ribociclib and Acute-Kidney-Injury

Among females, breast cancer is the most common type of cancer. Hormon receptor positive (HR+) subtype constitutes 75% of the diagnosed breast cancers. Combination of the cyclin D-cyclin-dependent kinase 4/6 (CDK4/6) inhibitor and endocrine therapy significantly improves overall survival and progression-free survival. Ribociclib is an oral CDK 4/6 inhibitor and some adverse effects are identified. According to MONALEESA 2-3-7 studies, no adverse effect (AE) were reported due to grade 3 or 4 acute kidney injury (AKI) that caused treatment discontinuation.. We report a ribociclib-induced grade 3 AKI in an elderly woman who was treated for metastatic breast cancer. During first cycle of therapy, she was admitted to the oncology clinic with diagnosis of AKI.. According to MONALEESA 2-3-7 studies; no AE were reported due to grade 3 or 4 AKI. Despite these studies, the FDA reported that 20% of patients with ribociclib + letrozole combination therapy may have any stage elevation of creatinine. Ribociclib induced creatinine elevations are generally mild (grade 1-2) and can be managed by dose reduction or close monitoring of creatinine levels. We report the first case of grade 3 AKI that caused treatment discontinuation following administration of ribociclib.

Topics: Acute Kidney Injury; Aged; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Humans; Letrozole; Neoplasm Recurrence, Local; Purines; Receptors, Estrogen

Aberrant cell cycle activation is a hallmark of carcinogenesis. Recently three cell cycle targeting cyclin-dependent kinase 4/6 (CDK4/6) inhibitors have been approved for the treatment of metastatic breast cancer. CDK4/6 inhibitors suppress proliferation through inhibition of CDK4/6-dependent retinoblastoma-1 (Rb1) phosphorylation and inactivation, a key regulatory step in G1-to-S-phase transition. Importantly, aberrant cell cycle activation is also linked with several non-oncological diseases including acute kidney injury (AKI). AKI is a common disorder caused by toxic, inflammatory, and ischemic damage to renal tubular epithelial cells (RTECs). Interestingly, AKI triggered by the anti-cancer drug cisplatin can be mitigated by ribociclib, a CDK4/6 inhibitor, through mechanisms that remain unclear. Employing in vivo cell cycle analysis and functional Rb1 knock-down, here, we have examined the cellular and pharmacological basis of the renal protective effects of ribociclib during cisplatin nephrotoxicity. Remarkably, siRNA-mediated Rb1 silencing or RTEC-specific Rb1 gene ablation did not alter the severity of cisplatin-associated AKI; however, it completely abrogated the protective effects conferred by ribociclib administration. Furthermore, we find that cisplatin treatment evokes CDK4/6 activation and Rb1 phosphorylation in the normally quiescent RTECs, however, this is not followed by S-phase entry likely due to DNA-damage induced G1 arrest. The cytoprotective effects of ribociclib are thus not a result of suppression of S-phase entry but are likely dependent on the maintenance of Rb1 in a hypo-phosphorylated and functionally active form under stress conditions. These findings delineate the role of Rb1 in AKI and illustrate the pharmacological basis of the renal protective effects of CDK4/6 inhibitors.

Topics: Acute Kidney Injury; Aminopyridines; Animals; Cell Cycle Checkpoints; Cells, Cultured; Cisplatin; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Cytoprotection; Disease Models, Animal; DNA Damage; Epithelial Cells; Gene Knockdown Techniques; Kidney Tubules; Male; Mice; Mice, Knockout; Phosphorylation; Protective Agents; Purines; Retinoblastoma Binding Proteins; Signal Transduction

