Local delivery of mRNA-encoded cytokines promotes antitumor immunity and tumor eradication across multiple preclinical tumor models.

Local immunotherapy ideally stimulates immune responses against tumors while avoiding toxicities associated with systemic administration. Current strategies for tumor-targeted, gene-based delivery, however, are limited by adverse effects such as off-targeting or antivector immunity. We investigated the intratumoral administration of saline-formulated messenger (m)RNA encoding four cytokines that were identified as mediators of tumor regression across different tumor models: interleukin-12 (IL-12) single chain, interferon-α (IFN-α), granulocyte-macrophage colony-stimulating factor, and IL-15 sushi. Effective antitumor activity of these cytokines relied on multiple immune cell populations and was accompanied by intratumoral IFN-γ induction, systemic antigen-specific T cell expansion, increased granzyme B+ T cell infiltration, and formation of immune memory. Antitumor activity extended beyond the treated lesions and inhibited growth of distant tumors and disseminated tumors. Combining the mRNAs with immunomodulatory antibodies enhanced antitumor responses in both injected and uninjected tumors, thus improving survival and tumor regression. Consequently, clinical testing of this cytokine-encoding mRNA mixture is now underway.

Screening with whole-body magnetic resonance imaging in pediatric subjects with Li-Fraumeni syndrome: A single institution pilot study.

BACKGROUND: Li-Fraumeni syndrome (LFS) is an autosomal dominant hereditary cancer syndrome associated with germline mutations in the TP53 gene and a high risk of childhood-onset malignancies. Cancer surveillance is challenging in pediatric mutation carriers given the anatomic spectrum of malignancies and young age of onset. Whole-body magnetic resonance imaging (WB-MRI) may provide an acceptable method for early cancer detection. PROCEDURE: We conducted a prospective feasibility pilot study of pediatric subjects (age < 18 years) with LFS to determine return rates for annual WB-MRI scan. Secondary objectives included characterization of incident cancers (and how they were detected). RESULTS: Forty-five WB-MRI scans in 20 subjects were performed over 5 years; two patients enrolled without subsequently undergoing scans. Eighty-nine percent of participants scanned (95% confidence interval: 67-99%) returned for second examinations. Fifty-five percent of participants required general anesthesia, which was well tolerated in all cases. Six patients required dedicated follow-up imaging. One participant required biopsy of a detected brain lesion; pathology demonstrated reactive gliosis. Another participant, with prior choroid plexus carcinoma, had a new brain lesion detected on clinical follow-up MRI not seen on WB-MRI 6 months prior. All other participants remain well (median: 3 years, range: 0.08-4 years). CONCLUSIONS: WB-MRI in pediatric subjects is a well-tolerated approach to cancer surveillance despite the need for general anesthesia in some patients. A large multicenter trial would determine true test characteristics and efficacy of this approach for early cancer detection in children at high cancer risk.

Germline TP53 Mutations in Patients With Early-Onset Colorectal Cancer in the Colon Cancer Family Registry.

