Citations

Background There is no effective systemic therapy for metastatic adrenal cortical carcinoma (ACC) after failure of platinum-based chemotherapy. The efficacies of single-agent oral multikinase inhibitors (MKIs) or salvage immune checkpoint inhibitors (CPIs) have been very limited. It is unknown whether combining CPIs, such as pembrolizumab (PEM), with other therapies, such as MKIs, could yield higher response rates in ACC, yet this combination has shown promise in other cancers. Herein, we describe the first case series using PEM in combination with the MKI lenvatinib (LEN) in patients with progressive, metastatic ACC. Methods A retrospective case series describing the use of LEN/PEM as salvage therapy in patients with progressive/metastatic ACC. Results Eight patients were treated with the LEN/PEM combination therapy. Half were female, and the median age at time of diagnosis was 38 years (range 21–49). Three (37.5%) patients had hormonally active ACC. The median number of prior lines of systemic therapy was 4 (range 2–9). Six (75%) patients had had disease progression on prior CPIs and five (62.5%) patients had progressed on prior MKI therapy. The median progression-free survival was 5.5 months (95% CI 1.8–not reached) and median duration of therapy was 8.5 months (range 2–22). Two (25%) patients had a partial response, one (12.5%) patient had stable disease, and five (62.5%) patients had progressive disease. None of the eight patients stopped therapy because of adverse events. Conclusions In our small cohort of heavily pretreated patients with ACC, the combination of LEN/PEM was associated with objective responses in a subset of patients without significant toxicity. This combination should be formally investigated in phase II clinical trial with robust correlative studies to identify predictors for response.

ABSTRACTMutations in leucine‐rich repeat kinase 2 (LRRK2) are found in a significant proportion of late‐onset Parkinson's disease (PD) patients. Elucidating the neuroanatomical localization of LRRK2 will further define LRRK2 function and the molecular basis of PD. Here, we utilize recently characterized monoclonal antibodies to evaluate LRRK2 expression in rodent brain regions relevant to PD. In both mice and rats, LRRK2 is highly expressed in the cortex and striatum, particularly in pyramidal neurons of layer V and in medium spiny neurons within striosomes. Overall, rats have a more restricted distribution of LRRK2 compared with mice. Mice, but not rats, show high levels of LRRK2 expression in the substantia nigra pars compacta. Expression of the pathogenic LRRK2‐G2019S protein from mouse bacterial artificial chromosome (BAC) constructs closely mimics endogenous LRRK2 distribution in the mouse brain. However, LRRK2‐G2019S expression derived from human BAC constructs causes LRRK2 to be expressed in additional neuron subtypes in the rat such as striatal cholinergic interneurons and the substantia nigra pars compacta. The distribution of LRRK2 from human BAC constructs more closely resembles descriptions of LRRK2 in humans and nonhuman primates. Computational analyses of DNA regulatory elements in LRRK2 show a primate‐specific promoter sequence that does not exist in lower mammalian species. These noncoding regions may be involved in directing neuronal expression patterns. Together, these studies will aid in understanding the normal function of LRRK2 in the brain and will assist in model selection for future studies. J. Comp. Neurol. 522:2465–2480, 2014. © 2014 Wiley Periodicals, Inc.

ABSTRACTMutations in leucine‐rich repeat kinase 2 (LRRK2) are found in a significant proportion of late‐onset Parkinson's disease (PD) patients. Elucidating the neuroanatomical localization of LRRK2 will further define LRRK2 function and the molecular basis of PD. Here, we utilize recently characterized monoclonal antibodies to evaluate LRRK2 expression in rodent brain regions relevant to PD. In both mice and rats, LRRK2 is highly expressed in the cortex and striatum, particularly in pyramidal neurons of layer V and in medium spiny neurons within striosomes. Overall, rats have a more restricted distribution of LRRK2 compared with mice. Mice, but not rats, show high levels of LRRK2 expression in the substantia nigra pars compacta. Expression of the pathogenic LRRK2‐G2019S protein from mouse bacterial artificial chromosome (BAC) constructs closely mimics endogenous LRRK2 distribution in the mouse brain. However, LRRK2‐G2019S expression derived from human BAC constructs causes LRRK2 to be expressed in additional neuron subtypes in the rat such as striatal cholinergic interneurons and the substantia nigra pars compacta. The distribution of LRRK2 from human BAC constructs more closely resembles descriptions of LRRK2 in humans and nonhuman primates. Computational analyses of DNA regulatory elements in LRRK2 show a primate‐specific promoter sequence that does not exist in lower mammalian species. These noncoding regions may be involved in directing neuronal expression patterns. Together, these studies will aid in understanding the normal function of LRRK2 in the brain and will assist in model selection for future studies. J. Comp. Neurol. 522:2465–2480, 2014. © 2014 Wiley Periodicals, Inc.