MicroRNA-301b-3p accelerates the growth of gastric cancer cells by targeting zinc finger and BTB domain containing 4

MicroRNAs (miRNAs) have been found to be aberrantly expressed and exert essential roles in the tumorigenesis and progression of gastric cancer (GC). miR-301b-3p has been recognized as a cancer-related miRNA in lung cancer, bladder cancer and hepatocellular carcinoma. However, the function of miR-301b-3p in GC progression and its underlying mechanism have not been studied yet. In this study, we found that miR-301b-3p expression was up-regulated in GC tissues compared to adjacent noncancerous tissues. Furthermore, the elevated levels of miR-301b-3p were detected in GC cell lines (SGC-7901, AGS, MKN-45 and MGC-803) as compared with GES-1 cells. Interestingly, GC tissues from patients with tumor size ≥ 5 cm and advanced tumor stages showed obvious higher levels of miR-301b-3p compared to matched controls. Functionally, miR-301b-3p knockdown prominently inhibited cell proliferation, and induced cell cycle arrest at G1 phase and apoptosis in MGC-803 cells. Meanwhile, ectopic expression of miR-301b-3p conversely regulated these biological behaviors of MKN-45 cells. Next, we found that miR-301b-3p knockdown increased, whereas miR-301b-3p overexpression reduced the expression of zinc finger and BTB domain containing 4 (ZBTB4) in GC cells. Accordingly, luciferase reporter assay identified ZBTB4 as a direct target of miR-301b-3p. ZBTB4 overexpression markedly restrained the growth of MGC-803 cells. More importantly, ZBTB4 silencing partially reversed miR-301b-3p knockdown-induced tumor suppressive effects on MGC-803 cells. In conclusion, we firstly revealed that miR-301-3p was highly expressed in GC and contributed to tumor progression via attenuating ZBTB4, which might provide a novel molecular-targeted strategy for GC treatment.     

Recent advances with cyclin-dependent kinase inhibitors: therapeutic agents for breast cancer and their role in immuno-oncology

Introduction: Collaborative interactions between several diverse biological processes govern the onset and progression of breast cancer. These processes include alterations in cellular metabolism, anti-tumor immune responses, DNA damage repair, proliferation, anti-apoptotic signals, autophagy, epithelial-mesenchymal transition, components of the non-coding genome or onco-mIRs, cancer stem cells and cellular invasiveness. The last two decades have revealed that each of these processes are also directly regulated by a component of the cell cycle apparatus, cyclin D1.

Area covered: The current review is provided to update recent developments in the clinical application of cyclin/CDK inhibitors to breast cancer with a focus on the anti-tumor immune response.

Expert opinion: The cyclin D1 gene encodes the regulatory subunit of a proline-directed serine-threonine kinase that phosphorylates several substrates. CDKs possess phosphorylation site selectivity, with the phosphate-acceptor residue preceding a proline. Several important proteins are substrates including all three retinoblastoma proteins, NRF1, GCN5, and FOXM1. Over 280 cyclin D3/CDK6 substrates have b\een identified. Given the diversity of substrates for cyclin/CDKs, and the altered thresholds for substrate phosphorylation that occurs during the cell cycle, it is exciting that small molecular inhibitors targeting cyclin D/CDK activity have encouraging results in specific tumors.     

Effect of new curcumin‐containing nanostructured lipid dispersions on human keratinocytes proliferative responses

This study describes the production and characterization of nanostructured lipid dispersions (NLDs) containing curcumin (CUR) as new tools for curcumin topical delivery. Four types of NLDs based on monoolein in association with different emulsifiers were produced: Na cholate and poloxamer 407 (NLD1), poloxamer alone (NLD2), the mixture of Na cholate and Na caseinate (NLD3) and Na cholate alone (NLD4). Morphology and dimensional distribution of lipid dispersions were investigated by cryo‐TEM and photon correlation spectroscopy (PCS). In vitro studies based on Franz cell, membrane nylon and stratum corneum–epidermis (SCE) were carried out to compare the four NLDs in terms of cytotoxicity in human keratinocytes and CUR diffusion. Our PCS studies showed differences in particles diameter among the different NLDs. In addition, cytotoxicity results in HaCaT cells evidenced that NLD1 and NLD2 were toxic at doses over 1 μm . Therefore, cryo‐TEM was determined only for NLD3 and NLD4 showing that CUR did not affect their structure. Diffusion measurement in SCE and nylon membrane evidenced that CUR had a time‐delayed release for NLD4. The ‘wound healing’ effect of NLD3 and NLD4 with and without CUR analysed keratinocytes in vitro, and a clear inhibition of cell proliferation/migration by CUR was observed. This effect was mediated by the inhibition of cyclin D1 expression as a consequence of the impaired NFkB activation. This study confirms the antiproliferative properties of CUR and evidenced a new possible model of CUR topical delivery for hyperproliferative cutaneous diseases such as psoriasis.     

