Blocking miR-27a-3p sensitises Taxol resistant osteosarcoma cells through targeting Fbxw7

Deciphering chemoresistance in osteosarcoma: Unveiling regulatory mechanisms and function through the lens of noncoding RNA

Osteosarcoma (OS) is a primary malignant bone tumor and is prevalent in children, adolescents, and elderly individuals. It has the characteristics of high invasion and metastasis. Neoadjuvant chemotherapy combined with surgical resection is the most commonly used treatment for OS. However, the efficacy of OS is considerably diminished by chemotherapy resistance. In recent years, noncoding RNAs (ncRNAs), including microRNAs, long noncoding RNAs, and circular RNAs, are hot topics in the field of chemotherapy resistance research. Several studies have demonstrated that ncRNAs are substantially associated with chemoresistance in OS. Thus, the present study overviews the abnormally expressed ncRNAs in OS and the molecular mechanisms involved in chemoresistance, with an emphasis on their function in promoting or inhibiting chemoresistance. ncRNAs are expected to become potential therapeutic targets for overcoming drug resistance and predictive biomarkers in OS, which are of great significance for enhancing the therapeutic effect and improving the prognosis.

LINC00891 Attenuates the Proliferation and Metastasis of Osteosarcoma Cells via miR-27a-3p/TET1 Axis

Objective: There is currently no adequate treatment for osteosarcoma, a bone malignancy that poses a serious threat to adolescents and children. The dysregulation of long noncoding RNAs is associated with many cancers, including osteosarcoma. LINC00891 expression is aberrant in endometrial cancer, lung cancer, and thyroid cancer, and likely regulate the malignant behavior of cancer. However, the potential function and mechanisms of LINC00891 in osteosarcoma progression remain unclear. Materials and Methods: LINC00891, miR-27a-3p, and TET1 mRNA expression in osteosarcoma cells were analyzed using quantitative reverse transcription-polymerase chain reaction. CCK-8 and Transwell experiments were performed on osteosarcoma cells to investigate proliferation, migration, and invasion, respectively. Ten-eleven translocation 1 (TET1) protein was analyzed using western blotting. Luciferase experiment was performed to investigate the interactions between LINC00891 with miR-27a-3p, and miR-27a-3p with TET1. Results: LINC00891 expression was dramatically decreased in the five osteosarcoma cell lines examined, particularly in 143B and SaoS-2 cells. LINC00891 overexpression due to plasmid transfection sharply blocked the proliferation, migration, and invasion of osteosarcoma cells. Dual-luciferase reporter experiments found that LINC00891 sponges miR-27a-3p, and LINC00891 overexpression sharply decreases miR-27a-3p expression. Transfection with miR-27a-3p mimic accelerated the malignant behaviors in LINC00891 overexpressed-osteosarcoma cells. Moreover, TET1 was a novel targeted-gene of miR-27a-3p. TET1 protein was significantly impeded, whereas LINC00891 overexpression elevated TET1 mRNA and protein in osteosarcoma cells. MiR-27a-3p overexpression inhibited TET1 mRNA and protein in osteosarcoma cells. Conclusions: Our study verified that LINC00891 attenuates the proliferation and metastasis of osteosarcoma cells via the miR-27a-3p/TET1 axis. This study clarifies a new mechanism and therapeutic target for the development of osteosarcoma.

A spotlight on the interplay of signaling pathways and the role of miRNAs in osteosarcoma pathogenesis and therapeutic resistance

Osteosarcoma (OS) is one of the most common bone cancers that constantly affects children, teenagers, and young adults. Numerous epigenetic elements, such as miRNAs, have been shown to influence OS features like progression, initiation, angiogenesis, and treatment resistance. The expression of numerous genes implicated in OS pathogenesis might be regulated by miRNAs. This effect is ascribed to miRNAs' roles in the invasion, angiogenesis, metastasis, proliferation, cell cycle, and apoptosis. Important OS-related mechanistic networks like the WNT/b-catenin signaling, PTEN/AKT/mTOR axis, and KRAS mutations are also affected by miRNAs. In addition to pathophysiology, miRNAs may influence how the OS reacts to therapies like radiotherapy and chemotherapy. With a focus on how miRNAs affect OS signaling pathways, this review seeks to show how miRNAs and OS are related.