IMPORTANCE: Li-Fraumeni syndrome, usually characterized by germline TP53 mutations, is associated with markedly elevated lifetime risks of multiple cancers, and has been linked to an increased risk of early-onset colorectal cancer. OBJECTIVE: To examine the frequency of germline TP53 alterations in patients with early-onset colorectal cancer. DESIGN, SETTING, AND PARTICIPANTS: This was a multicenter cross-sectional cohort study of individuals recruited to the Colon Cancer Family Registry (CCFR) from 1998 through 2007 (genetic testing data updated as of January 2015). Both population-based and clinic-based patients in the United States, Canada, Australia, and New Zealand were recruited to the CCFR. Demographic information, clinical history, and family history data were obtained at enrollment. Biospecimens were collected from consenting probands and families, including microsatellite instability and DNA mismatch repair immunohistochemistry results. A total of a 510 individuals diagnosed as having colorectal cancer at age 40 years or younger and lacking a known hereditary cancer syndrome were identified from the CCFR as being potentially eligible. Fifty-three participants were excluded owing to subsequent identification of germline mutations in DNA mismatch repair genes (n = 47) or biallelic MUTYH mutations (n = 6). INTERVENTIONS: Germline sequencing of the TP53 gene was performed. Identified TP53 alterations were assessed for pathogenicity using literature and international mutation database searches and in silico prediction models. MAIN OUTCOMES AND MEASURES: Frequency of nonsynonymous germline TP53 alterations. RESULTS: Among 457 eligible participants (314, population-based; 143, clinic-based; median age at diagnosis, 36 years [range, 15-40 years]), 6 (1.3%; 95% CI, 0.5%-2.8%) carried germline missense TP53 alterations, none of whom met clinical criteria for Li-Fraumeni syndrome. Four of the identified TP53 alterations have been previously described in the literature in probands with clinical features of Li-Fraumeni syndrome, and 2 were novel alterations. CONCLUSIONS AND RELEVANCE: In a large cohort of patients with early-onset colorectal cancer, germline TP53 mutations were detected at a frequency comparable with the published prevalence of germline APC mutations in colorectal cancer. With the increasing use of multigene next-generation sequencing panels in hereditary cancer risk assessment, clinicians will be faced with the challenge of interpreting the biologic and clinical significance of germline TP53 mutations in families whose phenotypes are atypical for Li-Fraumeni syndrome.

Prevalence of germline TP53 mutations in HER2+ breast cancer patients.

Breast cancer is the most frequent tumor in Li-Fraumeni syndrome (LFS), a rare inherited cancer syndrome associated with germline mutations in the TP53 gene. Recent data show that breast cancer in germline TP53 mutation carriers is commonly HER2+ (63-83 %). We assessed the prevalence of germline TP53 mutations in a cohort of women with HER2+ breast cancer diagnosed age ≤50 years. We identified blood specimens from 213 women with primary invasive HER2+ breast cancer age ≤50 years from a single center. Exon grouping analysis sequencing and multiplex ligation-dependent probe amplification techniques were used to screen for germline TP53 mutations. Among 213 women with HER2+ breast cancer age ≤50 years, 3 (ages at diagnosis 23, 32, 44 years) were found to carry a TP53 mutation (1.4 %, 95 % CI 0.3-4.1 %). ER/PR status was not uniform. Two TP53 carriers met Chompret criteria for LFS; none met classic LFS criteria. Although two-thirds of breast cancers in women with TP53 mutations are HER2+, we observed a low prevalence of germline TP53 mutations among unselected young women with HER2+ breast cancer. Given the potential clinical impact, consideration of germline TP53 testing should be given to young women with HER2+ breast cancer, especially if family cancer history is notable.

Breast cancer phenotype in women with TP53 germline mutations: a Li-Fraumeni syndrome consortium effort.

Breast cancer is the most common tumor in women with Li-Fraumeni Syndrome (LFS), an inherited cancer syndrome associated with germline mutations in the TP53 tumor suppressor gene. Their lifetime breast cancer risk is 49% by age 60. Breast cancers in TP53 mutation carriers recently have more often been reported to be hormone receptor and HER-2 positive by immunohistochemistry and FISH in small series. We seek to complement the existing small literature with this report of a histopathologic analysis of breast cancers from women with documented LFS. Unstained slides and paraffin-embedded tumor blocks from breast cancers from 39 germline TP53 mutation carriers were assembled from investigators in the LFS consortium. Central histology review was performed on 93% of the specimens by a single breast pathologist from a major university hospital. Histology, grade, and hormone receptor status were assessed by immunohistochemistry; HER-2 status was defined by immunohistochemistry and/or FISH. The 43 tumors from 39 women comprise 32 invasive ductal carcinomas and 11 ductal carcinomas in situ (DCIS). No other histologies were observed. The median age at diagnosis was 32 years (range 22-46). Of the invasive cancers, 84% were positive for ER and/or PR; and 81% were high grade. Sixty three percent of invasive and 73% of in situ carcinomas were positive for Her2/neu (IHC 3+ or FISH amplified). Of the invasive tumors, 53% were positive for both ER and HER2+; other ER/PR/HER2 combinations were observed. The DCIS were positive for ER and HER2 in 27% of the cases. This report of the phenotype of breast cancers from women with LFS nearly doubles the literature on this topic. Most DCIS and invasive ductal carcinomas in LFS are hormone receptor positive and/or HER-2 positive. These findings suggest that modern treatments may result in improved outcomes for women with LFS-associated breast cancer.

