CD133-Dependent Activation of Phosphoinositide 3-Kinase /AKT/Mammalian Target of Rapamycin Signaling in Melanoma Progression and Drug Resistance

Melanoma frequently harbors genetic alterations in key molecules leading to the aberrant activation of PI3K and its downstream pathways. Although the role of PI3K/AKT/mTOR in melanoma progression and drug resistance is well documented, targeting the PI3K/AKT/mTOR pathway showed less efficiency in clinical trials than might have been expected, since the suppression of the PI3K/mTOR signaling pathway-induced feedback loops is mostly associated with the activation of compensatory pathways such as MAPK/MEK/ERK. Consequently, the development of intrinsic and acquired resistance can occur. As a solid tumor, melanoma is notorious for its heterogeneity. This can be expressed in the form of genetically divergent subpopulations including a small fraction of cancer stem-like cells (CSCs) and non-cancer stem cells (non-CSCs) that make the most of the tumor mass. Like other CSCs, melanoma stem-like cells (MSCs) are characterized by their unique cell surface proteins/stemness markers and aberrant signaling pathways. In addition to its function as a robust marker for stemness properties, CD133 is crucial for the maintenance of stemness properties and drug resistance. Herein, the role of CD133-dependent activation of PI3K/mTOR in the regulation of melanoma progression, drug resistance, and recurrence is reviewed.

Mechanisms of Melanoma Progression and Treatment Resistance: Role of Cancer Stem-like Cells

Melanoma is the third most common type of skin cancer, characterized by its heterogeneity and propensity to metastasize to distant organs. Melanoma is a heterogeneous tumor, composed of genetically divergent subpopulations, including a small fraction of melanoma-initiating cancer stem-like cells (CSCs) and many non-cancer stem cells (non-CSCs). CSCs are characterized by their unique surface proteins associated with aberrant signaling pathways with a causal or consequential relationship with tumor progression, drug resistance, and recurrence. Melanomas also harbor significant alterations in functional genes (BRAF, CDKN2A, NRAS, TP53, and NF1). Of these, the most common are the BRAF and NRAS oncogenes, with 50% of melanomas demonstrating the BRAF mutation (BRAFV600E). While the successful targeting of BRAFV600E does improve overall survival, the long-term efficacy of available therapeutic options is limited due to adverse side effects and reduced clinical efficacy. Additionally, drug resistance develops rapidly via mechanisms involving fast feedback re-activation of MAPK signaling pathways. This article updates information relevant to the mechanisms of melanoma progression and resistance and particularly the mechanistic role of CSCs in melanoma progression, drug resistance, and recurrence.

QOL-01. Inflammatory biomarkers and psychological sequela in pediatric brain tumor survivors

BACKGROUND AND AIMS: Pediatric brain tumors are the second most common type of pediatric cancer, and these patients face the worst health related quality of life (HRQOL) outcomes. Adult studies show increased inflammation association with lower HRQOL in adult brain tumor survivors. This relationship has not been explored in pediatric brain tumor survivors (PBTS). We conducted a case-control study to explore the relationship between inflammatory biomarkers and psychological sequela (i.e., sleep disturbance, fatigue, pain, negative affect) in PBTS. METHODS: Survivors aged 7-14 years with a primary brain tumor diagnosis were recruited from UMMC (N=29) and UAB (N=4) between 2016-2019. A control group (N=12) was recruited from UMMC well-child appointments. Parents and children completed self-reported surveys of pain, sleep, fatigue, and mood. The primary aims were to: (1) examine levels of C-reactive protein (CRP) inflammation in PBTS compared to controls (2) examine if higher CRP and SOX2 (from tumor tissue) were associated with psychological sequela. Independent samples T-Tests and spearman correlations evaluated aims. RESULTS: The final sample included 33 PBTS: median age=12.42 years; sex=51.5% female; race=63.6% Caucasian, 33.3% African American; pathologic diagnoses=67% astrocytoma/glioma, 11% medulloblastoma, 6% ependymoma, 12% other. Twelve controls had a median age=11.98 years; sex=41.7% female; race=16.7% Caucasian, 83.8% African American. There were marginal elevations in CRP for PBTS (44%, n=13) compared to controls (13%, n=1) (p=0.06). In PBTS, higher CRP levels were associated with greater parent-reported fatigue (p=0.035), sleep-wake disorders (p=0.017), excessive somnolence (p=0.042) and longer pain duration (p=0.037). From 13 tumor samples, positive SOX2 (69% of samples) was associated with increased parent-reported sleep-wake disorders (p=0.016), excessive somnolence (p=0.036), and both child and parent-reported sleep disturbance (child: p=0.014; parent: p=0.034). CONCLUSIONS: Elevated inflammation in PBTS, up to 9 years post-treatment, is consistently associated with increased sleep disturbance and fatigue. These relationships warrant further investigation in PBTS.