To investigate the role of Ribociclib in sepsis induced-acute kidney injury (AKI) and its possible mechanisms.. (1) Twenty adult male C57BL/6 mice were divided into sham operation group (Sham group; only open the abdomen without ligating or perforating the cecum, administered with sodium lactate buffer 12 hours before the sham operation), Ribociclib control group (administered with 150 mg/kg Ribociclib), cecal ligation and puncture (CLP) group (sepsis model induced by CLP; lactate buffer was given by intragastric administration 12 hours before CLP), and Ribociclib pretreatment group (administered with 150 mg/kg Ribociclib 12 hours before CLP) according to random number table, with 5 mice in each group. Kidneys were harvested 12 hours after the operation. Pathological changes in kidney were observed by hematoxylin-eosin (HE) staining. Tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels in mice kidney homogenate were measured by enzyme linked immunosorbent assay (ELISA). Western Blot was used to detect the expression of cell cycle-related protein phosphorylate retinoblastoma protein (p-Rb), apoptosis-related protein Bcl-2 and Bax. (2) Mouse renal tubular epithelial (TCMK-1) cell line was used for in vitro experiment. The cells were divided into control group, Ribociclib group (treated with 5 μmol/L Ribociclib for 24 hours), lipopolysaccharide (LPS) group (treated with 200 mg/L LPS for 6 hours), Ribociclib+LPS group (replaced with the medium containing 5 μmol/L Ribociclib and 200 mg/L LPS for 6 hours after exposing with 5 μmol/L Ribociclib for 18 hours). Inflammatory cytokines in cell culture medium were detected by ELISA. The expression of p-Rb, Bcl-2 and Bax, autophagy-related proteins microtubule associated protein 1 light chain LC3b (LC3b II, LC3b I) and p62, phosphate protein kinase B (p-AKT), phosphorylated mammalian target of rapamycin (p-mTOR) were measured by Western Blot.. (1) Animal experiments showed that, compared with the Sham group, the kidney tissue of mice were significantly damaged, the levels of TNF-α and IL-6 were increased, the expressions of p-Rb and Bcl-2/Bax ratio were decreased in kidney tissue in CLP group; but there was no significant difference in indexes between Ribociclib control group and Sham group. Compared with the CLP group, kidney injury in mice pretreated with Ribociclib was significantly ameliorated, the pathological score was significantly decreased (1.48±0.16 vs. 2.68±0.16, P < 0.01), the levels of TNF-α and IL-6 in kidney homogenate were significantly decreased [TNF-α (ng/g): 340.55±34.96 vs. 745.08±58.86, IL-6 (mg/g): 17.33±1.01 vs. 114.20±20.49, both P < 0.01], the expression of p-Rb was furtherly decreased (p-Rb/β-tubulin: 0.14±0.01 vs. 0.73±0.06, P < 0.01), Bcl-2/Bax ratio was increased (0.89±0.06 vs. 0.62±0.10, P < 0.01). (2) In vitro experiments showed that, compared with the control group, the releases of TNF-α and IL-6 were increased, the expression of p-Rb was decreased, the ratios of Bcl-2/Bax and LC3b II/I were decreased, the expressions of p62, p-AKT and p-mTOR were increased in LPS group; the expression of p-Rb was decreased after Ribociclib treatment in TCMK-1 cells. Compared with the LPS group, TNF-α and IL-6 were decreased [TNF-α (ng/L): 2.73±0.23 vs. 4.96±0.10, IL-6 (ng/L): 36.05±5.83 vs. 53.78±24.08, both P < 0.01], the expression of p-Rb was furtherly decreased (p-Rb/β-tubulin: 0.25±0.05 vs. 0.65±0.05, P < 0.01), the ratios of Bcl-2/Bax and LC3b II/I were increased (Bcl-2/Bax: 1.01±0.07 vs. 0.73±0.05, LC3b II/I: 2.08±0.31 vs. 1.04±0.01, both P < 0.05), the expressions of p62, p-AKT and p-mTOR were decreased (p62/β-tubulin: 0.59±0.01 vs. 1.09±0.08, p-AKT/β-tubulin: 0.61±0.03 vs. 1.20±0.06, p-mTOR/β-tubulin: 0.50±0.05 vs. 1.15±0.08, all P < 0.01) in the Ribociclib+LPS group.. Ribociclib pretreatment ameliorated sepsis-induced AKI and AKT/mTOR pathway may be involved in the protective role of Ribociclib on kidney.

Topics: Acute Kidney Injury; Aminopyridines; Animals; Male; Mice; Mice, Inbred C57BL; Protective Agents; Purines; Sepsis; Tumor Necrosis Factor-alpha

Acute kidney injury (AKI) is a potentially fatal syndrome characterized by a rapid decline in kidney function caused by ischemic or toxic injury to renal tubular cells. The widely used chemotherapy drug cisplatin accumulates preferentially in the renal tubular cells and is a frequent cause of drug-induced AKI. During the development of AKI the quiescent tubular cells reenter the cell cycle. Strategies that block cell-cycle progression ameliorate kidney injury, possibly by averting cell division in the presence of extensive DNA damage. However, the early signaling events that lead to cell-cycle activation during AKI are not known. In the current study, using mouse models of cisplatin nephrotoxicity, we show that the G1/S-regulating cyclin-dependent kinase 4/6 (CDK4/6) pathway is activated in parallel with renal cell-cycle entry but before the development of AKI. Targeted inhibition of CDK4/6 pathway by small-molecule inhibitors palbociclib (PD-0332991) and ribociclib (LEE011) resulted in inhibition of cell-cycle progression, amelioration of kidney injury, and improved overall survival. Of additional significance, these compounds were found to be potent inhibitors of organic cation transporter 2 (OCT2), which contributes to the cellular accumulation of cisplatin and subsequent kidney injury. The unique cell-cycle and OCT2-targeting activities of palbociclib and LEE011, combined with their potential for clinical translation, support their further exploration as therapeutic candidates for prevention of AKI.

Topics: Acute Kidney Injury; Aminopyridines; Animals; Cell Cycle Checkpoints; Cisplatin; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Disease Models, Animal; Enzyme Activation; HEK293 Cells; HeLa Cells; Humans; Kidney Tubules; Mice; Organic Cation Transport Proteins; Organic Cation Transporter 2; Piperazines; Protective Agents; Purines; Pyridines; Small Molecule Libraries