Gastric cancer in individuals with Li-Fraumeni syndrome.

PURPOSE: Li-Fraumeni syndrome is a rare hereditary cancer syndrome associated with germline mutations in the TP53 gene. Although sarcomas, brain tumors, leukemias, breast and adrenal cortical carcinomas are typically recognized as Li-Fraumeni syndrome-associated tumors, the occurrence of gastrointestinal neoplasms has not been fully evaluated. In this analysis, we investigated the frequency and characteristics of gastric cancer in Li-Fraumeni syndrome. METHODS: Pedigrees and medical records of 62 TP53 mutation-positive families were retrospectively reviewed from the Dana-Farber/National Cancer Institute Li-Fraumeni syndrome registry. We identified subjects with gastric cancer documented either by pathology report or death certificate and performed pathology review of the available specimens. RESULTS: Among 62 TP53 mutation-positive families, there were 429 cancer-affected individuals. Gastric cancer was the diagnosis in the lineages of 21 (4.9%) subjects from 14 families (22.6%). The mean and median ages at gastric cancer diagnosis were 43 and 36 years, respectively (range: 24-74 years), significantly younger compared with the median age at diagnosis in the general population based on Surveillance Epidemiology and End Results data (71 years). Five (8.1%) families reported two or more cases of gastric cancer, and six (9.7%) families had cases of both colorectal and gastric cancers. No association was seen between phenotype and type/location of the TP53 mutations. Pathology review of the available tumors revealed both intestinal and diffuse histologies. CONCLUSIONS: Early-onset gastric cancer seems to be a component of Li-Fraumeni syndrome, suggesting the need for early and regular endoscopic screening in individuals with germline TP53 mutations, particularly among those with a family history of gastric cancer.

Basal cytokeratin and epidermal growth factor receptor expression are not predictive of BRCA1 mutation status in women with triple-negative breast cancers.

BACKGROUND: Over 80% of breast cancers in women with germline BRCA1 mutations are estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2-negative ("triple negative") and most of these have a basal-like phenotype by expression profiling and immunophenotypic analysis. However, whether or not expression of biomarkers characteristic of basal-like breast cancers helps to define a subset of women with triple-negative breast cancers who are likely to harbor BRCA1 mutations is an unresolved issue. METHODS: We randomly identified 165 women from the Dana-Farber/Harvard Cancer Center SPORE annotated specimen bank with primary invasive, triple-negative breast cancers. Tissue microarrays were constructed by obtaining triplicate 0.6 mm cores from available paraffin blocks from 130 cases: only unstained slides were available for immunostaining from 35 cases. Slides cut from the tissue microarrays and the unstained slides were immunostained for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (to confirm triple-negative status) and for several markers that have been reported to be useful in defining the basal-like phenotype, including basal cytokeratins CK5/6, CK14, and CK17 and epidermal growth factor receptor (EGFR). Full sequencing analysis for BRCA1 germline mutations was performed on blood specimens from all cases. The final study population consisted of 144 cases in which (1) triple-negative status was confirmed; (2) there was sufficient material for analysis of basal cytokeratins and EGFR; and (3) germline BRCA1 mutation status was known. RESULTS: Among these triple-negative breast cancer cases, 97 (67%) expressed one or more basal cytokeratins and 102 (71%) showed EGFR expression. Basal cytokeratin expression was detected in 65% of the tumor from the 20 BRCA1 mutation carriers and in 68% of the cancers from women without mutations (P=NS). EGFR expression was identified in a similar proportion of tumors from women with and without BRCA1 mutations (75% vs. 72%, P=NS). CONCLUSIONS: Basal cytokeratin and EGFR expression are both highly prevalent among triple-negative breast cancers. The frequency of expression of basal cytokeratins and EGFR was similar in women with and without BRCA1 mutations. Therefore, although the expression of basal cytokeratins and/or EGFR can be used to identify triple-negative breast cancers that have a basal-like phenotype, expression of these markers alone is not sufficient to distinguish which women with triple-negative breast cancers are likely to harbor BRCA1 germline mutations.

