Synergistic anti-proliferative effects of mTOR and MEK inhibitors in high-grade chondrosarcoma cell line OUMS-27

Chondrosarcoma of the spine: a narrative review

Chondrosarcoma is an uncommon primary bone tumor with an estimated incidence of 0.5 per 100,000 patient-years. Primary chondrosarcoma of the mobile spine and sacrum cumulatively account for less than 20% of all cases, most .commonly causing patients to present with focal pain with or without radiculopathy, or myelopathy secondary to neural element compression. Because of the rarity, patients benefit from multidisciplinary care at academic tertiary-care centers. Current standard-of-care consists of en bloc surgical resection with negative margins; for high grade lesions adjuvant focused radiation with ≥60 gray equivalents is taking an increased role in improving local control. Prognosis is dictated by lesion grade at the time of resection. Several groups have put forth survival calculators and epidemiological evidence suggests prognosis is quite good for lesions receiving R0 resection. Future efforts will be focused on identifying potential chemotherapeutic adjuvants and refining radiation treatments as a means of improving local control.

A New Compound with Increased Antitumor Activity by Cotargeting MEK and Pim-1

Feedback circuits are one of the major causes underlying tumor resistance. Thus, compounds that target one oncogenic pathway with simultaneously blocking its compensatory pathway will be of great value for cancer treatment. Here, we develop a new MEK inhibitor designated as KZ-02 that exhibits unexpectedly higher cytotoxicity than its starting compound AZD6244, a well-known MEK inhibitor, in colorectal cancer (CRC). Subsequent kinase selectivity study identified Pim-1 as an additional cellular target for KZ-02. Further studies showed that AZD6244 and Pim-1 1 (a Pim-1 inhibitor) have a synergistic effect on CRC suppression. Mechanistic study revealed that MEK inhibition by AZD6244 leads to increased Pim-1 expression, which could be a general mechanism behind the compromised cell-killing activity of MEK inhibitors. KZ-02, despite increasing Pim-1 mRNA expression, simultaneously promotes Pim-1 proteasomal degradation. Therefore, we uncover a new MEK inhibitor KZ-02 with significantly enhanced antitumor activity by co-targeting MEK and Pim-1.

An update on current and future treatment options for chondrosarcoma

Introduction: Human chondrosarcomas (CS; a malignant cartilage-forming bone tumor) respond poorly to chemotherapy and radiation treatment, resulting in high morbidity and mortality rates. Expanded treatment options are urgently needed. Areas covered: This article updates our 2014 review, in which we evaluated the CS treatments available at that time and potential treatment options under investigation. Since then, advances in research findings, particularly from Chinese herbal medicines, may be bringing us closer to more effective therapies for CS. In particular, promising findings have been reported from research targeting platelet-derived growth factor receptor. Expert opinion: Few treatment options exist for CS; chemotherapy is not even an option for unresectable disease, in which 5-year survival rates are just 2%. New information about the multitude of genes and signaling pathways that encourage CS growth, invasion and metastasis are clarifying how certain signaling pathways and plant-derived active compounds, especially molecularly-targeted therapies that inhibit the PDGF receptor, interfering with these biological processes. This review summarizes discoveries from the last 5 years and discusses how these findings are fueling ongoing work into effectively dealing with the disease process and improving the treatment of CS.

Scapula chondrosarcoma: A case report

RATIONALE

Chondrosarcoma is a malignant mesenchymal tumor originating from cartilage. The pelvis, ribs, femur, and humerus are the most frequently affected sites, and scapula involvement is relatively rare. The aim of the present study was to report a case of chondrosarcoma in the scapula.

PATIENT CONCERNS

A 42-year-old woman presented with a 3-month history of a painful mass in the right scapula.

DIAGNOSES AND INTERVENTION

The patient underwent tumor resection. The post-operative pathological diagnosis was scapula chondrosarcoma.

OUTCOMES

Following resection, the patient continued to receive routine follow-up care. There was no recurrence or tumor metastasis at a follow-up of 5 years.

