp90 and MEK1/2 pathways in lung cancer cells to develop chemoresistance and identify 3-COA as a potential antitumor drug for clinical treatment of chemoresistant lung cancer.

Loss of miR-1258 contributes to carcinogenesis and progression of liver cancer through targeting CDC28 protein kinase regulatory subunit 1B.

Hepatocellular carcinoma (HCC) is the leading cause of cancer related death worldwide. The number of deaths is proportional to the global incidence, which highlights the aggressive tumor biology and lack of effective therapies. Dysregulation of microRNAs has been implicated in carcinogenesis and progression of liver cancer. Here, we identified that miR-1258 was significantly downregulated in HCC and associated with poor patients' survival. Overexpression of miR-1258 significantly inhibits liver cancer cell growth, proliferation and tumorigenicity through increasing cell cycle arrest in G0/G1 phase and promotes cell apoptosis. Interestingly, stable overexpression of miR-1258 suppresses cell migration, stemness and increases sensitivity of HCC cells to chemotherapy drug like doxorubicin. The CDC28 protein kinase regulatory subunit 1B (CKS1B) was identified as a functional downstream target of miR-1258. Re-expression of CKS1B overcomes miR-1258 induced apoptosis and increases stemness of HCC cells, suggesting that loss of miR-1258 contributes to carcinogenesis and progression of liver cancer through targeting CKS1B . Therefore, loss of miR-1258 may be a potential diagnostic and prognostic biomarker and blocking miR-1258-CKS1B axis is a potential therapeutic strategy in HCC.