Abstract 6368: Discovery of potent, orally bioavailable, SOS1 inhibitors for KRAS-driven tumors

KRAS is an oncogene implicated in a wide variety of tumors (~21% of solid tumors harbor KRAS mutations). KRAS interaction with Guanidine Exchange Factors (GEFs) is crucial for its activation, with SOS1 being the predominant GEF. SOS1 inhibition is thus expected to be an effective strategy for targeting the downstream signaling pathway, resulting in anti-proliferative activity in RAS-driven cancers. We have identified multiple potent and selective SOS1 inhibitors, demonstrating significant reduction of GEF activity in a dose-dependent manner. The lead compounds show anti-proliferative activity across a panel of WT and mutant KRAS cell lines, and are synergistic with MAPK pathway inhibitors including KRASG12C inhibitor Sotorasib. Correspondingly, significant reduction in PD biomarkers, pERK and pAKT is demonstrated in KRAS mutant cell lines. PK-PD correlation is also established in a tumor bearing mice model, with dose-dependent reduction of both pERK and pAKT. The lead compound shows good ADME properties, and is orally bioavailable, making it amenable for further in vivo profiling.

Citation Format: Sanjita Sasmal, Sukanya Patra, Venkatesham Boorgu, Mahesh Yanamadra, Ashok Ettam, Nagaraju Dunaboyina, Githavani Kummari, Ram Mohan Yengala, Balakrishna Lakhavath, Jayita Das, Satheesh Sunkanapally, Pravalika Reddy, Megha Mariam Mathew. Discovery of potent, orally bioavailable, SOS1 inhibitors for KRAS-driven tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6368.

Clonal propagation of Enset (Ensete superbum (Roxb.) Cheesman) through shoot tip cultures

The morphogenetic potential of the shoot tip explants ofEnsete superbum (Roxb.) Cheesman, a wild relative of the cultivated bananas, was investigated and an effective clonal propagation method devised. Shoot tip explants grown in modified MS medium containing 1.5 mg l(-1) BAP and 1 mg l(-1) KIN developed corms which on transfer to medium containing 3 mg l(-1) IBA and 1.5 mg l(-1) BAP, regenerated a large number of shoots from the surface of the corm, the origin of which was traced to single hypodermal cells. Shoots were rooted on a half-strength MS medium salts containing 3 mg l(-1) IBA and 0.1 mg l(-1) BAP. The rooted plantlets were hardened and planted in the field where the plants looked normal.

Heterotopic ossification of the extensor tendons in the hand associated with traumatic spinal cord injury

Heterotopic ossification (HO) occurs in spinal cord injury (SCI), most frequently in the large joints such as hips, shoulders, knees, and elbows. It always occurs below the level of neurologic lesion. In the upper extremities, HO associated with SCI usually involves the flexor side of the involved joint. HO has only been reported once to involve the hands and rarely develops parallel to the long bones. We present a 44-year-old male with C5 traumatic SCI who developed HO involving the extensor tendons of one hand. The HO was discovered four months after the SCI and involved the extensor sheaths of the second, third, and fourth digits, from the metacarpal-phalangeal joint to the proximal inter-phalangeal joint. The patient had been improving neurologically with poor to fair extension of the right wrist allowing for tenodesis finger flexion, but with the onset of HO he lost some functional grasp. Diagnosis, possible etiology, and treatment (including options of radiation therapy and surgery) are discussed.

Etiology of acute diarrhoea among children in developing countries: a multicentre study in five countries

A 2-year etiological survey of acute diarrhoea in children aged 0-35 months who were attending treatment facilities was carried out using a standardized protocol in five hospitals in China, India, Mexico, Myanmar, and Pakistan. A total of 3640 cases of diarrhoea and 3279 age- and sex-matched controls were studied; about 60% of the patients were aged less than 1 year and 60% were male. An enteric pathogen was detected in 68% of the cases and in 30% of the controls. In all the study centres, the pathogens most strongly associated with disease were rotavirus (16% of cases, 2% of controls), Shigella spp. (11% of cases, 1% of controls) and enterotoxigenic Escherichia coli (16% of cases, 5% of controls). Rotavirus was commonest among 6-11-month-olds, accounting for 20% of all cases in this age group; 71% of all rotavirus episodes occurred during the first year of life. Shigella spp. were commonest among those aged 12-23 months and 24-35 months, accounting for 22% and 27% of the cases, respectively. The proportion of cases that yielded no pathogen was inversely related to age, being highest (41%) among infants below 6 months of age and lowest (19%) among those aged 24-35 months. These results suggest that microbe-specific intervention strategies for the control of childhood diarrhoeal diseases in developing countries should focus on rotavirus, Shigella spp. and enterotoxigenic E. coli.