Gli2 Overexpression Alters the Differentiation Status of Dedifferentiated Liposarcoma Cells and Results in an Immunosuppressive Myeloid Phenotype in Orthotopic Tumors.

Sarcomas are a rare classification of tumor derived from tissues of mesenchymal origin including bone, fat, muscle, cartilage, and blood vessels. These tumors often grow rapidly and have limited treatment options with few significant therapeutic advances in recent years. Liposarcomas (LPSs), the most common type of malignant soft tissue sarcoma, are derived from mesenchymal progenitors that have undergone an adipogenic lineage commitment compared to their multipotent counterparts. Interestingly, the grade of differentiation within LPS can vary highly, and the differentiation status of these tumors can drastically affect prognosis and likelihood of metastasis, making tumor differentiation a potential mechanism to target in liposarcoma development. Here, we show that overexpression of the Hedgehog transcription factor Gli2 in dedifferentiated liposarcoma (DDLPS) cells represses adipogenic differentiation while simultaneously activating markers of osteoblast differentiation in vitro . In addition, we observed marked differences in cytokine expression and secretion, prompting us to perform orthotopic fat pad injections of control and Gli2 overexpressing DDLPS cells. Using flow cytometry, we observed distinct changes in fat pad macrophage populations, with a particular increase in M2-like macrophages. Taken together, we find that overexpression of Gli2 in DDLPS cells alters their differentiation capacity and interactions between tumor cells and macrophages, highlighting a novel role for this developmental transcription factor in liposarcoma pathogenesis.

Pharmacologic Hedgehog inhibition modulates the cytokine profile of osteolytic breast cancer cells.

The establishment and progression of bone metastatic breast cancer is supported by immunosuppressive myeloid populations that enable tumor growth by dampening the innate and adaptive immune response. Much work remains to understand how to target these tumor-myeloid interactions to improve treatment outcomes. Noncanonical Hedgehog signaling is an essential component of bone metastatic tumor progression, and prior literature suggests a potential role for Hedgehog signaling and its downstream effector Gli2 in modulating immune responses. In this work, we sought to identify if inhibition of noncanonical Hedgehog signaling alters the cytokine profile of osteolytic breast cancer cells and the subsequent communication between the tumor cells and myeloid cells. Examination of large patient databases revealed significant relationships between Gli2 expression and expression of markers of myeloid maturation and activation as well as cytokine expression. We found that treatment with HPI-1 reduced tumor cell expression of numerous cytokine genes, including CSF1, CSF2, and CSF3, as well as CCL2 and IL6. Secreted CSF-1 (M-CSF) was also reduced by treatment. Changes in tumor-secreted factors resulted in polarization of THP-1 monocytes toward a proinflammatory phenotype, characterized by increased CD14 and CD40 surface marker expression. We therefore propose M-CSF as a novel target of Hedgehog inhibition with potential future applications in altering the immune microenvironment in addition to its known roles in reducing tumor-induced bone disease.

Targeting hedgehog-driven mechanisms of drug-resistant cancers.

Due to the cellular plasticity that is inherent to cancer, the acquisition of resistance to therapy remains one of the biggest obstacles to patient care. In many patients, the surviving cancer cell subpopulation goes on to proliferate or metastasize, often as the result of dramatically altered cell signaling and transcriptional pathways. A notable example is the Hedgehog (Hh) signaling pathway, which is a driver of several cancer subtypes and aberrantly activated in a wide range of malignancies in response to therapy. This review will summarize the field's current understanding of the many roles played by Hh signaling in drug resistance and will include topics such as non-canonical activation of Gli proteins, amplification of genes which promote tolerance to chemotherapy, the use of hedgehog-targeted drugs and tool compounds, and remaining gaps in our knowledge of the transcriptional mechanisms at play.

Weight gain prevention among black women in the rural community health center setting: the Shape Program.

BACKGROUND: Nearly 60% of black women are obese. Despite their increased risk of obesity and associated chronic diseases, black women have been underrepresented in clinical trials of weight loss interventions, particularly those conducted in the primary care setting. Further, existing obesity treatments are less effective for this population. The promotion of weight maintenance can be achieved at lower treatment intensity than can weight loss and holds promise in reducing obesity-associated chronic disease risk. Weight gain prevention may also be more consistent with the obesity-related sociocultural perspectives of black women than are traditional weight loss approaches. METHODS/DESIGN: We conducted an 18-month randomized controlled trial (the Shape Program) of a weight gain prevention intervention for overweight black female patients in the primary care setting. Participants include 194 premenopausal black women aged 25 to 44 years with a BMI of 25-34.9 kg/m2. Participants were randomized either to usual care or to a 12-month intervention that consisted of: tailored obesogenic behavior change goals, self-monitoring via interactive voice response phone calls, tailored skills training materials, 12 counseling calls with a registered dietitian and a 12-month YMCA membership.Participants are followed over 18 months, with study visits at baseline, 6-, 12- and 18-months. Anthropometric data, blood pressure, fasting lipids, fasting glucose, and self-administered surveys are collected at each visit. Accelerometer data is collected at baseline and 12-months.At baseline, participants were an average of 35.4 years old with a mean body mass index of 30.2 kg/m2. Participants were mostly employed and low-income. Almost half of the sample reported a diagnosis of hypertension or prehypertension and 12% reported a diagnosis of diabetes or prediabetes. Almost one-third of participants smoked and over 20% scored above the clinical threshold for depression. DISCUSSION: The Shape Program utilizes an innovative intervention approach to lower the risk of obesity and obesity-associated chronic disease among black women in the primary care setting. The intervention was informed by behavior change theory and aims to prevent weight gain using inexpensive mobile technologies and existing health center resources. Baseline characteristics reflect a socioeconomically disadvantaged, high-risk population sample in need of evidence-based treatment strategies. TRIAL REGISTRATION: The trial is registered with clinicaltrials.gov NCT00938535.