Downregulation of APRIN expression increases cancer cell proliferation via an interleukin-6/STAT3/cyclin D axis

APRIN is a putative tumor suppressor whose expression is low in a variety of cancer cells. While decreased expression of APRIN leads to increased cell proliferation, unfavorable diagnosis or metastases in various cancer types, there is limited knowledge on the cellular mechanism of APRIN in cellular responses. The effect of APRIN depletion on cancer cell proliferation was examined in the present study, and the IL-6/STAT3/cyclin D axis was identified as a novel regulatory mechanism. Stable depletion of APRIN in cancer cells resulted in increased cell proliferation. Cytokine array analysis of the cells revealed that downregulation of APRIN induced secretion of interleukin-6 (IL-6) with corresponding activation of STAT3, a downstream intracellular mediator. Levels of cyclin D1 were increased in cells with APRIN depletion and cyclin D1 expression was associated with increased STAT3 binding on cyclin D1 promoter sequence; assessed by chromatin immunoprecipitation assay. The addition of an IL-6 neutralizing antibody P620 to the cell culture attenuated STAT3 activation and cyclin D1 expression in APRIN-depleted cells with corresponding decrease in cell proliferation. These experiments suggest that APRIN regulates cancer cell proliferation via an IL-6/STAT3/cyclin D axis and that targeting this axis in APRIN-associated cancer might provide a novel therapeutic approach.     

Nuclear localization of epidermal growth factor receptor (EGFR) in ameloblastomas

Background: Ameloblastoma is a locally invasive neoplasm often associated with morbidity and facial deformities, showing increased Epidermal Growth Factor Receptor (EGFR) expression. Inhibition of EGFR was suggested as a treatment option for a subset of ameloblastomas. However, there are resistance mechanisms that impair anti-EGFR therapies. One important resistance mechanism for EGFR-inhibition is the EGFR nuclear localization, which activates genes responsible for its mitogenic effects, such as Cyclin D1.Methods: We assessed EGFR nuclear localization in encapsulated (unicystic, n = 3) and infiltrative (multicystic, n = 11) ameloblastomas and its colocalization with Cyclin D1 by using anti-EGFR and anti-lamin B1 double labeling immunofluorescence analyzed by confocal microscopy. Oral inflammatory fibrous hyperplasia and oral squamous cell carcinoma samples were used for comparison.Results: Twelve cases of ameloblastoma exhibited nuclear EGFR colocalization with lamin B1. This positive staining was mainly observed in the ameloblast-like cells. The EGFR nuclear localization was also observed in control samples. In addition, nuclear EGFR colocalized with Cyclin D1 in ameloblastomas.Conclusions: Nuclear EGFR occurs in ameloblastomas in association with Cyclin D1 expression, which is important in terms of tumor biology clarification and raises a concern about anti-EGFR treatment resistance in ameloblastomas.     

Mechanisms of therapeutic CDK4/6 inhibition in breast cancer

Cyclin dependent kinase (CDK) 4/6 inhibitors have advanced the treatment of metastatic breast cancer by targeting the cell cycle machinery, interrupting intracellular and mitogenic hormone signals that stimulate proliferation of malignant cells. Preclinical evidence demonstrated that derangements of cyclin D1, CDK4/6, and retinoblastoma expression are common in breast cancer, and suggested a therapeutic benefit from interrupting this axis required for cell cycle progression. Studies of cell lines and animal models of breast cancer have demonstrated the complex interplay between the cell cycle and estrogen receptor and human epidermal growth receptor 2 signaling, which informs our understanding of synergistic use of CDK4/6 inhibitors with endocrine therapy, as well as mechanisms of resistance to endocrine therapy. Interestingly, estrogen receptor activity leads to upregulation of cyclin D1 expression, but the estrogen receptor is also in turn activated by cyclin D1, independent of estrogen binding. Early CDK inhibitors were nonspecific and limited by systemic toxicities, while the current generation of CDK4/6 inhibitors have shown promise in the treatment of hormone receptor-positive breast cancer. Preclinical investigations of the three CDK4/6 inhibitors approved by the US Food and Drug Administration (palbociclib, ribociclib, and abemaciclib) lend further insight into their mechanism of action, which will hopefully inform the future use and refinement of these therapies. Finally, we summarize evidence for additional novel CDK4/6 inhibitors currently in development.     

