Biomechanical remodeling of stroma by cancer-associated fibroblasts (CAF) in early stages of cancer is critical for cancer progression, and mechanical cues such as extracellular matrix stiffness control cell differentiation and malignant progression. However, the mechanism by which CAF activation occurs in low stiffness stroma in early stages of cancer is unclear. Here, we investigated the molecular mechanism underlying CAF regulation by SPIN90 and microtubule acetylation under conditions of mechanically soft matrices corresponding to normal stromal rigidity. SPIN90 was downregulated in breast cancer stroma but not tumor, and this low stromal expression correlated with decreased survival in breast cancer patients. deficiency facilitated recruitment of mDia2 and APC complex to microtubules, resulting in increased microtubule acetylation. This increased acetylation promoted nuclear localization of YAP, which upregulated expression of myofibroblast marker genes on soft matrices. depletion enhanced tumor progression, and blockade of microtubule acetylation in CAF significantly inhibited tumor growth in mice. Together, our data demonstrate that loss of SPIN90-mediated microtubule acetylation is a key step in CAF activation in low stiffness stroma. Moreover, correlation among these factors in human breast cancer tissue supports the clinical relevance of SPIN90 and microtubule acetylation in tumor development. .

Microtubules are one of the major targets for anticancer drugs because of their role in cell proliferation and migration. However, as anticancer drugs targeting microtubules have side effects, including the death of normal cells, it is necessary to develop anticancer agents that can target microtubules by specifically acting on cancer cells only. In this study, we identified chemicals that can act as anticancer agents by specifically binding to acetylated microtubules, which are predominant in triple-negative breast cancer (TNBC). The chemical compounds disrupted acetylated microtubule lattices by interfering with microtubule access to alpha-tubulin acetyltransferase 1 (αTAT1), a major acetyltransferase of microtubules, resulting in the increased apoptotic cell death of MDA-MB-231 cells (a TNBC cell line) compared with other cells, such as MCF-10A and MCF-7, which lack microtubule acetylation. Moreover, mouse xenograft experiments showed that treatment with the chemical compounds markedly reduced tumor growth progression. Taken together, the newly identified chemical compounds can be selective for acetylated microtubules and act as potential therapeutic agents against microtubule acetylation enrichment in TNBC.

Cancer-associated fibroblasts (CAFs) in the tumor microenvironment play major roles in supporting cancer progression. A previous report showed that SPIN90 downregulation is correlated with CAF activation and that SPIN90-deficient CAFs promote breast cancer progression. However, the mechanisms that mediate cancer-stroma interaction and how such interactions regulate cancer progression are not well understood. Here, we show that extra domain A (EDA)-containing fibronectin (FN), FN(+)EDA, produced by mouse embryonic fibroblasts (MEFs) derived from Spin90knockout (KO) mice increases their own myofibroblast differentiation, which facilitates breast cancer progression. Increased FN(+)EDA in Spin90-KO MEFs promoted fibril formation in the extracellular matrix (ECM) and specifically interacted with integrin α4β1 as the mediating receptor. Moreover, FN(+)EDA expression by Spin90-KO MEFs increased proliferation, migration, and invasion of breast cancer cells. Irigenin, a specific inhibitor of the interaction between integrin α4β1 and FN(+) EDA, significantly blocked the effects of FN(+)EDA, such as fibril formation by Spin90-KO MEFs and proliferation, migration, and invasion of breast cancer cells. In orthotopic breast cancer mouse models, irigenin injection remarkably reduced tumor growth and lung metastases. It was supported by that FN(+)EDA in assembled fibrils was accumulated in cancer stroma of human breast cancer patients in which SPIN90 expression was downregulated. Our data suggest that SPIN90 downregulation increases FN(+)EDA and promotes ECM stiffening in breast cancer stroma through an assembly of long FN(+)EDA-rich fibrils; moreover, engagement of the Integrin α4β1 receptor facilitates breast cancer progression. Inhibitory effects of irigenin on tumor growth and metastasis suggest the potential of this agent as an anticancer therapeutic. K E Y W O R D S cancer-associated fibroblast, extracellular matrix, FN(+)EDA, SPIN90, tumor microenvironment Breast cancer tissues with adjacent normal epithelial tissues of Human patients were kindly supplied and analyzed by Chungbuk

