Lisa R. Roberts

ABT-263: A Potent and Orally Bioavailable Bcl-2 Family Inhibitor

Overexpression of the prosurvival Bcl-2 family members (Bcl-2, Bcl-xL, and Mcl-1) is commonly associated with tumor maintenance, progression, and chemoresistance. We previously reported the discovery of ABT-737, a potent, small-molecule Bcl-2 family protein inhibitor. A major limitation of ABT-737 is that it is not orally bioavailable, which would limit chronic single agent therapy and flexibility to dose in combination regimens. Here we report the biological properties of ABT-263, a potent, orally bioavailable Bad-like BH3 mimetic (K(i)s of <1 nmol/L for Bcl-2, Bcl-xL, and Bcl-w). The oral bioavailability of ABT-263 in preclinical animal models is 20% to 50%, depending on formulation. ABT-263 disrupts Bcl-2/Bcl-xL interactions with pro-death proteins (e.g., Bim), leading to the initiation of apoptosis within 2 hours posttreatment. In human tumor cells, ABT-263 induces Bax translocation, cytochrome c release, and subsequent apoptosis. Oral administration of ABT-263 alone induces complete tumor regressions in xenograft models of small-cell lung cancer and acute lymphoblastic leukemia. In xenograft models of aggressive B-cell lymphoma and multiple myeloma where ABT-263 exhibits modest or no single agent activity, it significantly enhances the efficacy of clinically relevant therapeutic regimens. These data provide the rationale for clinical trials evaluating ABT-263 in small-cell lung cancer and B-cell malignancies. The oral efficacy of ABT-263 should provide dosing flexibility to maximize clinical utility both as a single agent and in combination regimens.

Acquired Resistance to Combination Treatment with Temozolomide and ABT-888 Is Mediated by Both Base Excision Repair and Homologous Recombination DNA Repair Pathways

Many established cancer therapies involve DNA-damaging chemotherapy or radiotherapy. Gain of DNA repair capacity of the tumor represents a common mechanism used by cancer cells to survive DNA-damaging therapy. Poly(ADP-ribose) polymerase-1 (PARP-1) is a nuclear enzyme that is activated by DNA damage and plays a critical role in base excision repair. Inhibition of PARP represents an attractive approach for the treatment of cancer. Previously, we have described the discovery and characterization of a potent PARP inhibitor, ABT-888. ABT-888 potentiates the activity of DNA-damaging agents such as temozolomide (TMZ) in a variety of preclinical models. We report here the generation of HCT116 cells resistant to treatment with TMZ and ABT-888 (HCT116R cells). HCT116R cells exhibit decreased H2AX phosphorylation in response to treatment with TMZ and ABT-888 relative to parental HCT116 cells. Microarray and Western blot studies indicate that HCT116R cells have decreased PARP-1 and elevated Rad51 expression levels. HCT116R cells are dependent on Rad51 for proliferation and survival, as shown by inhibition of proliferation and induction of apoptosis upon treatment with Rad51 small interfering RNA. In addition, HCT116R cells are more resistant to radiation than the parental HCT116 cells. Our study suggests that cancer cells upregulate the homologous recombination DNA repair pathway to compensate for the loss of base excision repair, which may account for the observed resistance to treatment with TMZ and ABT-888. (Mol Cancer Res 2009;7(10):1686–92)

Identification of methods for use of formalin-fixed, paraffin-embedded tissue samples in RNA expression profiling.

Formalin-fixed paraffin-embedded (FFPE) tissue samples are a potentially valuable resource of expression information for medical research, but are under-utilized due to degradation and modification of the RNA. Using a random primer-based RNA amplification strategy, we have evaluated multiple protocols for the extraction and isolation of RNA from FFPE samples. We found that the RecoverAll RNA isolation procedure with three or four slices (ten-microns in thickness), supplemented with additional DNAse, gave optimal results. RNA integrity as assessed by Agilent Bioanalyzer, and amplification of the 28S ribosomal RNA, were predictive for the number of genes detected on Affymetrix arrays. We obtained expression data for colon and lung tumor and normal FFPE samples and matched frozen samples and found a high correlation between frozen and matched FFPE samples (R(2) between 0.82 and 0.89), while the signature sets in tumor versus normal comparisons were also quite similar. QPCR confirmed all 16 of the differential expression results from the microarrays that we tested. Differentially expressed signature genes from tumor versus matched normal FFPE tissue from colon and lung were identified as cancer-related, with 95 colon tumor and 67 lung tumor genes identified, respectively.

Mindfulness-based Intervention for Perinatal Grief after Stillbirth in Rural India

We explored the concept of using a Mindfulness-based intervention to reduce perinatal grief among Indian women. Data were collected using mixed methods to explore concept acceptability, receptivity, modality, and feasibility of the intervention. The intervention was piloted and evaluated with measures of perinatal grief, psychosocial wellbeing, religious coping, perceived social provision of support, and mindfulness. The intervention was well received and effective in teaching skills to help women deal with high levels of grief and subsequent mental health challenges. To overcome attendance barriers modification is necessary. Partnership with a local nursing school is critical to enhance sustainability of the intervention.