F18-fluorodeoxyglucose-positron emission tomography/computed tomography screening in Li-Fraumeni syndrome.

CONTEXT: Individuals with Li-Fraumeni syndrome (LFS) have an inherited cancer predisposition to a diverse array of malignancies beginning early in life; survivors of one cancer have a markedly elevated risk of additional primary tumors. The underlying genetic defect in the majority of the families is a germline mutation in the TP53 tumor suppressor gene. The diversity of tumors and rarity of families have contributed to the difficulty in devising effective screening recommendations for members of LFS kindreds. OBJECTIVE: To gather preliminary data with which to evaluate F18-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) imaging as a potential surveillance modality to detect early malignancies in asymptomatic members of LFS kindreds. DESIGN, SETTING, AND PARTICIPANTS: Members of LFS families with documented germline TP53 mutations or obligate carrier status, no history of cancer within 5 years of enrollment, and no symptoms of cancer or ill-health were offered FDG-PET/CT scanning as a screening test in a comprehensive US cancer center from 2006 to 2007. Scans were initially reviewed clinically, then centrally reviewed by an expert radiologist. MAIN OUTCOME MEASURE: The primary outcome was the detection of new primary cancers using FDG-PET/CT scanning. RESULTS: Of 15 individuals, baseline FDG-PET/CT scan identified asymptomatic cancers in 3 (20%). Two individuals had papillary thyroid cancers (stage II and stage III) and one individual had stage II esophageal adenocarcinoma. CONCLUSIONS: These preliminary data provide the first evidence for a potential cancer surveillance strategy that may be worthy of further investigation for patients with LFS. Concerns about radiation exposure and other challenges inherent in screening high-risk patients will require further consideration.

Hereditary diffuse gastric cancer: association with lobular breast cancer.

Hereditary diffuse gastric cancer (HDGC) has been shown to be caused by germline mutations in the gene CDH1 located at 16q22.1, which encodes the cell-cell adhesion molecule, E-cadherin. Not only does loss of expression of E-cadherin account for the morphologic differences between intestinal and diffuse gastric cancer (DGC) variants, but it also appears to lead to distinct cellular features which appear to be common amongst related cancers that have been seen in the syndrome. As in most hereditary cancer syndromes, multiple organ sites may be commonly affected by cancer, in HDGC, lobular carcinoma of the breast (LBC) and possibly other organ sites have been shown to be associated with the familial cancer syndrome. Given the complexity of HDGC, not only with regard to the management of the DGC risk, but also with regard to the risk for other related cancers, such as LBC, a multi-disciplinary approach is needed for the management of individuals with known CDH1 mutations.

Combination therapy with interleukin-6 receptor superantagonist Sant7 and dexamethasone induces antitumor effects in a novel SCID-hu In vivo model of human multiple myeloma.

Interleukin-6 (IL-6) protects multiple myeloma cells against apoptosis induced by glucocorticoids. Here, we investigated whether inhibition of the IL-6 signaling pathway by the IL-6 receptor superantagonist Sant7 enhances the in vivo antitumor effects of dexamethasone on the IL-6-dependent multiple myeloma cell line INA-6. For this purpose, we used a novel murine model of human multiple myeloma in which IL-6-dependent INA-6 multiple myeloma cells were directly injected into human bone marrow implants in severe combined immunodeficient (SCID) mice (SCID-hu). The effect of in vivo drug treatments on multiple myeloma cell growth was monitored by serial determinations of serum levels of soluble IL-6 receptor (shuIL-6R), which is released by INA-6 cells and served as a marker of tumor growth. In SCID-hu mice engrafted with INA-6 cells, treatment with either Sant7 or dexamethasone alone did not induce significant reduction in serum shuIL-6R levels. In contrast, the combination of Sant7 with dexamethasone resulted in a synergistic reduction in serum shuIL-6R levels after 6 consecutive days of treatment. Gene expression profiling of INA-6 cells showed down-regulation of proliferation/maintenance and cell cycle control genes, as well as up-regulation of apoptotic genes in multiple myeloma cells triggered by Sant7 and dexamethasone combination. In vitro colony assays showed inhibition of myeloid and erythroid colonies from normal human CD34(+) progenitors in response to dexamethasone, whereas Sant7 neither inhibited colony growth nor potentiated the inhibitory effect of dexamethasone. Taken together, these results indicate that inhibition of IL-6 signaling by Sant7 significantly potentiates the therapeutic action of dexamethasone against multiple myeloma cells, providing the preclinical rationale for clinical trials of Sant7 in combination with dexamethasone to improve patient outcome in multiple myeloma.