Background: The incidence of precocious puberty has increased throughout the 20th century. The association between precocious puberty and endocrine disrupting chemicals including agricultural pesticides has been a subject of global study, but human data are lacking. Purpose: We investigated the relationship between agricultural pesticides and the development of precocious puberty.Methods: We enrolled 60 female subjects at Severance Children’s Hospital from December 2015 to January 2017. Of them, 30 were diagnosed with precocious puberty, while the other 30 prepubertal girls were enrolled as normal controls. We investigated their clinical characteristics and analyzed the urinary levels of 320 different agricultural pesticides.Results: Agricultural pesticide was detected in one of 30 patients with precocious puberty (3.3%) versus 2 of 30 girls in the normal control group (3.3% vs. 6.7%, <i>P</i>=0.554). Dinotefuran, a neonicotinoid-class insecticide, was detected in the samples of all 3 positive subjects.Conclusion: Our results showed no relationship between agricultural pesticides and the development of precocious puberty. Larger sample sizes and robustly controlled variables are necessary to further investigate this topic.

Cushing syndrome (CS) is a rare disease caused by hypercortisolemia. Although surgical treatment is the first-line treatment in CS, the appropriate medication for the patient’s condition should be selected when medical treatment is needed. Etomidate is an adrenal-blocking drug used to treat CS and the most suitable for severe hypercortisolemia and adrenocortical carcinoma (ACC), due to cardiovascular stability and an anti-tumorigenic effect. However, its use and safe recommended dosage in infants with CS is unreported. Here we describe the case of a 2-month-old girl treated with etomidate for CS caused by ACC. Even though radical mass excision was performed, severe hypercortisolemia persisted, resulting from metastatic lesions in the liver, and medical treatment was considered. The etomidate doses, no bolus dose and infusion rate of 0.03 mg/kg/hour, may be an appropriate dose for severe hypercortisolemia in infants. This case will help determine future treatment strategies for similar cases in infants.

Cancer-associated fibroblasts (CAFs) in the tumor microenvironment (TME) interact closely with cancer cells to promote tumor development. Downregulation of SPIN90 in CAFs has been reported to facilitate breast cancer progression, but the underlying mechanism has not been elucidated. Here, we demonstrate that miR-130b-3p directly downregulates SPIN90 in stromal fibroblasts, leading to their differentiation into CAFs. As the decrease of SPIN90 in CAFs was shown to be more prominent in estrogen receptor (ER)-positive breast tumors in this study, miR-130b-3p was selected by bioinformatics analysis of data from patients with ER-positive breast cancer. Ectopic expression of miR-130b-3p in fibroblasts accelerated their differentiation to CAFs that promote cancer cell motility; this was associated with SPIN90 downregulation. We also found that miR-130b-3p was generated in luminal A-type cancer cells and activated fibroblasts after being secreted via exosomes from cancer cells. Finally, miR-130b-3p increased in SPIN90-downregulated tumor stroma of luminal A breast cancer patients and MCF7 cell-xenograft model mice. Our data demonstrate that miR-130b-3p is a key modulator that downregulates SPIN90 in breast CAFs. The inverse correlation between miR-130b-3p and SPIN90 in tumor stroma suggests that the miR-130b-3p/SPIN90 axis is clinically significant for CAF activation during breast cancer progression.

Alterations in mechanical properties in the extracellular matrix are modulated by myofibroblasts and are required for progressive fibrotic diseases. Recently, we reported that fibroblasts depleted of SPIN90 showed enhanced differentiation into myofibroblasts via increased acetylation of microtubules in the soft matrix; the mechanisms of the underlying signaling network, however, remain unclear. In this study, we determine the effect of depletion of SPIN90 on FAK/ROCK signaling modules. Transcriptome analysis of Spin90 KO mouse embryonic fibroblasts (MEF) and fibroblasts activated by TGF‐β revealed that Postn is the most significantly upregulated gene. Knockdown of Postn by small interfering RNA suppressed cell adhesion and myofibroblastic differentiation and downregulated FAK activity in Spin90 KO MEF. Our results indicate that SPIN90 depletion activates FAK/ROCK signaling, induced by Postn expression, which is critical for myofibroblastic differentiation on soft matrices mimicking the mechanical environment of a normal tissue.

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