Feasibility of Mindfulness-based Stress Reduction Intervention for Parents of Children with Developmental Delays

Mindfulness-based stress reduction (MBSR) interventions are popular as a treatment strategy for myriad diagnoses in various settings, and may be beneficial for parents of children with developmental delays (DD). However, prior research suggests extreme levels of stress and extraordinary demands on time among these parents, making the feasibility of effectively implementing MBSR with this population questionable. This study examined the feasibility of administering standard MBSR to a diverse community-based sample of parents of young children with DD. The potential impact of MBSR interventions includes improvement in parents’ mental health, and collateral benefits for the family environment, including improved child behavior. Nurses may have an integral role in interdisciplinary teams providing MBSR.

Grief and Women: Stillbirth in the Social Context of India.

INTRODUCTION Few in Western society would argue the potentially devastating impact of stillbirth related grief; but in many developing countries where stillbirth remains the highest in the world, perinatal grief is barely recognized as an issue. The purpose of this study was to explore how poor, rural central Indian women perceive and cope with stillbirths. METHODS Seventeen key informant interviews and two focus groups (N = 33) with local health care providers, family members, and women who experienced stillbirth were conducted over a 1-month period in 2011 and then systematically coded for emerging themes using grounded theory methods to explore how women experienced stillbirth. RESULTS Although usually never talked about and not recognized as an issue, perinatal grief emerged as a significant shared experience by all. The perceptions of stillbirth-related grief emerged in three major themes and bear evidence of gender and power issues and indicate that local social norms negatively factor heavily into their perinatal grief experiences. DISCUSSION The findings in this richly textured study add to the limited literature regarding rural, central Indian womens experiences with stillbirth and factors influencing their resulting perinatal grief. In light of the void of recognition of this phenomenon in Indian society, a better understanding of the context in which poor Indian women experience perinatal grief will be a first step toward developing much needed culturally rooted interventions to positively impact the womens abilities to better cope with stillbirth in the context of their realities.

Researching in Collectivist Cultures: Reflections and Recommendations.

Commonalities are presented from the experiences of U.S. nurse researchers who conducted studies in India, Jordan, Aotearoa/New Zealand, and Trinidad and Tobago. While planning research, it is important to engage collaborators who are members of the culture to be studied to understand what are culturally appropriate aims and methods. It is also vital to observe cultural etiquette, especially while gaining entrée and collecting data. Issues related to data collection include timing it around local holidays and events, and adapting individualist methods for obtaining consent and data to be more respectful for those in a collectivist culture. Care must be taken to give back, to sharing findings, and insure sustainability for future research in the host culture. Based on these and other reflections, recommendations are offered to support investigators planning research in a culture that is not their own.

JAK2V617F drives Mcl-1 expression and sensitizes hematologic cell lines to dual inhibition of JAK2 and Bcl-xL.

Constitutive activation of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) axis is fundamental to the molecular pathogenesis of a host of hematological disorders, including acute leukemias and myeloproliferative neoplasms (MPN). We demonstrate here that the major JAK2 mutation observed in these diseases (JAK2V617F) enforces Mcl-1 transcription via STAT3 signaling. Targeting this lesion with JAK inhibitor I (JAKi-I) attenuates STAT3 binding to the Mcl-1 promoter and suppresses Mcl-1 transcript and protein expression. The neutralization of Mcl-1 in JAK2V617F-harboring myelodyssplastic syndrome cell lines sensitizes them to apoptosis induced by the BH3-mimetic and Bcl-xL/Bcl-2 inhibitor, ABT-263. Moreover, simultaneously targeting JAK and Bcl-xL/-2 is synergistic in the presence of the JAK2V617F mutation. These findings suggest that JAK/Bcl-xL/-2 inhibitor combination therapy may have applicability in a range of hematological disorders characterized by activating JAK2 mutations.

Mental Health and Sociocultural Determinants in an Asian Indian Community.

In a US population of adult male and female Sikh immigrant participants (N = 350), we explored sociocultural factors related to depression, giving participants a choice between English or Punjabi surveys. Language preference pointed to a subgroup with higher levels of depression and lower satisfaction with life. Underreporting of depression suggests a general reluctance to discuss depression. While multiple sociocultural variables were associated with depression bivariably, multivariate analysis identified negative religious coping and anxiety as unique predictors of depression. Community interventions should tap into the protective close-knit social fabric of this community as an opportunity to change the stigma of mental health.

Addressing Stillbirth in India Must Include Men

ABSTRACT Background: Millennium Development Goal 4, to reduce child mortality, can only be achieved by reducing stillbirths globally. A confluence of medical and sociocultural factors contribute to the high stillbirth rates in India. The psychosocial aftermath of stillbirth is a well-documented public health problem, though less is known of the experience for men, particularly outside of the Western context. Therefore, mens perceptions and knowledge regarding reproductive health, as well as maternal-child health are important. Methods: Key informant interviews (n = 5) were analyzed and 28 structured interviews were conducted using a survey based on qualitative themes. Results: Qualitative themes included mens dual burden and right to medical and reproductive decision making power. Wives were discouraged from expressing grief and pushed to conceive again. If not successful, particularly if a son was not conceived, a second wife was considered a solution. Quantitative data revealed that men with a history of stillbirths had greater anxiety and depression, perceived less social support, but had more egalitarian views towards women than men without stillbirth experience. At the same time fathers of stillbirths were more likely to be emotionally or physically abusive. Predictors of mental health, attitudes towards women, and perceived support are discussed. Conclusions: Patriarchal societal values, son preference, deficient womens autonomy, and sex-selective abortion perpetuate the risk for future poor infant outcomes, including stillbirth, and compounds the already higher risk of stillbirth for males. Grief interventions should explore and take into account mens perceptions, attitudes, and behaviors towards reproductive decision making.