CONCLUSIONS

Surgery remains the primary therapy for chondrosarcoma. One of the greatest challenges in the management of chondrosarcoma is to accurately assess tumor grade before surgical intervention. Chemotherapy and radiotherapy have been applied without success. Chemo- and radioresistance have been examined beyond classic phenotypic properties to identify more efficient therapeutic strategies. Therefore, development of future novel therapies is contingent upon elucidating the molecular mechanisms of chondrosarcoma.

IL-10 Could Play a Role in the Interrelation between Diabetes Mellitus and Osteoarthritis

The association between osteoarthritis (OA), obesity and metabolic syndrome suggests an interrelation between OA and diabetes mellitus (DM). Little is known about the role of anti-inflammatory cytokine interleukin (IL)-10 in the interrelation between OA and DM. Hence, the effects of IL-10 under hyperglycemia (HG) and hyperinsulinemia (HI) in human articular chondrocytes (hAC) and chondrosarcoma cell line Okayama University Medical School (OUMS)-27 were examined. HAC and OUMS-27, cultured in normoglycemic (NG) and HG conditions were stimulated with insulin and/or IL-10. Cell survival, metabolic activity, proliferation and extracellular matrix (ECM) synthesis were immunocytochemically examined. No significant differences in vitality of hAC neither in pure NG (NG_w/o) nor HG (HG_w/o) conditions were found. Applying HI and/or IL-10 in both conditions reduced significantly the vitality of hAC but not of OUMS-27. HG impaired significantly hAC metabolism. When combined with HI + IL-10 or IL-10 alone it decreased also significantly hAC proliferation compared to NG_w/o. In OUMS-27 it induced only a trend of impaired proliferation compared to NG_w/o. hAC but not OUMS-27 reduced significantly their collagen type (col) I, SOX9 and proteoglycan (PG) synthesis in HG combined with HI +/− IL-10 compared to NG_w/o. IL-10 could not moderate HI and HG effects. In contrast to hAC OUMS-27 showed limited sensitivity as DM model.

MLN4924, a Protein Neddylation Inhibitor, Suppresses the Growth of Human Chondrosarcoma through Inhibiting Cell Proliferation and Inducing Endoplasmic Reticulum Stress-Related Apoptosis

Chondrosarcoma, a heterogeneous malignant bone tumor, commonly produces cartilage matrix, which generally has no response to conventional therapies. Studies have reported that MLN4924, a NEDD8-activating enzyme inhibitor, achieves antitumor effects against numerous malignancies. In this study, the suppressive effects of MLN4924 on human chondrosarcoma cell lines were investigated using in vitro and in vivo assays, which involved measuring cell viability, cytotoxicity, apoptosis, proliferation, cell cycles, molecule-associated cell cycles, apoptosis, endoplasmic reticulum (ER) stress, and tumor growth in a xenograft mouse model. Our results demonstrated that MLN4924 significantly suppressed cell viability, exhibited cytotoxicity, and stimulated apoptosis through the activation of caspase-3 and caspase-7 in chondrosarcoma cell lines. Furthermore, MLN4924 significantly inhibited cell proliferation by diminishing the phosphorylation of histone H3 to cause G2/M cell cycle arrest. In addition, MLN4924 activated ER stress–related apoptosis by upregulating the phosphorylation of c-Jun N-terminal kinase (JNK), enhancing the expression of GRP78 and CCAAT-enhancer-binding protein homologous protein (CHOP, an inducer of endoplasmic ER stress–related apoptosis) and activating the cleavage of caspase-4. Moreover, MLN4924 considerably inhibited the growth of chondrosarcoma tumors in a xenograft mouse model. Finally, MLN4924-mediated antichondrosarcoma properties can be accompanied by the stimulation of ER stress–related apoptosis, implying that targeting neddylation by MLN4924 is a novel therapeutic strategy for treating chondrosarcoma.