Differential sensitivity of BRCA1-mutated HCC1937 human breast cancer cells to microtubule-interfering agents.

Germ-line mutations in the breast cancer susceptibility BRCA1 gene account for approximately half of hereditary breast cancer cases and most of breast/ovarian cancer cases. We speculated whether breast hereditary cancers might be differentially sensitive to antitumor agents such as the mitotic spindle poisons Vinca alcaloid vinorelbine (VNR) and the taxoid docetaxel (DOC), which are commonly used in the treatment of breast cancer. We investigated the sensitivity of the BRCA1-mutated HCC1937 (derived from a BRCA1 related hereditary tumor) and BRCA1 competent MCF-7 and MDA-MB468 sporadic breast cancer cell lines to these drugs. We found that HCC1937 cells were significantly more sensitive to VNR as compared to MCF-7 or MDA-MB468 cells. Instead, BRCA1-mutated breast cancer cells exposed to DOC showed similar sensitivity as compared to BRCA1-competent MCF-7 or were less sensitive than MDA-MB468. In order to assess the role of BRCA1 in this specific pattern of chemosensitivity, we transfected the BRCA1-mutated HCC1937 cells with a full-length BRCA1 cDNA and the stable clone (HCC1937/WTBRCA1) was exposed to both drugs. Full-length BRCA1 transfection led to a significant induction of resistance to VNR, whereas only a weak but not significant increase of sensitivity to DOC was detected. Moreover, VNR induced apoptotic cell death and cytoskeletal rearrangements in HCC1937 cells. We further investigated whether a defective targeting of mitotic spindle by the mutated BRCA1 gene product might be involved in the differential sensitivity to VNR. We demonstrated that mutated BRCA1 was indeed capable of co-localizing with alpha-tubulin in the mitotic spindle, suggesting therefore that different mechanisms should account for these effects. In conclusion, our data suggest that BRCA1-mutated tumors might be differentially sensitive to anti-microtubule agents, supporting the rationale for clinical trials to improve the outcome of hereditary breast cancer patients by tailored treatments.

New pharmacokinetic and pharmacodynamic tools for interferon-alpha (IFN-alpha) treatment of human cancer.

Interferon alpha (IFN-alpha) has been widely used in the treatment of human solid and haematologic malignancies. Although the antitumour activity of IFN-alpha is well recognised at present, no major advances have been achieved in the last few years. Recent findings have provided new information on the molecular mechanisms of the antitumour activity of the cytokine. In fact, IFN-alpha appears to block cell proliferation, at least in part, through the induction of apoptotic effects. This cytokine can also regulate the progression of tumour cells through the different phases of the cell cycle inducing an increase of the expression of the cyclin-dependent kinase inhibitors p21 and p27. However, it must be considered that IFN-alpha is a physiologic molecule with ubiquitously expressed receptors that is likely to activate survival mechanisms in the cell. We have recently identified an epidermal growth factor (EGF) Ras-dependent protective response to the apoptosis induced by IFN-alpha in epidermoid cancer cells. The identification of tissue- and/or tumour-specific survival pathways and their selective targeting might provide a new approach to improve the efficacy of IFN-alpha-based treatment of human cancer. Moreover, new pegylated species of IFN-alpha are now available with a more favourable pharmacokinetic profile. We will review these achievements, and we will specifically address the topic of IFN-alpha-based molecularly targeted combinatory antitumour approaches.