Tca8113舌癌细胞转染骨形成蛋白-Ⅱ型突变受体前后细胞周期相关因子表达的定量分析

目的明确转染骨形成蛋白(BMP)-Ⅱ型突变受体对Tca8113舌癌细胞的作用,以进一步探讨BMPs对口腔上皮恶变的作用机制。方法检测转染BMP-Ⅱ型突变受体的Tca8113舌癌细胞(Tca8113ZR细胞)和Tca8113细胞的细胞周期相关因子Cyclind1、CDK-4、p27和p57的表达。结果转染了BMP-Ⅱ型突变受体后,肿瘤细胞的增殖能力显著减弱。结论BMPs信号在口腔舌癌细胞的恶性变化中起着重要的调控作用,BMPs信号的改变可能导致细胞恶性程度的改变。     

羽扇豆醇调控miR-100-5p对非小细胞肺癌NCI-H1299细胞生物学行为的影响

目的 探讨羽扇豆醇调控miR-100-5p对非小细胞肺癌（NSCLC）NCI-H1299细胞增殖、迁移和侵袭的影响。方法 将体外培养的NCI-H1299细胞分为正常对照（NC）组（未处理）、低剂量组（12.5μmol/L羽扇豆醇）、中剂量组（25μmol/L羽扇豆醇）、高剂量组（50μmol/L羽扇豆醇）、miR-NC组（转染miR-NC）、miR-100-5p组（转染miR-100-5p）、anti-miR-NC+高剂量组（转染anti-miR-NC后用50μmol/L羽扇豆醇处理）、anti-miR-100-5p+高剂量组（转染anti-miR-100-5p后用50μmol/L羽扇豆醇处理）。CCK-8和克隆形成实验检测NCI-H1299细胞增殖;Transwell法检测NCI-H1299细胞迁移和侵袭。荧光定量PCR(q PCR)检测miR-100-5p表达;Western blot检测细胞周期蛋白D1(CyclinD1)、基质金属蛋白酶（MMP）2和MMP9蛋白的表达。结果 与NC组比较,低、中、高剂量组NCI-H1299细胞活力、细胞克隆数、迁移数、侵袭数、CyclinD1、...     

血清肿瘤标志物联合检测在原发性肝癌诊断中的价值研究

目的:探讨细胞周期素A2(CCNA2)与甲胎蛋白(AFP)、癌胚抗原(CEA)、癌抗原199(CA199)及癌抗原724(CA724)的联合检测在原发性肝癌临床诊断中的价值,以期筛选出理想的肿瘤标志物组合,提高肝癌诊断的准确率。方法:选取2020年10月—2021年3月天津市第三中心医院收治的原发性肝癌患者68例为研究对象,作为原发性肝癌组;另选择同期收治的80例肝病患者作为肝良性疾病组,80例健康体检者作为健康对照组。采集各研究对象清晨空腹静脉血5 mL,采用addicare1100酶免仪利用酶联免疫吸附法(ELISA)检测血清CCNA2,采用罗氏e801全自动电化学发光仪及其配套试剂检测血清AFP、CEA、CA199和CA724。评估上述指标单项及联合检测在早期PLC诊断的应用价值。结果:健康对照组血清肿瘤标志物均显著低于肝良性疾病组与原发性肝癌组,差异有统计学意义(P＜0.05)。68例原发性肝癌患者中,对AFP、CEA、CA199、CA724和CCNA2等血清肿瘤标志物水平予以检测,联合检测的特异性和准确性均显著高于各指标的单项检测结果,差异有统计学意义(P＜0.05)。结论: CCNA2作为一种新型的肿瘤标志物,对肝癌的诊断具有一定的价值。CA199、CEA、AFP、CA724、CCNA2联合检测能显著提升原发性肝癌的诊断阳性率,对尽早诊断原发性肝癌具有重要意义。