NOTCH1 and PIK3CA mutation are related to HPV-associated vulvar squamous cell carcinoma

Quitting Your Day Job in Response to Stress: Cell Survival and Cell Death Require Secondary Cytoplasmic Roles of Cyclin C and Med13

Following unfavorable environmental cues, cells reprogram pathways that govern transcription, translation, and protein degradation systems. This reprogramming is essential to restore homeostasis or commit to cell death. This review focuses on the secondary roles of two nuclear transcriptional regulators, cyclin C and Med13, which play key roles in this decision process. Both proteins are members of the Mediator kinase module (MKM) of the Mediator complex, which, under normal physiological conditions, positively and negatively regulates a subset of stress response genes. However, cyclin C and Med13 translocate to the cytoplasm following cell death or cell survival cues, interacting with a host of cell death and cell survival proteins, respectively. In the cytoplasm, cyclin C is required for stress-induced mitochondrial hyperfission and promotes regulated cell death pathways. Cytoplasmic Med13 stimulates the stress-induced assembly of processing bodies (P-bodies) and is required for the autophagic degradation of a subset of P-body assembly factors by cargo hitchhiking autophagy. This review focuses on these secondary, a.k.a. "night jobs" of cyclin C and Med13, outlining the importance of these secondary functions in maintaining cellular homeostasis following stress.

Molecular characterization of metastatic penile squamous cell carcinoma in developing countries and its impact on clinical outcomes: LACOG 2018 translational study

BACKGROUND

Penile squamous cell carcinoma (PSCC) is a rare malignancy. However, in developing countries the incidence rate is higher. The understanding of molecular alterations is essential for evaluating possible targets for more effective systemic therapies.

METHODS

We retrospectively collected clinical data of metastatic PSCC (mPSCC) patients who had received at least one prior systemic treatment from 3 Brazilian hospitals. Tumor samples were evaluated using the next-generation sequencing (NGS) Foundation One DX and immunohistochemistry (IHC). The objective was to identify and describe somatic genomic alterations known to be functional or pathogenic and their association with survival outcomes.

RESULTS

Twenty-three patients were identified, 22 and 18 patients had tumor samples analyzed by IHC and NGS, respectively. PD-L1 expression (CPS ≥ 1%) was positive in 14 patients (63.6%). Regarding the genomic alterations, 16 patients (88.9%) had some clinically relevant genomic alterations. TP53, TERT, CDKN2A, PIK3CA, NOTCH1, and CDKN2B loss were identified in 66.7%, 50%, 50%, 33.3%, 27.8%, and 22.2% of the patients, respectively. No MSI or TMB high (≥10 mutations/MB) cases were identified. NOTCH1 mutation was identified only in HPV-negative patients and it was associated with worse OS (yes: 5.5 vs no: 12.8 months, P = .049) and progression-free survival (yes: 5.5 vs no: 11.7 months, P = .032).

CONCLUSION

This study demonstrated that molecular alterations in mPSCC from developing countries are similar to those from developed countries. Predictive biomarkers for immunotherapy response such as TMB high or MSI were not identified. Specific gene mutations may identify patients with worse prognoses and open new avenues for therapeutic development.

Role of Immunohistochemical Analysis of p16 and p53 in Vulvar Carcinoma

Tumor human papillomavirus (HPV) status is an important prognostic factor in vulvar cancer as indicated in the latest WHO classification of female genital tract tumors. Immunohistochemical detection of p16 is well established as a surrogate biomarker for tumor HPV association, including squamous cell carcinomas of the vulva. HPV-independent vulvar carcinomas are heterogeneous with 2 subcategories according to the TP53 mutation status. Therefore, the simultaneous use of p53 and p16 immunohistochemistry is recommended for accurate subclassification of vulvar squamous cell carcinomas. However, the role of molecular analytical tools, in particular RNA ISH and TP53 sequencing, is not so clear. This study aimed to investigate the performance of p53 and p16 immunohistochemistry for the diagnosis of vulvar carcinomas in comparison to TP53 mutation analysis and HPV RNA ISH. We analyzed 48 vulvar carcinomas in a tissue microarray format. Sensitivity and specificity for both methods, p16 (100% and 96%) and p53 (95% and 90%) immunohistochemistry for detection of HPV association as well as for TP53 mutations was high. Combining p16 and p53 immunohistochemistry we correctly classified all carcinomas in our series according to current WHO criteria. The sensitivity of HPV RNA ISH for the detection of HPV association was lower compared to p16 immunohistochemistry. Rare HPV-associated cases with TP53 mutation and HPV-independent tumors with p16 overexpression are discussed. In summary, the combined use of p16 and p53 immunohistochemistry for subclassification of vulvar carcinomas is justified in daily practice. Molecular tests should be restricted to rare cases with ambiguous clinicopathologic or immunohistochemical features.

Understanding PI3K/Akt/mTOR signaling in squamous cell carcinoma: mutated PIK3CA as an example

Compared with those in adenocarcinoma, PIK3CA mutations are more common in squamous cell carcinoma (SCC), which arises from stratified squamous epithelia that are usually exposed to adverse environmental factors. Although hotspot mutations in exons 9 and 20 of PIK3CA, including E542K, E545K, H1047L and H1047R, are frequently encountered in the clinic, their clinicopathological meaning remains to be determined in the context of SCC. Considering that few reviews on PIK3CA mutations in SCC are available in the literature, we undertook this review to shed light on the clinical significance of PIK3CA mutations, mainly regarding the implications and ramifications of PIK3CA mutations in malignant cell behavior, prognosis, relapse or recurrence and chemo- or radioresistance of SCC. It should be noted that only those studies regarding SCC in which PIK3CA was mutated were cherry-picked, which fell within the scope of this review. However, the role of mutated PIK3CA in adenocarcinoma has not been discussed. In addition, mutations occurring in other main members of the PI3K-AKT-mTOR signaling pathway other than PIK3CA were also excluded.