Surgical management of giant acne keloidalis nuchae lesions

Acne keloidalis nuchae (AKN) is a progressive inflammatory condition that affects posterior neck and occiput. Treatment options include antibiotics, steroids, lasers, radiotherapy and surgery.

We present three patients with advanced ‘tumor-stage’ AKN that underwent radical local excision followed by either immediate or delayed skin resurfacing, and briefly review existing literature.

Single-Institution Experience of Synovial Sarcoma

OBJECTIVES

The purpose of this study was to investigate the patient population and outcomes of synovial sarcoma at a single institution.

METHODS

A retrospective review of the medical records of 28 patients with synovial sarcoma diagnosed from 1992 to 2017 was performed. Demographics, staging, disease location, treatment, and response to treatment were reviewed.

RESULTS

Individuals with larger tumors at the time of presentation had an increased risk of death. An additional factor associated with poor prognosis in synovial sarcoma was increasing patient age. The patient population had a higher rate of nonextremity disease and lower overall survival when compared with national averages.

CONCLUSIONS

Nonextremity disease and large size of tumor at presentation may have contributed to the disparity in institutional outcomes from the national averages. The advanced presentation of synovial sarcoma remains a significant challenge in improving patient survival.

Malignant peripheral nerve sheath tumor of nasal cavity and paranasal sinus with 13 years of follow-up-A case report and review of literature

Although extremely rare, sarcomas including malignant peripheral nerve sheath tumors should be considered in the differential diagnosis of sino-nasal tract lesions. Long-term cure is possible through definitive operative management followed by adjuvant therapy.

Chondroblastoma-like Osteosarcoma

Context.—

Chondroblastoma-like osteosarcoma is an exceedingly rare variant of osteosarcoma, with 22 cases reported in the English-language literature. The tumor is slightly more common in males, with a broad age range (from childhood to elderly). The most commonly involved bones are the metatarsus and tibia, followed by the femur. Most tumors have malignant or worrisome radiographic findings. Prognosis is variable, depending on the presence or absence of lung metastases, local recurrence, and probably tumor location. Histologically, chondroblastoma-like osteosarcoma is characterized by monotonous, minimally to moderately atypical rounded cells with ovoid nuclei resembling chondroblastoma, and abnormal osteoid deposition with destruction of the bone.

Objective.—

To review the clinical, radiographic, and histopathologic features of chondroblastoma-like osteosarcoma.

Data Sources.—

PubMed-published chondroblastoma-like osteosarcoma cases in the English-language literature.

Conclusions.—

Although exceedingly rare, chondroblastoma-like osteosarcoma should be considered in the differential diagnosis of chondroblastoma, especially in the presence of radiologic findings suggestive of an aggressive lesion.

Cancer stem cell as therapeutic target for melanoma treatment

Human malignant melanoma is a highly aggressive skin tumor that is characterized by its extraordinary heterogeneity, propensity for dissemination to distant organs and resistance to cytotoxic agents. Although chemo- and immune-based therapies have been evaluated in clinical trials, most of these therapeutics do not show significant benefit for patients with advanced disease. Treatment failure in melanoma patients is attributed mainly to the development of tumor heterogeneity resulting from the formation of genetically divergent subpopulations. These subpopulations are composed of cancer stem-like cells (CSCs) as a small fraction and non-cancer stem cells that form the majority of the tumor mass. In recent years, CSCs gained more attention and suggested as valuable experimental model system for tumor study. In melanoma, intratumoral heterogeneity, progression and drug resistance result from the unique characteristics of melanoma stem cells (MSCs). These MSCs are characterized by their distinct protein signature and tumor growth-driving pathways, whose activation is mediated by driver mutation-dependent signal. The molecular features of MSCs are either in a causal or consequential relationship to melanoma progression, drug resistance and relapse. Here, we review the current scientific evidence that supports CSC hypothesis and the validity of MSCs-dependent pathways and their key molecules as potential therapeutic target for melanoma treatment.