Effect of Paclitaxel Combined with Doxorubicin Hydrochloride Liposome Injection in the Treatment of Osteosarcoma and MRI Changes before and after Treatment

Objective

The aim of this study is to investigate the effect of paclitaxel combined with doxorubicin hydrochloride liposome injection (DHLI) in the treatment of osteosarcoma and the MRI changes before and after treatment.

Methods

A total of 108 osteosarcoma patients treated in our hospital (January 2020–April 2022) were selected to carry out a single-center retrospective study. Among them, 54 patients receiving the combination chemotherapy (MDT) with high-dose methotrexate, ifosfamide, cisplatin, and ADM were selected as the control group (COG), while 54 patients receiving MDT with high-dose methotrexate, ifosfamide, cisplatin, paclitaxel, and DHLI were chosen as the study group (STG). The COG and STG had the same dose intensity and chemotherapy cycles, and clinical and MRI evaluations were performed after treatment.

Results

The evaluation of postoperative clinical efficacy showed that the disease control rate (DCR) of the STG was markedly higher than that of the COG (P < 0.05). The incidence of cardiac toxicity was remarkably lower in the STG than that in the COG (P < 0.05), with no between-group differences in the incidence of fever, abnormal liver function, myelosuppression, stomatitis, and alopecia (P > 0.05). Obvious differences were found in the semiquantitative parameters of MRI in the STG before and after chemotherapy (P < 0.05) and were also found in the SI_max, TTP, SEE, PPE, WOR, and R values in the COG before and after chemotherapy (P < 0.05). After chemotherapy, statistical differences were observed in the semiquantitative parameters of MRI between the two groups, with lower parameters such as Slope, SI_max, SEE, and R values and higher parameters such as TTP, PPE, and WOR values in the STG than those in the COG (P < 0.05).

Conclusion

Paclitaxel combined with DHLI has definite efficacy in osteosarcoma chemotherapy, which is conducive to narrowing the lesion, controlling the disease, and reducing the occurrence of cardiac-related risk events. In addition, the semiquantitative parameters of dynamic contrast-enhanced MRI (DCE-MRI) have a high predictive value for the efficacy of chemotherapy, which can reflect the degree of tumor necrosis and contribute to a timely and objective assessment of the efficacy of osteosarcoma chemotherapy.

Recent Insight on Regulations of FBXW7 and Its Role in Immunotherapy

SCF^FBXW7 E3 ubiquitin ligase complex is a crucial enzyme of the ubiquitin proteasome system that participates in variant activities of cell process, and its component FBXW7 (F-box and WD repeat domain–containing 7) is responsible for recognizing and binding to substrates. The expression of FBXW7 is controlled by multiple pathways at different levels. FBXW7 facilitates the maturity and function maintenance of immune cells via functioning as a mediator of ubiquitination-dependent degradation of substrate proteins. FBXW7 deficiency or mutation results in the growth disturbance and dysfunction of immune cell, leads to the resistance against immunotherapy, and participates in multiple illnesses. It is likely that FBXW7 coordinating with its regulators and substrates could offer potential targets to improve the sensitivity and effects of immunotherapy. Here, we review the mechanisms of the regulation on FBXW7 and its tumor suppression role in immune filed among various diseases (mostly cancers) to explore novel immune targets and treatments.

The molecular mechanism of circRHOBTB3 inhibits the proliferation and invasion of epithelial ovarian cancer by serving as the ceRNA of miR-23a-3p

Rising evidences bespeak that circular RNAs are indispensable in regulating cellular biological behaviors and engaging in diseases' occurrence. CircRHOBTB3 has been reported to participate intimately in the progression of some cancers. Nevertheless, the mechanism by which circRHOBTB3 regulates tumorigenesis in epithelial ovarian cancer (EOC) remains ill-defined. The present study determined the expression pattern and bio-effects of circRHOBTB3 in EOC. Furthermore, it revealed that circRHOBTB3 could serve as the ceRNA of miR‑23a-3p to facilitate PTEN expression, suppress proliferation, G1/S transition, invasion, and promote apoptosis in EOC. Summarily, our findings provided a primary research foundation that circRHOBTB3 might be typified as a neoteric biomarker and a promising target of EOC, which is essential for improving the early diagnosis and precision treatment, so as to cut down EOC's mortality finally.